Sprocket 20B-2 (1 1/4") z=39 with hub, steel

Product Description

Sprocket 20B-2 (1 1/4") z=39 with hub, steel is designed for 20B-2 roller chain (European standard DIN 8187 / ISO 606), double-strand (duplex), with a pitch of 31.75 mm (1 1/4"). It has 39 teeth and is made of structural steel.

The sprocket has a one-sided hub with a diameter of 150 mm, welded to the plate, and a pilot bore of Ø30 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 80 mm.

Technical data

Applications

It works well in high-power agricultural machinery, presses and feeder drives in processing plants. The double-strand version carries higher loads than a single-strand one of the same pitch.

Frequently asked questions

Which chain does the 20B-2 z=39 sprocket fit?

20B-2 roller chain to European standard DIN 8187 / ISO 606, with a pitch of 31.75 mm. A duplex sprocket requires a double-strand (duplex) 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.

Why does the sprocket have a pilot bore and how is it machined?

The pilot bore Ø30 mm is left on purpose so that it can be bored precisely to the machine shaft size. The sprocket is clamped in a lathe by the outer edge of the hub to avoid run-out, and the bore is usually machined to H7 tolerance. The maximum bore diameter depends on the hub diameter.

How is a keyway cut in the hub?

The keyway is made to DIN 6885, keeping it aligned and with the correct width and depth so that the key sits firmly. The key should fit accurately - play in the keyway accelerates wear and, under shock loads, can lead to the key shearing off.

What is the set screw hole in the hub for?

The threaded hole, usually made above the keyway or at 90° to it, takes a headless set screw. It prevents the sprocket from sliding along the shaft when the machine vibrates.

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.