Sprocket 20B-2 z=8 with hub, hardened

Product Description

Sprocket 20B-2 z=8, hardened hub

The sprocket 20B-2 shown is a duplex sprocket with 8 teeth, made with a hardened hub, for chain with a pitch of 1 1/4" / 31.75 mm. Sprocket compliant with DIN 8187 / ISO 606, milled from C45E steel (EN 10083-1); the teeth are induction hardened (45-55 HRC), while the core and hub remain soft, allowing the bore to be safely machined to the shaft size.

Technical data

Frequently asked questions

How does uneven tooth wear affect machine vibration?

Worn teeth cause the so-called polygon effect - the chain drops off and climbs onto the teeth abruptly, which transmits vibrations to the shafts, destroys the bearings and leads to cracking of welds in the machine.

What should be used to preserve sprockets before a longer break in operation?

After cleaning with a brush and a technical cleaner, apply preservative grease or a thick, moisture-displacing spray oil to the entire surface of the sprocket. This will protect the carbon steel against a rusty film during a break in the workshop.

When is it worth considering a sprocket made of reinforced steel for heavy-duty operating conditions?

In heavy dust, with powerful jolts (e.g. in presses) and where a breakdown in the middle of the season cannot be afforded, sprockets made of higher-strength quenched and tempered steel are often a good solution - it is worth consulting the supplier about unusual operating conditions.

Is a duplex sprocket the same as a tandem sprocket (for two single chains)?

No, even though they look very similar. A tandem sprocket is also a single, monolithic sprocket, but with a different (wider) spacing of the toothed rims - designed specifically for two independent simplex chains running in parallel. This duplex sprocket has a rim spacing matched to a single duplex chain, in which both strands are integrated with each other. Using a duplex sprocket for two single chains is a mistake - the spacing is too narrow and the chains will rub against each other, which leads to accelerated wear and, in extreme cases, to serious drive failure.

Where is this product used?

Applications include drives in the food industry, packaging machines, sorting lines and agricultural harvesting machines, where the sprocket operates seasonally but under full load.

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.