Sprocket 20B-3 (1 1/4") z=21 with hub, steel

Product Description

Sprocket 20B-3 (1 1/4") z=21 with hub, steel fits 20B-3 roller chain (European standard DIN 8187 / ISO 606), triple-strand (triplex), with a pitch of 31.75 mm (1 1/4"). It has 21 teeth and is made of structural steel.

The sprocket has a one-sided hub with a diameter of 140 mm, welded to the plate, and a pilot bore of Ø25 mm, which is bored to the shaft size and completed with a keyway or a set screw hole. The total width of the sprocket is 115 mm.

Technical data

Applications

It works well in high-power agricultural machinery, presses and feeder drives in processing plants. The triple-strand version is chosen for very heavily loaded drives where there is no room for a chain with a larger pitch.

Frequently asked questions

Which chain does the 20B-3 z=21 sprocket fit?

20B-3 roller chain to European standard DIN 8187 / ISO 606, with a pitch of 31.75 mm. A triplex sprocket requires a triple-strand (triplex) chain.

Does it fit ASA 100 chain?

No. ASA 100 chain (American standard) has the same pitch and roller diameter, but a different inner width (19.05 mm instead of 19.56 mm). The 20B sprocket is designed for European-standard chain, so the two systems should not be mixed.

What causes wear on the sides of the teeth?

Most often misaligned sprockets. The chain does not run straight and its plates rub against the sides of the teeth. In this case the sprockets must be realigned in one plane.

How do I check sprocket run-out after installation?

A dial indicator on a magnetic stand is used. Place the tip against the rim or side of the sprocket and turn the shaft, reading the deviations. Excessive run-out usually means a crooked bore or a damaged shaft.

How does tooth wear affect machine operation?

Worn teeth make the chain engage the sprocket unevenly and abruptly. This causes vibrations that are passed on to shafts and bearings and accelerate wear of the whole drive.

What does the lead time depend on?

When ordering, please check the current stock level of this sprocket - the lead time depends on it and is clearly stated according to the quantity available in each warehouse. The stock level is shown above the product price and may vary depending on the warehouse.

Product photos are for illustration purposes only.