Sprocket 12B-2 z=57 with hub, Cast iron

Product Description

Sprocket 12B-2 z=57, with cast iron hub

Sprocket 12B-2 with hub, 57 teeth, duplex - a product matched to a chain with a pitch of 19.05 mm (3/4"). The sprocket is made of grey cast iron - a traditional material for sprockets in applications with moderate loads and lower rotational speeds; the bore in the hub is a pilot bore intended to be machined to the shaft size.

Technical data

Frequently asked questions

How should a chain drive be lubricated to extend its service life?

The lubricant should get between the rollers and plates of the chain, not just onto its outer surface - it is best applied to the lower (slack) part of the chain, just before it runs onto the sprocket. In a dusty environment, a thick grease works better, while at high speeds a lower-viscosity oil that penetrates the joints more easily is preferable.

How do you select the number of teeth on the driving and driven sprockets to obtain the required ratio?

The ratio is calculated as the quotient of the number of teeth on the driven sprocket and the number of teeth on the driving sprocket. For example, to halve the rotational speed, the driven sprocket should have twice as many teeth as the driving sprocket - both sprockets must have the same pitch and number of strands.

How important is the concentricity of the hub bore relative to the toothed rim?

If the hub bore is not machined concentrically with the toothed rim, the sprocket will "run out" during operation - the teeth will engage the chain at a varying angle, which accelerates their wear and generates additional vibration. That is why boring out the pilot bore must be done on a lathe, clamping the sprocket by the hub or rim, and not "by eye".

How often should chain tension be checked on a machine in operation?

In machines operating continuously, it is advisable to check the tension every few weeks, and in a newly installed drive - as early as after the first hours of operation, when the chain "beds in". A correctly tensioned chain has a slight, visible sag on the slack side - too tight a chain accelerates bearing wear, while too loose a chain increases the risk of it jumping off the sprocket.

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.

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?

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.