Duplex Chain Sprocket 12T - 24T Pitch 19.05mm For #60 12A Roller Chain 45#Steel

Your drive ratio is determined by dividing the driven sprocket's tooth count by the driver sprocket's tooth count. For example, pairing a 12T driver with a 24T driven sprocket gives a 2:1 reduction — the output shaft turns at half the speed but with twice the torque. Start by calculating the speed and torque you need at the output shaft, then select tooth counts that achieve that ratio within the 12T–24T range available here.

No. These are duplex (double-strand) sprockets machined with two parallel tooth rows to match #60 / 12A duplex roller chain. Using them with single-strand #60 chain will result in misalignment and rapid wear. If you need a simplex sprocket for #60 chain, please check our simplex sprocket listings.

Bore diameter varies by tooth count — please refer to the variant options on this page for the exact bore size of each model. The bore is finish-machined and accepts standard keyways. If you need a non-standard bore diameter, we recommend consulting a local machine shop to bore the sprocket to your shaft size after purchase, as the 45# steel machines cleanly.

The 45# steel construction provides solid tensile strength (typically 600–800 MPa depending on heat treatment), and the duplex configuration doubles the load-carrying capacity compared to a simplex sprocket of the same pitch. Exact working load depends on your RPM, chain tension, and lubrication conditions. For critical load calculations, refer to the ANSI B29.1 chain drive design standard or consult an engineer for your specific application.

Each sprocket has a protective surface finish that provides moderate resistance to oxidation in typical workshop and outdoor conditions. For continuous exposure to moisture, salt spray, or chemicals, we recommend applying a compatible chain lubricant regularly and pairing with a corrosion-resistant roller chain. For highly corrosive environments, consider stainless steel sprocket options.

Confirm two things: (1) your chain is #60 or 12A duplex roller chain with a 19.05 mm pitch, and (2) your chain is double-strand (duplex), not single-strand. You can measure chain pitch by placing the chain flat and measuring center-to-center between any two roller pins 10 links apart, then dividing by 10 — the result should be 19.05 mm (¾ in). If both conditions match, these sprockets are compatible.

#60 is the ANSI designation and 12A is the ISO 606 designation for the same chain standard — both refer to roller chain with a 19.05 mm (¾ in) pitch. These sprockets are machined to this shared pitch standard and are compatible with chain sold under either designation, as long as it is the duplex (double-strand) variant.