Sprocket 20B-1 z=76 with hub, Cast iron

Product Description

Sprocket 20B-1 z=76, with cast iron hub

Sprocket 20B-1 (pitch 1 1/4" - 31.75 mm), simplex, 76 teeth, with hub. The material is grey cast iron - an economical solution with good vibration damping that proves itself in drives running at constant speed; the hub has a pilot bore that must be bored out individually to suit the shaft.

Technical data

Frequently asked questions

What forces act on the key in a sprocket and how can it be prevented from shearing?

The key transmits the entire shearing torque between the shaft and the sprocket. Make sure it is made of suitable quenched and tempered steel, has an accurate fit in the keyway and that the machine is not subjected to extreme jerks without an overload clutch.

Does a larger number of teeth always mean a longer service life for the sprocket?

Largely yes - the more teeth are engaged, the lower the load on each individual tooth, and the chain runs over a larger wrap angle, which reduces dynamic impacts. Very small sprockets (with fewer than fifteen or so teeth) wear the fastest and are best avoided if the drive design allows.

Can a sprocket with a technological bore be installed without additional machining?

No - the technological bore is deliberately too small to fit a typical shaft. It must be bored on a lathe to the required diameter and, if necessary, a keyway cut according to the requirements of the specific machine.

How can you check whether the chain in an existing drive is already excessively elongated (stretched)?

Stretch out a section of a dozen or so chain links and compare its length with the catalogue dimension - an elongation of more than approx. 2-3% means the chain is due for replacement. A stretched chain no longer seats properly on the sprocket teeth, which accelerates the wear of both components, so it is better to replace it before it damages the sprocket as well.

Does a cast iron sprocket require a different chain than a steel sprocket of the same pitch?

No - the tooth geometry and pitch are identical to those of the steel version of the same size, so the cast iron sprocket works with the same chain. The difference lies in the material of the hub and rim: cast iron dampens vibrations better and is cheaper, but withstands impacts and operation at high rotational speeds less well than steel.

Where is this product used?

20B-1 sprockets are used in industrial drive transmissions: conveyors, feeders, packaging machines and production lines where precise, repeatable torque transmission matters.

When placing your order, please check the current stock level of this gear - the lead time depends on it and is clearly stated according to the quantity available in the given warehouse.

Product photos are for illustrative purposes only.