Sprocket 20B-3 z=57 with hub, Cast iron

Product Description

Sprocket 20B-3 z=57, with cast iron hub

Sprocket 20B-3 (pitch 1 1/4" - 31.75 mm), triplex (three-strand), 57 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

What causes premature wear of the side faces of the teeth?

This is most often the result of misalignment of the sprockets on the shafts (so-called lateral runout of the drive). The chain does not run straight, and its inner plates catch on the sides of the teeth, wearing them down to bare metal. The system must be realigned immediately.

Is a sprocket with hub suitable for reversing drives (with a change of rotation direction)?

Yes, the tooth geometry of a sprocket is symmetrical and has no preferred direction of operation, so the sprocket can be used in drives that change direction of rotation. In such systems, correct chain tension on both sides is particularly important, because when reversing, each side alternately becomes the working side.

What does the marking "z=X" on a sprocket mean and why is it so important when ordering?

"z" is the number of teeth of the sprocket - together with the pitch and the number of chain strands, it unambiguously defines the sprocket geometry (pitch circle and outside diameter). Ordering a sprocket with the wrong "z" usually means that it will not work correctly with the second sprocket already in the machine, and a different transmission ratio than intended will result.

Is it worth using guards on sprockets and the entire drive?

Yes - a guard protects operators from contact with moving parts and at the same time limits the ingress of dust and moisture to the chain, which genuinely extends its service life. In many industrial machines, a chain drive guard is also an occupational safety requirement.

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?

This type of sprocket is used in drives of agricultural and industrial machinery, including screw and bucket conveyors, feed conveyors, packaging machines and internal transport systems.

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.