Hand cranks VH57 black

Hand crank VH57 is a series of hand cranks in glass fiber reinforced thermoplastic for operating spindles, adjusting screws and feed shafts. The handle turns and rotates freely around its own axis; that sounds like a detail, but it is the difference between a crank you can spin for hours and one that wears on wrist and palm with every turn. The series comes from a Swedish maker of machine elements and is used widely in the engineering industry.

The series covers eight versions. The crank dimension E comes in five sizes from 65 to 185 mm, and the hub is supplied either with a threaded hole in M8 or M10 or with a plain hole in 8 or 10 mm. The other dimensions of the cranks grow in proportion with the size, so grip and hub stay in reasonable relation to the force to be transmitted. All versions are matte black, and you pick the version straight on the product page.

The glass fiber reinforcement makes a mechanical difference. An unreinforced thermoplastic springs and creeps under load; with glass fiber in the body the crank arm gets stiff enough to transmit torque without feeling rubbery, and it keeps its shape even when the load is uneven. The fasteners are in zinc plated steel. The predrilled hole is hidden by a cover cap in light gray thermoplastic, so the finished crank has a closed surface that is easy to wipe. Matte black also hides finger marks and workshop dirt better than glossy versions.

The choice between a threaded and a plain hub hole is governed by how the crank is to sit. The threaded version screws straight onto a threaded shaft end or stud; the plain version slides onto a plain shaft and is locked with a pin or a screw joint, for example. Threaded hubs also make field replacement easier: old crank off, new one on, done. Look at what is already on the machine before you choose, since changing the mounting type is rarely worth the trouble.

The size is chosen by torque and space. A longer crank arm lowers the hand force but calls for a larger free swept area. The smaller sizes of 65 and 80 mm suit small actuators and tool adjustments, while 140 and 185 mm belong on feed screws, lift tables and adjustable conveyors where the leverage is needed. Think about the speed as well; if the crank is to be spun many turns in a row, the rotating handle and a sensible arm length mean more than maximum leverage. And on a machine with several cranks it is both neat and practical to stay within the same series, since the feel in the hand is then the same at every station.

Crank or handwheel? A handwheel gives fine control during continuous adjustment, while a crank moves many turns quickly. If there is a scale or a dial on the shaft, the crank is often the right choice, since the operator counts turns rather than feels for resistance anyway.

Plastic cranks have a couple of practical advantages over cast iron and steel: they do not rust, they weigh less and they do not feel ice cold to grab on a winter morning in an unheated hall. In settings close to food it is also appreciated that the surface is closed and easy to keep clean. We see VH57 on machine tools, packaging machines, test benches, agricultural implements and special machines built in short runs.

The cranks are supplied in packs of 5 pieces; the largest size of 185 mm comes in packs of 2. If you need a crank that must not stick out into a walkway, there is the sister model VH571 with a folding handle.

Would you like the data sheet with all the dimensions? Call us directly.