Sprocket 12B-3 z=38 with hub, Cast iron

Product Description

Sprocket 12B-3 z=38, with cast iron hub

Sprocket 12B-3 (pitch 3/4" - 19.05 mm), triplex (three-strand), 38 teeth, with hub. Cast iron version of the sprocket - the tooth geometry is identical to the steel version with the same pitch and number of teeth; the bore in the hub is a pilot (preliminary) bore, and the exact size is achieved by turning.

Technical data

Frequently asked questions

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.

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.

How should large-diameter sprockets be transported and stored to prevent deformation?

Large sprockets are best stored and transported lying flat on a level, stable surface, rather than resting on the toothed rim alone, which is more susceptible to local deformation. When lifting, it is advisable to use slings passed through the hub bore rather than hooking them onto individual teeth.

How does material quality prevent the teeth from "shearing" during sudden machine jerks?

Soft, uncertified sheet metal deforms under a sudden jerk - the teeth bend over. Steel from a certified melt, correctly heat-treated, has a high yield strength and withstands a torque surge without permanent deformation.

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?

12B-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.