Sprocket 20B-3 z=39 with hub

Product Description

Sprocket 20B-3 z=39, with hub

Sprocket 20B-3 with hub, 39 teeth, triplex (three-strand) - a product matched to chain with a pitch of 31.75 mm (1 1/4"). The material is C45E carbon steel (EN 10083-1), and the teeth remain unhardened (without induction hardening) - in accordance with DIN 8187 / ISO 606; this version is easier to machine over the entire depth of the sprocket.

Technical data

Frequently asked questions

How do you select a sprocket when the machine lacks space for a larger pitch?

In such a situation, a better solution than increasing the pitch is often to use a multi-strand chain and sprocket of the same (smaller) pitch - several strands together carry a greater load without increasing the sprocket diameter.

How do I determine the centre distance between the driving and driven sprockets?

The centre distance should provide an adequate chain wrap angle on the smaller sprocket (usually a minimum of about 120°) and sufficient chain length so that the number of links is a whole number, preferably even. Too small a centre distance increases the meshing frequency and accelerates wear, while too large a one leads to excessive chain sag.

Is it possible to order a single trial piece of the sprocket before placing a larger order?

Yes, catalogue items can be ordered in any quantity, including a single piece for testing or verification before a larger series order.

Can the hub of a sprocket have a different hardness from the toothed rim?

Yes, and in practice this is usually the case - in the version with induction-hardened teeth, only the toothed rim is hardened, while the hub remains soft so that it can be freely turned and a keyway can be cut in it. This solution combines tooth wear resistance with ease of machining the hub.

Where is this product used?

20B-3 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.