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Sprockets Attributes: Specification Reference for Distributor Catalogs

Sprockets are toothed wheels that engage roller chain to transmit power. PT and bearings distributors sell them to plant maintenance, OEM machine builders, and conveyor integrators. The volume sits in ANSI 25 through 140 in single, double, and triple strand, plus ISO B-series (08B–24B), double-pitch conveyor sizes (C2040–C2082), and idler sprockets with pressed-in bearings.

The data problem is that the spec lives inside the part number, not in fields. "60BS15H x 1" encodes chain size, hub style, strands, tooth count, hardened teeth, and finished bore — six attributes in one string. Manufacturers publish the real dimensions (LTB, minimum plain bore, hub diameter, maximum bore) in PDF tables; what reaches the ERP is a description line.

Variant count compounds it. Each chain size crosses tooth counts from roughly 8 to 120, four hub styles, plain versus finished versus bushed bores, and one to three strands. And chain size as free text quietly mixes incompatible families: ANSI 60 and ISO 12B share a nominal 3/4 in pitch but differ in roller diameter and inner width.

Core

Every SKU needs these. Without them the record is not a product, it is a row.

Industry Chain Size
enum
60

The first facet every buyer touches. Determines pitch, roller diameter, and tooth form. Wrong size means the chain will not seat.

Chain Pitch
number · in
0.750 in (ANSI 60)

Distance between roller centers. Drives pitch diameter math and confirms the chain family when the size code is ambiguous.

Number of Teeth
number
15

Sets drive ratio and speed. Buyers filter on exact tooth count when replacing an existing sprocket in a drive.

Number of Strands
enum
Double (duplex)

Single, double, or triple must match the chain. A duplex chain on a simplex sprocket is an immediate no-fit.

Hub Style
enum
Type B — hub on one side

Type A (no hub), B (one side), C (both sides), D (detachable). Governs LTB, maximum bore, and keyway depth available.

Bore Type
enum
Plain bore (reboreable)

Plain (reboreable), finished, QD bushed, taper-lock bushed, or bearing bore. Decides whether the part ships ready to mount.

Bore Diameter
number · in
1.000 in (finished, keyed)

Must match the shaft. On plain-bore stock this is the as-shipped rough bore, not the finished shaft size.

Material
enum
1045 carbon steel

1045 for hardened drives, 1018 for plate, 304/316 stainless for washdown, UHMW/nylon where corrosion or chain noise matters.

Manufacturer Part Number
identifier
60BS15H x 1

The cross-reference key. Maintenance buyers search the number stamped on the failed part, not a description.

Differentiating

What buyers actually compare on. This is where catalogs win or lose the filter.

Bushing Type & Size
enum
QD SK

QD (SDS, SK, SF, E) or Taper-Lock (1108, 1610, 2012). The bushing carries the bore and is usually a separate SKU.

Maximum Bore Diameter
number · in
1.4375 in (limited by 2.25 in hub dia)

The rebore ceiling, limited by hub diameter and keyway depth. Machine shops need it before they cut.

Keyway & Setscrew Spec
text
1/4 x 1/8 in keyway; two 3/8-16 setscrews

Finished-bore sprockets carry a keyway on tooth center plus two setscrews. Buyers verify key size against the shaft.

Hardened Teeth
boolean
true (H suffix — 60BS15H)

Recommended at 25 teeth or fewer, and in high-speed or abrasive drives. The H suffix is the only clue in most catalogs.

Pitch Diameter
number · in
3.607 in (60, 15T)

Buyers compute drive ratio and chain speed from PD. Calculated as pitch / sin(180/N).

Outside Diameter
number · in
3.98 in

Clearance check against guards, housings, and adjacent components in a retrofit.

Compliance & identifiers

Standards, regulatory data, and the identifiers channels reject you for missing.

Governing Standard
enum
ASME B29.1

ASME B29.1 (precision roller chain), B29.100 (double-pitch), ISO 606 / DIN 8187 (B-series). Separates incompatible families.

Country of Origin
enum
United States

Required for customs, government and Buy American contracts, and for marketplace item setup.

GTIN / UPC
identifier
00612345678901

Required by marketplaces and by distributor item-setup systems. Without it the SKU cannot be listed.

The fields that aren't in the schema at all

What most sprockets catalogs are missing.

The table above is the schema most catalogs already have. These are the attributes that usually aren't in it — each one surfaced by a signal from the live market rather than by an audit of what's already there. This is what Anglera's Schema Foundry does on a real catalog, in this category.

Supplier signal
+ Length Thru Bore (LTB)

Martin and Tsubaki dimension tables publish LTB for every B- and C-hub sprocket. Distributor PDPs typically stop at bore, OD, and teeth — there is no LTB field to populate.

Sprocket will not fit between a bearing and a shaft shoulder. Buyer discovers it at install, part comes back as a return on a machine-down order.

Supplier signal
+ Minimum Plain Bore / Maximum Bore

Plain-bore sprockets are sold specifically to be rebored, yet catalogs list only the as-shipped stock bore. The MPB and max-bore pair sits in the manufacturer table.

Machine shop cannot quote without the rebore ceiling. Buyer calls a competitor who publishes it, or bores through the hub wall and scraps the part.

Search signal
+ Hardened Teeth flag

Manufacturer numbers carry an H suffix, so 60BS15 and 60BS15H sit in the catalog as unrelated SKUs. Buyers search 'hardened sprocket' and land on no facet at all.

A 13-tooth drive gets spec'd unhardened, teeth hook and wear early, and the failure comes back as a warranty claim against the distributor.

Search signal
+ Bushing Type & Size

Buyers search '60 sprocket SK bushing'. The bushing series is embedded in the part number rather than exposed as a field, so bushed sprockets are unfilterable.

Sprocket ships without the matching bushing — a separate SKU — so the line arrives unmountable and the next RFQ goes elsewhere.

Competitor signal
+ Chain Series (ANSI vs ISO B-series vs double-pitch)

'60' and '12B' both land in a free-text Chain Size field at a near-identical nominal pitch, with no series attribute to keep the two families apart.

ISO chain gets ordered against an ANSI tooth form. Rollers do not seat correctly, the drive runs rough, and the return is blamed on the part.

How Schema Foundry finds these

Messy in, governed out.

The same value, spelled every way power transmission & bearings suppliers spell it. A filter only works once they agree.

Industry Chain Size
#6060-1ANSI 60RC60No. 6060 Chain
ANSI 60

Do not fold 12B-1 into this bucket. ISO 12B is 19.05 mm pitch with a different roller diameter and inner width.

Hub Style
Type BB HubSingle HubOne Side HubHub One SideBS
Type B — hub on one side

Hub style sets LTB, maximum bore, and keyway depth. Left as free text, it cannot drive a fitment rule.

Number of Strands
Single1SimplexDuplex2 StrandDouble Strand
Duplex (2 strand)

Suppliers mix ANSI (single/double) and ISO (simplex/duplex) wording in the same feed, splitting one facet into two.

Bore Type
Plain BoreRough BoreReboreableStock BoreFinished BoreMST
Plain bore (reboreable)

'Stock bore' means finished-and-keyed at some suppliers and unmachined at others. It has to be resolved, not passed through.

What buyers ask

Every one of these should be answerable from the attributes above. If it isn't, that's a gap.

  • Will a 60-1 sprocket run 12B chain, or do I need a different tooth form?
  • What's the largest bore I can machine into a 50B15 hub?
  • Do I need hardened teeth on a 13-tooth drive sprocket?
  • Which QD bushing fits this sprocket, and is it included in the price?
  • What's the pitch diameter? I need to work out my drive ratio.
  • Will this fit between my bearing and the shaft shoulder?
  • Is this cut for C2040 standard roller or C2042 oversize roller chain?
  • Is the keyway on tooth center, and how many setscrews does it have?

What channels require

The same SKU, different mandatory fields per destination.

PTDA / BSA PIE (Product Information Exchange)
Manufacturer Part NumberBrandIndustry Chain SizeNumber of TeethBore Type & DiameterDatasheet / dimension PDF
Amazon Business
GTIN / UPCBrandManufacturer Part NumberItem weight & dimensionsMain image on whiteCountry of Origin
Distributor faceted search (own site)
Industry Chain SizeNumber of TeethNumber of StrandsHub StyleBore TypeBore Diameter
Grainger / MSC supplier item setup
Manufacturer Part NumberUPCCountry of OriginShipping weight & dimensionsGoverning StandardMaterial

Sprockets data, in practice

What's the difference between plain bore, finished bore, and QD bushed sprockets?

A plain-bore sprocket ships with an undersized rough bore intended to be machined to the shaft — the buyer or their shop cuts the final bore, keyway, and setscrew holes. A finished-bore sprocket is already machined to a specific shaft diameter, with a keyway aligned to tooth center and typically two setscrews, one over the keyway and one at 90 degrees. A bushed sprocket has a tapered seat that accepts a QD or Taper-Lock bushing; the bushing carries the actual bore and keyway and is nearly always a separate SKU. The practical consequence for a catalog: bore diameter means three different things across those three families, so it needs a Bore Type attribute alongside it.

Is ANSI 60 the same as ISO 12B?

No. ANSI 60 has a 0.750 in pitch and ISO 12B has a 19.05 mm pitch, which is the same number, and that coincidence is exactly what causes the mix-ups. The two differ in roller diameter and inner link width, so the tooth form and tooth gap are cut differently. Chain from one series will not seat properly on a sprocket from the other. ANSI sprockets follow ASME B29.1; B-series metric sprockets follow ISO 606 / DIN 8187. Any catalog carrying both families needs a chain series attribute, not just a size string — otherwise the two collapse into one facet value and buyers order across families without a warning.

Can I run double-pitch chain on a standard roller chain sprocket?

Partly, and the exception is what causes returns. Double-pitch sprockets in higher tooth counts (roughly 30 and up) are commonly cut on a standard single-pitch tooth form, with the chain engaging every other tooth. Below that, a true double-pitch tooth form is needed for correct roller seating. The exception is oversize-roller chain — C2042, C2052, and the rest of the C20x2 family — where the roller diameter is larger than the sidebar height. Those require sprockets cut for the larger roller regardless of tooth count; a standard-roller sprocket will not seat them. Catalogs that list C2040 and C2042 under one chain size lose this distinction entirely.

When do sprocket teeth need to be hardened?

Hardening is generally recommended at 25 teeth or fewer, because fewer teeth means each one carries more load and engages more often per shaft revolution. It also applies in high-speed drives, abrasive or dirty environments, and anywhere the sprocket is expected to outlast several chains. Manufacturers indicate it with an H suffix in the part number — 60BS15H is the hardened version of 60BS15. Because the flag lives in the number and not in a field, most catalogs carry both variants as unrelated SKUs with no way to filter for hardened teeth, and no way to warn a buyer specifying a low-tooth-count drive.

More power transmission & bearings schemas

Ball BearingsGearboxes & Speed ReducersLinear BearingsRoller ChainShaft CouplingsV-Belts

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