Sprocket 20B-3 (1 1/4") z=76 with hub, cast iron

Product Description

Sprocket 20B-3 (1 1/4") z=76 with hub, cast iron is designed for 20B-3 roller chain (European standard DIN 8187 / ISO 606), triple-strand (triplex), with a pitch of 31.75 mm (1 1/4"). It has 76 teeth and is made of EN-GJL-250 cast iron.

The sprocket has a one-sided hub with a diameter of 200 mm and a pilot bore of Ø60 mm, which is bored to the shaft size and completed with a keyway or a set screw hole. The total width of the sprocket is 140 mm.

Technical data

Applications

It is used in sawmills, cement plants and bulk material handling lines. The triple-strand version is chosen for very heavily loaded drives where there is no room for a chain with a larger pitch. The cast iron design works well for large sprockets in reduction gears, where rigidity and vibration damping matter.

Frequently asked questions

Which chain does the 20B-3 z=76 sprocket fit?

20B-3 roller chain to European standard DIN 8187 / ISO 606, with a pitch of 31.75 mm. A triplex sprocket requires a triple-strand (triplex) chain.

Does it fit ASA 100 chain?

No. ASA 100 chain (American standard) has the same pitch and roller diameter, but a different inner width (19.05 mm instead of 19.56 mm). The 20B sprocket is designed for European-standard chain, so the two systems should not be mixed.

How do I check the pitch of a sprocket?

The sprocket pitch matches the chain pitch - it is the distance between the centres of adjacent teeth measured on the pitch circle. The easiest way to check it is to place a section of matching chain on the sprocket: it should sit on the teeth without tension. This sprocket has a pitch of 31.75 mm (1 1/4").

How is the pitch diameter of a sprocket calculated?

The pitch diameter Dp is the circle along which the chain rollers travel. It is calculated with the formula: pitch divided by the sine of (180° / number of teeth). For this sprocket it is 768.32 mm, and the outside diameter De is 783.5 mm.

When should I choose a sprocket with hub and when a plate wheel?

A sprocket with hub is chosen when it transmits torque directly from the shaft via a key - the hub provides a longer contact surface with the shaft and a more stable fit. Plate wheels are used mainly when the wheel is fixed to an existing flange or drum, or when there is little space on the shaft.

What does the lead time depend on?

When ordering, please check the current stock level of this sprocket - the lead time depends on it and is clearly stated according to the quantity available in each warehouse. The stock level is shown above the product price and may vary depending on the warehouse.

Product photos are for illustration purposes only.