Glossary of Terms for Chains, Sprockets, and Accessories (Excerpt from JIS B 1812:2015)
2026/05/07
[Scope
] This standard specifies the terminology and definitions related to chains, sprockets, and their accessories used for power transmission and material handling. *This technical document
does not include any figures. Figures and the full text are available on the "Japanese Industrial Standards Committee" website.
*Due to space limitations, exponents are displayed as 10^6 in this document
. *In this standard, the term "sheave" is used in English. Although "pulley" is a synonym, the pulley used to wind elevator ropes, for example, is referred to as a sheave.
1. Types of Chains
1) By structure
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Chain | A general term for a chain in which external and internal links are alternately connected, and the joints can bend. | chain |
| Roller chain | A chain with rollers. | roller chain |
| A-series chain | Roller chains designated by numbers based on U.S. ASME standards. | A-series chain |
| A-series H-class chain | A roller chain in which the thickness of the outer and inner plates of the A series chain has been increased by one size to improve the minimum dynamic strength. | A-series heavy chain |
| A-series HE-class chain | A roller chain with the same dimensions as the A-series H-class chain but with a higher minimum tensile strength. | A-series extra heavy chain |
| B-series chain | Roller chains with designations based on European BS/DIN standards. | B series chain |
| Bushing chain | Chain without rollers. | Bush chain |
| Single-row roller chain | Single-row roller chain | simplex roller chain |
| Double-row roller chain | A chain formed by stacking two single-row roller chains in the longitudinal direction of the pins to form a single unit. | Duplex roller chain |
| Three-row roller chain | A chain formed by stacking three single-row roller chains in the longitudinal direction of the pins to create a single unit. | Triplex roller chain |
| Multi-row roller chain | A general term for roller chains with two or more rows. | multiplex roller chain |
| Short-pitch roller chain | A roller chain specified in JIS B 1801. Note: This is a roller chain used for general power transmission; it is sometimes referred to as a short-pitch roller chain in contrast to a double-pitch roller chain. | short-pitch roller chain |
| Double-pitch roller chain | A roller chain with a pitch twice that of a short-pitch roller chain. | double-pitch roller chain, double-pitch conveyor chain |
| leaf chain | A chain made by stacking plates and connecting them with pins only. | Leaf chain |
| Side-bow chain | A chain designed so that the pins can bend in an arc along their longitudinal axis. | Side Bow Roller Chain |
| Silent chain | A chain consisting of stacked toothed plates that mesh with the sprocket, along with guide plates and pins to prevent them from coming off. | silent chain inverted tooth chain |
| Sealed chain | A chain in which a seal ring is inserted between the outer and inner plates to seal lubricant between the pins and bushings. | Sealed Chain |
| Bushingless roller chain | A roller chain without bushings. | bushless roller chain |
| Gull chain | A chain consisting of plates and pins, where the pins mesh with a sprocket. | Galle chain |
| Pintle chain | A chain consisting of links (where the plate and bushing are integrated) and pins. | pintle chain |
| Detachable chain | A chain in which the links and pins are integrated, allowing for easy disassembly and reassembly. | detachable link chain |
| Block chain | A chain in which the inner links are composed of one or more blocks. | Block chain |
| Flat-top chain | A chain with hinge-like joints and flat plate sections. | flat top chain |
| Top plate chain | A chain with a flat plate attached to the top. | top plate chain |
| Crescent chain | A chain with a crescent-shaped plate attached parallel to the main plate, allowing it to move in a curved path on a horizontal plane. | crescent chain |
| Hollow-pin chain | A chain with hollow pins, allowing various attachments to be mounted using these holes. | hollow pin roller chain, hollow pin conveyor chain |
| Chain with attachments | A general term for chains used for conveying purposes by attaching attachments. | Chain with attachment |
| Chain with bent attachment | A chain with an attachment formed by extending a plate and bending the protruding tongue-shaped portion at a right angle. Note : In very rare cases, attachments may be bent at angles other than a right angle to suit the application. | Bent attachment chain |
| Chain with straight attachment | A chain with an attachment in which the plate is extended and the tongue-like protrusion is not bent. | straight attachment chain |
| Chain with extended pin attachment | A chain with an attachment featuring an extended pin that protrudes from the plate surface. | Extended pin attachment chain |
| Chain with side rollers | A chain with rollers mounted on extended pins on the outside of the plates. | Conveyor chain with outboard rollers |
| Chain with top rollers | A chain in which rollers are mounted on attachments that extend from the center plates between the chain links and protrude like tongues. | Top roller chain |
| Center roller chain | A chain with rollers on both sides that mesh with the sprocket and a large roller in the center. | Center roller chain |
| Double-speed chain | A chain that combines small-diameter and large-diameter rollers, enabling transport at a speed faster than the chain's running speed. | Double-speed chain |
| Guide roller chain | A chain in which guide rollers are attached via an attachment to prevent meandering or reduce resistance in curved sections. | guide roller chain |
| Crossbar chain | A chain formed by joining two roller chains with long pins to create a single unit. | Crossbar chain, twin-strand conveyor chain |
| Deep-link chain | A chain designed with taller plates to allow direct loading onto the plates. | Deep link chain, deep link conveyor chain |
| Combination chain | A chain composed of a combination of dissimilar materials, consisting of an inner link made of cast iron, cast steel, resin, etc., and a steel outer link. | Combination chain, combination conveyor chain |
| No-back-bend chain | A chain that uses plates or attachments to prevent bending in one direction, allowing it to transmit pushing force. | non-back-bend chain, pusher chain |
| Sleeve chain | A chain in which a self-lubricating sleeve is inserted between the pin and the bushing to prevent wear between them. | sleeve chain |
| Forged rivetless chain | A chain in which forged center links and side bars are connected by pins with heads at both ends. | Drop-forged rivetless chain |
| Drag chain | A chain in which links—comprising an offset plate and a bushing that acts as a scraper, welded together as a single unit—are connected by pins. | Welded-type cranked link drag chain, drag chain |
| Offset-type welded chain | A chain in which links—consisting of an offset plate and a bushing welded together as a single unit—are connected by pins. | Welded type cranked link chain |
| Sticker chain | A chain with plates featuring pointed triangular attachments. | Sticker chain |
| Heavy-duty chain | A chain designed for heavy-duty applications, consisting solely of offset links, allowing the number of links to be adjusted every pitch. | Heavy-duty cranked link chain, cranked link chain |
2) By Application
| Terminology | Definition | Corresponding English Terms (for reference) |
|---|---|---|
| Power Transmission Roller Chain | A chain used to transmit driving force from a prime mover to a driven machine. | short-pitch roller chain |
| Conveyor chain | A chain used to transport objects. | conveyor chain, solid pin conveyor chain |
| Bicycle chain | A chain used to drive the rear wheel of a bicycle. Note : Bushingless chains are often used for multi-speed systems. | cycle chain |
| Motorcycle chain | Drive chains for the rear wheel of a motorcycle and chains used within the engine. | motorcycle chain |
| Automotive chains | Chains primarily used within automobile engines. Note : Includes roller chains and silent chains. | automotive chain |
| Timing chain | A chain used to open and close the engine's intake and exhaust valves. Note: There are roller chains and silent chains. | timing chain |
| S-type and C-type chains for agricultural machinery | A chain used in machinery for harvesting crops. Note : Type S has gourd-shaped plates, while Type C has oval-shaped plates. | Type S and C agricultural roller chains |
| Agricultural feed chain | A chain used in combine harvesters to transport rice stalks by clamping them between triangular attachments. | Agricultural feed chain |
| Forklift truck chain | A chain used to raise and lower the forks of a forklift. | forklift truck chain |
| Hoist chain | A chain used to suspend a hoist. Note: Generally, leaf chains are used. | hoist chain |
| Multi-story parking system chain | A chain used to raise, lower, and move horizontally the pallets, buckets, etc., that carry vehicles in multi-level parking garages. Note: In other configurations, short-pitch roller chains are also used. | parking chain |
| Draw bench chain | A chain used to pull drawn material in a cold drawing machine. Note : Side roller, block chain, and leaf chain types are also available. | draw bench chain |
| Sluice gate chain | A chain used to raise and lower the gate for opening and closing a water gate. | water gate chain |
| Rake chain | A chain used to drive the rake that removes debris caught on the screen in a seawater dust removal system. | rake chain |
| Caterpillar chain | A chain with lugs used to drive a caterpillar track. | caterpillar drive chain |
| Trenching chain | A chain used in trenching machines for farmland. | trencher chain |
| Sugar mill chain | A general term for chains used in machinery that extracts raw sugar from sugarcane. | sugar mill chain |
| Cane carrier chain | A chain used to transport sugarcane stalks. | cane carrier chain |
| Intermediate carrier chain | A chain used for intermediate transport between the cane carrier and the bagasse carrier. | Intermediate carrier chain |
| Bagasse carrier chain | A chain used to transport sugarcane bagasse. | Bagasse carrier chain |
| Escalator step chain | A chain that moves the steps of an escalator. | Escalator step chain |
| Trolley conveyor chain | A chain used to circulate trolleys equipped with hooks for suspending goods. | trolley conveyor chain |
| Coil conveyor chain | A chain used to load and transport coils manufactured at steel mills. | Coil conveyor chain |
| Delivery chain | A chain used to transport paper in printing presses. | delivery chain |
| Pin oven chain | A chain used in the baking oven after cans are printed. | Pin oven chain |
| Sheet oven chain | A chain used in the curing and drying process after sheet material printing. | sheet oven chain |
| Tenter chain | A chain used to transport fabric or film while holding it in place. | tenter chain |
| Wrench chain | A chain used in place of a wrench. | wrench chain |
| Coupling chain | A two-row roller chain used for chain couplings. | flexible coupling chain |
| Saw chain | A chain with teeth used for cutting wood and other materials. | saw chain |
| Free-flow chain | A general term for chains capable of conveying items while allowing them to remain stationary. | Power and Free Conveyor Chain |
| Bucket elevator chain | A chain used in equipment for the vertical conveyance of powders and granular materials. | Bucket elevator chain |
| Water treatment equipment chain | Chains used in water treatment equipment. | water treatment chain |
| ATC chain | Chains used in automatic tool changers for machine tools. | Tool carrier chain |
2. Chain Components
1) Link
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Link | A general term for the individual elements that make up a chain. | link |
| Inner Link | A link in which two bushings are press-fitted into two inner plates. Note : Those with rollers on the outside of the bushings are called "roller-type inner links," while those without rollers are called "bushing-type inner links." | inner link, bush link |
| Outer link | A link in which two pins are press-fitted into two outer plates. | outer link |
| Rivet-type outer link | A link in which both sides of the pin are crimped by the outer link. | Rivet-type outer link |
| Split-pin type outer link | A type of outer link in which one end of the pin is secured by a cotter pin or other pin. | Cotter-type outer link |
| Connector link | A general term for links used in chain joints. | connecting link |
| Interference fit connecting link | A connecting link in which the fit between the connecting plate and the connecting pin is a loose fit. | Loose-fit connecting link |
| Tight-fit connecting link | A connecting link in which the fitting plate and fitting pin are in a press fit. | Press-fit connecting link |
| Clip-type connecting link | A connecting link featuring a connecting plate and clips, in which one end of two clip-type connecting pins is press-fitted into the outer plate, while the other end allows for easy installation and removal. | Spring clip connecting link |
| Split-pin type connecting link | A connecting link in which one end of two cottered pin-type connecting pins is press-fitted into an outer plate, and a connecting plate and cottered pin are inserted to allow the other end to be easily attached and removed. | connecting link with cottered pin |
| Offset link | A general term for links used when the total number of links in a roller chain or bushing chain is odd. | offset link |
| Single-pitch offset link | A link designed for odd-numbered chains, in which a single bushing is press-fitted into two offset plates, allowing for easy installation and removal of the offset pin. | Single offset link |
| 2-pitch offset link | A link designed for odd-numbered links, consisting of one offset link and one inner link connected by a rivet-type pin. | Double offset link |
2) Plate
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Plate | A general term for the plate-shaped components that make up the links of a chain. | plate |
| Outer plate | The outer link component of a chain into which the pin is pressed. | outer plate |
| Inner plate | A component of the chain's inner link, serving as a plate into which the bushing is pressed. | inner plate |
| Intermediate plate | A component of a multi-row chain's outer links, located between the outer plates. | intermediate plate |
| Connector plate | A component of a chain's connecting link that can be easily attached and removed. | connecting plate, detachable plate |
| Interference-fit connecting plate | A connecting plate in which the hole dimensions for the connecting pin are designed for a loose fit. | Loose-fit connecting plate |
| Tight-fit connecting plate | A connecting plate in which the hole dimensions for the fitting pin are designed for a press fit. | Press-fit connecting |
| Offset plate | A stepped plate used in offset link assemblies, with a bushing press-fitted into one end and a pin inserted or press-fitted into the other. | offset plate |
| Gourd-shaped plate | A plate shaped like a gourd. | waisted plate |
| Straight plate | A plate shaped like an oblong coin. | Straight-sided plate |
3) Pin
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Pin | A general term for the cylindrical components that make up the outer links of a chain. | pin |
| Rivet-type pin | A pin that is press-fitted into the outer plate and used by crimping both ends of the pin. | rivet-type pin |
| Split pin | A pin that is press-fitted into an outer plate, with one end crimped and the other end featuring a hole into which a cotter pin or similar fastener can be inserted. | Cotter type pin |
| Connector pin | A general term for pins used in connecting links. | connecting pin |
| Clip-type connecting pin | A pin used in clip-type connecting links. | Spring clip connecting pin |
| Split pin-type connecting pin | A pin used for cottered connecting links. | Cottered connecting pin |
| Offset pin | Pin used for offset links. | offset link pin |
4) Bush
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Bushing | A general term for components that are press-fitted into an inner plate and function as bearings with a hollow shape. | bush |
| Wound bush | A bush with a seam formed by rolling sheet metal. | Curled bush |
| Seamless bush | A bush with no seams. | seamless bush |
| Stepped bush | A bush with a section that is one size smaller where it is press-fitted into the inner plate. | Shouldered bush |
5) Laura
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Roller | A general term for components that rotate while in direct contact with sprocket teeth or rails. | Roller |
| Winding roller | A roller formed by rolling sheet metal, featuring a seam. | curled roller |
| Seamless roller | A roller with no seams. | seamless roller |
| Small roller | A roller with an outer diameter smaller than the plate height that rotates freely on the outside of the bushing. | Small roller |
| Large roller | A roller with an outer diameter larger than the plate height that rotates freely on the outside of the bushing. | large roller |
| Flange roller | A roller with a flange to prevent meandering. | flanged roller |
6) Attachments
| Terminology | Definition | Corresponding English Terms (for reference) |
|---|---|---|
| Attachment | A general term for chain components that have been modified from their standard shape. | attachment |
| Bent attachment | An attachment formed by extending a plate and bending the tongue-like protrusion at a right angle. Note : In very rare cases, attachments may be bent at angles other than a right angle to suit the application. | bent attachment |
| A-type attachment | An attachment in which a bent attachment is mounted on one of the paired plates of a link. Note : An attachment with one mounting hole at the bent attachment is designated A1, and one with two mounting holes is designated A2. | A attachment |
| K attachment | An attachment in which a bent attachment is mounted on both plates of a pair of links. Note : An attachment with one mounting hole per bent attachment is designated K1, and one with two mounting holes is designated K2. | K attachment |
| WA attachment | An attachment in which the width of the tongue-shaped protrusion is approximately equal to the total length of the plate. Note : There are types such as WA1 and WA2, depending on the number of mounting holes. | WA attachment |
| WK attachment | In the K attachment, an attachment in which the width of the tongue-shaped protrusion is made approximately equal to the total length of the plate. Note : There are variants such as WK1 and WK2 depending on the number of mounting holes. | WK attachment |
| Straight attachment | An attachment in which the plate is extended and the tongue-shaped protrusion is not bent. | Straight attachment |
| SA attachment | An attachment in which a straight attachment is mounted on one of the two plates that form a pair. Note : An attachment with one mounting hole is called SA1, and one with two mounting holes is called SA2. | SA attachment |
| SK attachment | An attachment in which a straight attachment is mounted on both plates of a pair of links. Note : An attachment with one mounting hole per straight attachment is designated SK1, and one with two mounting holes is designated SK2. | SK attachment |
| WSA attachment | An SA attachment in which the width of the tongue-shaped protrusion is approximately equal to the total length of the plate. Note : There are types such as WSA1 and WSA2, depending on the number of mounting holes. | WSA attachment |
| WSK attachment | An SK attachment in which the width of the tongue-shaped protrusion is made approximately equal to the total length of the plate. Note : There are variants such as WSK1 and WSK2, depending on the number of mounting holes. | WSK attachment |
| Deep Link Attachment | An attachment designed with a taller plate to prevent the load on the plate from interfering with the rollers. | Deep Link Attachment |
| G attachment | An attachment with mounting holes provided on the body of the plate. | G Attachment |
| GA attachment | An attachment in which one of the two plates forming a pair of links is a G attachment. Note : An attachment with a single mounting hole on a single plate is designated GA1, and one with two mounting holes is designated GA2. | GA attachment |
| GK attachment | An attachment in which both plates of a pair of linked plates are G attachments. Note : An attachment with one mounting hole per plate is designated as GK1, and one with two mounting holes per plate is designated as GK2. | GK attachment |
| Extension pin attachment | An attachment in which the pin is extended so that it protrudes from the plate surface. | Extended pin attachment |
| D1 attachment | An attachment in which one of the two pins on the outer link protrudes on one side. | D1 attachment |
| D3 attachment | An attachment in which one of the two pins on the outer link protrudes on one side. | D3 attachment |
| Hollow pin attachment | An attachment that uses hollow pins. | hollow pin attachment |
3. Basic Chain Dimensions
1) Chain body
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Pitch | The distance between the centers of the pins in one link. Note : This is the dimension used as the basis for chain length, and standard dimensions are specified for each nominal size. | pitch |
| Inner Link Width | The inner dimension of the inner link. Expressed as the minimum dimension. | minimum width between inner plates |
| Roller outer diameter | The outer diameter of the roller. Expressed as the maximum value. For roller chains, this refers to the roller outer diameter; for double-pitch chains, it refers to the small roller outer diameter. For bushing chains, it refers to the bushing outer diameter. | maximum roller diameter |
| Large roller outer diameter | The outer diameter of the large roller. Expressed as the maximum value. | maximum large roller diameter |
| Lateral pitch | The distance between the centerlines of each row in a multi-row chain | transverse pitch |
| Plate height | The height of the plates in the outer plate, inner plate, intermediate plate, connecting plate, and offset plate. Expressed as the maximum value. | maximum inner plate depth, maximum outer plate depth |
| Pin outer diameter | Pin diameter. Expressed as the maximum value. | maximum bearing pin body diameter |
| Bush inner diameter | The inner diameter of the bushing pressed into the inner plate. Expressed as the minimum value. | minimum bush bore |
| Outer width of inner link | The outer width dimension of the inner link. Expressed as the maximum value. | maximum width of outer link |
| Inner width of outer link | Inner width of the outer link. Expressed as the minimum value. | minimum width between outer plates |
| Pin length | The length of the pin. Expressed as the maximum value. | Maximum width over bearing pin |
| Fitting pin extension length | The difference in length between the main pin and the joint pin. Expressed as the maximum value. | maximum additional width for joint fastener |
| Plate thickness | Plate thickness. | plate thickness |
| Offset plate bending position | Distance from the center of the pin or bushing to the bending position. Expressed as a minimum value. | minimum offset link dimensions |
2) Attachments
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Vent Attachment Hole Diameter | The diameter of the mounting hole for the vent attachment. Expressed as a minimum value. | minimum hole diameter |
| Straight Attachment Hole Diameter | The diameter of the mounting hole for the straight attachment. Expressed as the minimum value. | minimum hole diameter |
| Vent attachment mounting height | The height from the center of the chain to the top surface of the vent attachment. | platform height |
| Attachment width | The width of the attachment. | attachment width |
| Attachment length | Distance from the center of the chain to the end of the attachment. | attachment distance |
| Center-to-center distance of vent attachment mounting holes | Center-to-center distance of K-attachment mounting holes. | transverse distance between hole centers |
| Attachment height | Height from the center of the chain to the tip of the straight attachment. | Straight attachment height |
| Straight attachment mounting hole height | Height from the center of the chain to the center of the straight attachment mounting hole. | height from chain center line |
| Attachment hole pitch | The distance between the two mounting holes on each of the A2, SA2, K2, and SK2 attachments. | Longitudinal distance between hole centers |
| Extension pin projection length | The length of the protruding portion from the plate surface to the tip of the extension pin. | pin extension |
4. Chain Performance and Characteristics
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Tensile Strength | The maximum tension exerted when a chain is gradually pulled until it breaks. | tensile strength |
| Minimum tensile strength | The minimum value established by statistical analysis of tensile test results. | minimum tensile strength |
| Average tensile strength | The average value of the tensile test results. | average tensile strength |
| Guaranteed tensile strength | The tensile strength guaranteed by the manufacturer. | warranted tensile strength |
| Elongation under load | The change in length resulting from the tensile force applied to the chain during a tensile test. | load elongation |
| Elastic elongation | An indication of the extent to which a chain stretches elastically when tension is applied. The chain returns to its original shape when the tension is removed. | elastic elongation |
| Plastic elongation | Permanent elongation caused by tension applied to the chain. | plastic elongation |
| F-N diagram | A diagram with stress amplitude on the vertical axis and the number of cycles to failure on the horizontal axis. | F-N diagram |
| Fatigue strength | A general term for fatigue limit and time-dependent strength. | fatigue strength |
| Time strength | The fatigue strength corresponding to the sloping portion of the F-N diagram. | fatigue strength at N cycles |
| Fatigue limit | The fatigue strength corresponding to the horizontal region of the F-N curve, i.e., the upper limit of stress that can withstand an infinite number of cycles. Also known as the endurance limit. | fatigue limit, endurance limit |
| Minimum fatigue strength | A comprehensive measure combining time strength and fatigue limit, established as the minimum value derived from statistical analysis of test results. | minimum fatigue strength |
| Minimum fatigue limit | The minimum value of the minimum fatigue strength relative to the fatigue limit. | minimum fatigue limit |
| number of endurance cycles | A predetermined number of cycles at which the fatigue test is terminated even if the chain does not fail. | number of cycles at endurance |
| Maximum allowable tension | The maximum allowable tension of the chain, determined based on its dynamic strength. | maximum allowable tension |
| Interference fit | A fit in which there is always a gap. Note : Generally, this corresponds to the combinations of a pin and a coupling plate hole, a pin and an intermediate plate hole, and a roller and a bushing. | loose fit |
| tight fit | A fit in which there is always a clearance. Note : Generally, this corresponds to the combination of a pin and an outer plate hole, or a bushing and an inner plate hole. | press fit |
| Cordal action | The phenomenon where the chain forms a polygon relative to the pitch circle when it engages with the sprocket. | chordal action |
| Speed fluctuation | A phenomenon in which the chain speed fluctuates even when the drive sprocket rotates at a constant speed due to chordal action. | Speed variation |
| Chain wear | A phenomenon in which the pins and bushings wear out due to sliding friction that occurs between them when the chain engages with the sprocket. | wear |
| Chain wear resistance | The property of a chain to resist wear. | wear resistance |
| Wear elongation limit | The wear elongation limit at which the chain begins to slip off the sprocket. | wear elongation limit |
| Initial wear elongation | The initial stage of chain wear elongation, during which the elongation increases significantly before transitioning to steady-state wear elongation. | initial wear elongation |
| Steady-state wear elongation | A state of gradual elongation following the initial elongation, before rapid elongation begins. | standard wear elongation |
| Rapid wear elongation | A state in which wear elongation increases rapidly. | extreme wear elongation |
| Bush and roller service life | The number of cycles until the roller collides with the sprocket tooth surface and the bushing or roller undergoes fatigue failure. | Life span durability |
| Flexibility | The degree to which the outer and inner links bend via the pins. | flexibility |
| Lateral bending | The tendency for the chain to bend in the direction of the pin's longitudinal axis due to gaps in various parts of the chain. | side bow |
| Side-bend radius | The radius of the arc formed when the chain is placed on a flat surface and forced to bend laterally. | minimum side bow radius |
| Extraction force | The force required to pull a pin or bushing out of a plate. | push-out force |
| Chatter | A phenomenon in which the chain pulsates due to stick-slip when the chain is in use. | stick-slip |
| Sway | A phenomenon in which the chain oscillates from side to side while in motion. | snaking |
| Twist | A rotational misalignment that occurs in the axial direction when the chain is allowed to hang freely. | twisting |
| Galling | A phenomenon in which pins and bushings seize up at high speeds. | galling |
| Reference length | A value calculated by multiplying the reference dimension of the chain pitch by the number of links. | basic length |
| Length tolerance | The range of lengths permitted relative to the chain's standard length. | tolerance of overall length |
| Tension difference | The difference in tension between adjacent links in a staircase test, which determines the minimum fatigue limit of the chain, and the standard deviation obtained from a finite-life test. | step size |
| Maximum tension | The maximum value of the cyclic tension applied to the chain during fatigue testing. | maximum force |
| minimum tension | The minimum value of the cyclic tension applied to the chain during a fatigue test. | minimum force |
| Average tension | The sum of the maximum and minimum forces applied to the chain during a fatigue test, divided by two. | mean force |
| Tension amplitude | Half the difference between the maximum and minimum forces applied to the chain during a fatigue test. | force amplitude |
| Mean fatigue strength | The test force, adjusted to a minimum force of 0, corresponding to a 50% probability of failure at a given number of cycles. | mean fatigue strength |
| Test tension | The maximum test force when the minimum test force used in the fatigue test is corrected to 0. | test force |
| Number of cycles | The number of cycles of force applied during the fatigue test. | number of cycles |
| Standard deviation | Standard deviation | standard deviation |
| Measured tension | The force applied when measuring chain length. | measuring force |
| Minimum dynamic strength | Fatigue strength after 3 × 10^6 cycles. | minimum dynamic strength |
5. Sprocket
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Sprocket | A general term for a toothed wheel mounted on a shaft in a chain drive system that meshes with a chain and rotates. | sprocket |
| Drive sprocket | In a chain drive, a sprocket mounted on the drive shaft. | driving sprocket |
| Driven sprocket | In a chain drive, a sprocket mounted on the driven shaft. | driven sprocket |
| Idler sprocket | A sprocket that rotates freely without being directly involved in power transmission and is used to adjust chain slack or the wrap angle. | idler sprocket |
| Single-row sprocket | A sprocket that meshes with a single-row chain. | sprocket for simplex chain |
| Double-row sprocket | A sprocket that meshes with a duplex chain. | Sprocket for duplex chain |
| 3-row sprocket | A sprocket that meshes with a 3-row chain. | Sprocket for triplex chain |
| Multi-row sprocket | A general term for sprockets that mesh with chains having two or more rows. | multiplex sprocket |
| Large sprocket | A drive or driven sprocket with a high number of teeth among those that mesh with a single chain. | large sprocket |
| Small sprocket | The sprocket with the fewest teeth among the driving and driven sprockets that mesh with a chain. | small sprocket |
| Flat sprocket | A flat sprocket without a hub. | plate sprocket |
| Single-hub sprocket | A flat sprocket with a hub on one side. | sprocket with hub on one side |
| Double-hub sprocket | A sprocket with hubs on both sides of the plate. | sprocket with hubs on both sides |
| Detachable hub sprocket | A sprocket with detachable hubs attached to a flat plate. | Sprocket with separated hub |
| Single-cut sprocket | A sprocket used with small roller-type double-pitch chains, where the tooth pitch is equal to the chain pitch. | single-cut sprocket |
| Double-cut sprocket | A sprocket used with small roller-type double-pitch chains, where the tooth pitch is approximately half the chain pitch. | double cut sprocket |
| Pitch circle diameter | The diameter of the circle circumscribing the tooth pitch of the sprocket. | pitch circle diameter |
| Tip circle diameter | The maximum diameter of the sprocket's tip. | tip circle diameter |
| root circle diameter | The maximum diameter at the root of the sprocket tooth. | root circle diameter |
| Root circle distance | The maximum dimension of the distance between the root circles of opposing teeth on a sprocket. | root distance |
| Maximum hub diameter and maximum groove diameter | The maximum diameter of the hub that does not interfere with the chain when the chain is engaged. | maximum hub diameter |
| Tooth width | The width of a single row of teeth that mesh with the chain. | tooth width |
| Total tooth width | The outer width dimension of the teeth on a multi-row sprocket. | total tooth width of n rows |
| Total width | Maximum width dimension of the sprocket. | hub length |
| Direct measurement method | A method of measurement in which a point micrometer or similar instrument is placed directly against the root of the opposing tooth for even-numbered teeth, and against the root of the tooth closest to the opposing position for odd-numbered teeth. | direct measurement |
| Overpin method | A method in which two pins are inserted into the opposing tooth roots for even-numbered teeth and into the tooth roots adjacent to the opposing positions for odd-numbered teeth, and a micrometer or similar instrument is applied to measure the outer diameter of the pins. | Over-pin method |
| Tooth root runout | The maximum value of runout on the tooth root surface when the sprocket is rotated. | radial runout of tooth root |
| Lateral runout | The maximum lateral runout of the tooth root surface when the sprocket is rotated. | Axial runout of tooth side surface |
| Tooth profile | The shape of the tooth cross-section in a plane perpendicular to the sprocket axis. | tooth profile |
| S-tooth profile | A tooth profile with no straight sections at the tooth root. | S tooth profile |
| U tooth profile | A tooth profile with a straight section at the base. | U tooth profile |
| ISO tooth profile | A tooth profile with a straight section at the tooth base and a cut-off tip. | ISO tooth profile |
| Tooth profile pitch | The distance between the centers of adjacent teeth. It is equal to the chain pitch. However, the tooth pitch of a double-cut sprocket is approximately half the chain pitch. | Chordal pitch equal to chain pitch |
| Lateral pitch | The center-to-center distance between adjacent tooth widths. It is equal to the chain's transverse pitch. | transverse pitch |
| Pressure angle | The angle formed between the tooth pitch centerline and the roller centerline acting perpendicular to the roller contact surface. Note : In bushing chains, "roller" is replaced with "bushing." | pressure angle |
| Transverse tooth profile | The cross-sectional shape of a tooth in a plane containing the sprocket axis. | transverse tooth profile |
| Number of teeth | Total number of teeth. | number of teeth |
| Effective teeth | Tooth profileNumber of teethTotal number of teeth.Number of teethNumber of working teeth | number of working teeth |
| Even-numbered teeth | A sprocket with an even number of teeth. | even number of teeth |
| Odd number of teeth | A sprocket with an odd number of teeth. | odd number of teeth |
| Integer number of teeth | A sprocket with an integral number of teeth for double-pitch chains. | Integral teeth |
| Fractional teeth | A sprocket with a fractional number of teeth for double-pitch chains. | fractional teeth |
6. Chain Accessories
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Tensioner | A general term for methods used to apply tension to a chain. Types include spring-type, screw-type, weight-type, hydraulic-type, and pneumatic-type. | tensioner |
| Chain splitter | A tool used to cut or join chains. | connect and disconnect tool |
| Leaf chain end fittings | Fittings attached to the ends of leaf chains. | clevis |
| Pulleys | A guide pulley used to hoist or redirect a leaf chain. | sheave |
7. Selecting a Chain
| Terminology | Definition | Corresponding English Terms (for reference) |
|---|---|---|
| Method for Selecting Transmission Capacity | A method for selecting a chain based on a power transmission capacity chart. | Maximum kW Rating Selection |
| Power Capacity | The power that the chain can transmit. Expressed in kW. | Maximum kW Rating |
| Chain Tension | The tension acting on the chain. | chain tension |
| Corrected chain tension | The tension acting on the chain, corrected by a correction factor. | corrected chain tension |
| Tension on the slack side | The tension generated on the slack side of the chain. Note: This is the tension required to prevent the chain from skipping. | slack side tension |
| Transmitted power | The power actually transmitted by the chain. | input power |
| Corrected transmitted power | Transmitted power corrected to account for the characteristics of the driving and driven components and the number of sprocket teeth. | Corrected input power |
| Safety factor | The value obtained by dividing the tensile strength of the chain by the operating tension acting on the chain. | safety factor |
| Chain speed | The speed of the operating chain. | chain speed |
| correction factor | A general term for factors used to adjust values based on the conditions under which the chain is used. | corrected factor |
| Multi-row coefficient | The ratio of the transmission capacity of a multi-strand chain to that of a single-strand chain, where the transmission capacity of the single-strand chain is set to 1. | multi-strand factor |
| Load factor | A factor used to correct the transmission power based on the magnitude of load fluctuations. | service factor |
| Speed factor | A coefficient used to correct chain tension based on speed. | Speed factor |
| Tooth count factor | A coefficient used to adjust chain tension based on the number of sprocket teeth. | teeth factor |
| Impact factor | A coefficient used to correct chain tension based on the ratio of inertia between the driving and driven machines and the amount of play in the transmission system. | shock factor |
| Unbalanced load factor | A coefficient that corrects for uneven tension acting on multiple chains. | unbalance load factor |
| Roller load capacity | The load that a roller can withstand under specified conditions. | maximum allowable load of roller |
| Speed correction factor | A coefficient used to correct the chain speed according to the chain pitch in the calculation formula for determining the transmission capacity based on the friction between the pin and the bushing. | speed modification factor |
| Transmission torque | The torque that the chain can transmit. | input torque |
| Calculated number of chain links | Value obtained by converting the chain length into the number of links | calculated number of pitches in chain |
| Number of chain links | The number of links obtained by rounding up the calculated number of chain links to avoid using offset links. | number of pitches in chain |
| Link count coefficient | A factor used to correct the center distance based on the difference in the number of teeth between the large and small sprockets. | factor for calculating the center distance based on the difference in the number of teeth |
| Maximum center distance | The maximum center distance between the two shafts. | maximum sprocket center distance |
| Approximate center distance | The center distance between two shafts, taking into account chain slack. | Approximate centre distance |
| Centre distance coefficient | A factor used to correct the calculated number of chain links based on the difference in the number of teeth between the large and small sprockets. | factor for calculating the number of links based on the difference in the number of teeth |
| Rotational speed ratio | The ratio of the rotational speed of the driven sprocket to that of the driving sprocket. | Speed ratio |
| Drive sprocket rotational speed | Rotational speed of the driving sprocket. | driving sprocket speed |
| Driven sprocket speed | Rotational speed of the driven sprocket. | Driven sprocket speed |
| Small sprocket speed | Rotational speed of the small sprocket. | Small sprocket speed |
8. Chain Installation and Maintenance
| Terminology | Definition | Corresponding English (for reference) |
|---|---|---|
| Axis Parallelism | The degree of parallelism between two axes (the deviation in distance between the two axes). | parallel measurement |
| Axis levelness | The angle of deviation from the horizontal plane. | axial measurement |
| Sag | The amount of slack on the loose side of the chain. | slack |
| Lubrication method | Recommended lubrication methods based on chain speed and nominal chain size. Note : Methods include frequent manual lubrication using an oiler or brush, drip lubrication, oil bath, disc lubrication, and forced lubrication. | methods of lubrication |
| Chain skipping | A phenomenon in which the chain jumps over the sprocket teeth. | jumping the sprocket teeth |
Other Technical Documents
↓You can download the following technical documents as a single PDF file.
Specifications
Hole Machining, Tolerances, and Fits
Calculations, Conversions, Formulas, and Units
Machine Elements
- Hexagon Socket Head Cap Screw Standards List | Excerpt from JIS B 1176
- Shapes and Dimensions of Hexagon Socket Set Screws (Excerpt from JIS B 1177-1997)
- Shapes and Dimensions of Hex Bolts (Component Grade A) (Excerpt from JIS B 1180-1985)
- How to Use Hex Socket Set Screws
- Mechanical Properties of Steel Bolts and Screws (Excerpt from JIS B 1051-2000)
- Shapes and Dimensions of Hexagonal Wrenches (Hex Wrenches/L-Wrenches/Hex Wrenches) (Excerpt from JIS B 4648:2008)
- List of Standards for Dimensions and Tolerances of Parallel Keys and Keyways (Excerpt from JIS B 1301-1996/JIS B 1301-1959 [Old JIS])
- Snap Rings (C-Type Retaining Rings/C-Rings) Standards and Dimensions List (Excerpt from JIS B 2804-2010)
- Shim Dimensions
- Ball Bearing Standard Dimensions Table - JIS Excerpt
Material Properties
Terminology
- Glossary of Electromagnetic Clutch and Electromagnetic Brake Terms (Excerpt from JIS B 1404-1:2005)
- Glossary of Screw Terms (JIS B 0101:2013)
- Glossary of Fit Tolerances (Excerpt from JIS B 0401-1:2016)
- Glossary of Terms for Chains, Sprockets, and Accessories (Excerpt from JIS B 1812:2015)
- Glossary of Friction Belt Transmission Terms (Excerpt from JIS B 1860:2018)
- Technical Drawing—Terminology (Excerpt from JIS Z 8114:1999)