Sprocket 28B-1 z=21 with hub

Product Description

Sprocket 28B-1 z=21, with hub

The sprocket 28B-1 shown is a simplex sprocket with 21 teeth, made with a hub, for chain with a pitch of 1 3/4" / 44.45 mm. Compliance with DIN 8187 / ISO 606 guarantees full interchangeability with a chain of the same pitch; the sprocket is made of C45E steel (EN 10083-1) in a non-hardened version - the standard choice for applications with moderate and medium load.

Technical data

Frequently asked questions

How can you tell whether a sprocket is still fit for further service or already due for replacement?

It is worth checking the tooth profile for visible chipping or the characteristic "hooked" shape, and also measuring the pitch circle diameter and comparing it with the catalogue dimension of a new sprocket. If the difference is visually noticeable or the chain starts to "jump", the sprocket is due for replacement.

What is a technological bore in a sprocket and why is it left?

We manufacture sprockets with hub with a small, so-called pilot (preliminary) bore. We leave it deliberately so that the customer (or workshop) can bore it precisely to the exact shaft size of their machine.

Can a sprocket be reconditioned, e.g. by hardfacing worn teeth?

Technically, hardfacing and re-milling the teeth is possible, but in practice it is rarely cost-effective - the cost of reconditioning is often close to the price of a new sprocket, and restoring the full precision of the tooth profile requires specialist machining. In most cases, replacing it with a new sprocket is the quicker and safer solution.

Do a newly fitted chain and sprocket require running-in after installation?

After installation, it is worth running the drive for a while without full load, observing the smoothness of operation and the bearing temperature - this allows installation errors (e.g. misalignment) to be detected before full load is applied. The tooth profile of the sprocket itself does not require running-in if the sprocket and chain have matching pitch and are made in accordance with the standard.

Where is this product used?

28B-1 sprockets operate in drives of construction machinery, goods lifts, aggregate conveyors and woodworking machines - wherever tooth durability under load 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.