Parallel keys

Keys for shaft-to-hub connections

A keyed connection transmits torque between a shaft and a component mounted on it. The key is part of the complete system: grooves, fits and hub geometry also determine compatibility. When repairing a gearbox or replacing a drive wheel, read the designation in the machine documentation and compare it with the product parameters.

DIN 6885 keys, DIN 6888 keys and DIN 6880 key stock

• DIN 6885 parallel keys — select width, height, length and end shape to suit the keyway. A rectangular cross-section alone is insufficient to identify the version.
• DIN 6888 Woodruff keys — have the shape of part of a disc and require a corresponding keyseat in the shaft. Selection is based on dimensions and the connection drawing.
• DIN 6880 key stock in 1 m lengths — for preparing components of the required length. Before buying, check the cross-section, sales unit and machining needed to obtain the finished key.

How to select a key for machine repair?

Prepare the standard or drawing, nominal dimensions, required material and quantity. For a parallel key, the starting point is width × height × length. For a Woodruff key, check all dimensions given on the product data sheet. Pay attention to the mating surface condition: a new key does not remove wear in the shaft or hub keyway.

Load, torque and operating conditions must be taken into account when designing the complete connection. Changing key size requires compatibility with the design — a larger component does not automatically solve a clearance problem. When replacing parts in an existing machine, follow the manufacturer’s documentation.

Frequently asked questions about keys

Can a parallel key be replaced by a Woodruff key?

Not without checking and appropriately changing the design. The two types require different keyway geometries, so they are not interchangeable solely on the basis of similar width.

Is measuring a worn key sufficient?

Measurement helps identify the part, but a worn component may differ from nominal dimensions. Compare the result with the documentation and the dimensions and condition of the keyways.

Is a 1 m length ready for installation?

Metre-length stock must be prepared to the dimensions of the specific connection. Check the required length, end shape and finish after machining.

Keys — NERON Piła

NERON at ul. Wybickiego 17 in Piła accepts enquiries for keys for machinery, drives and servicing. Provide the standard, dimensions, material and quantity to establish the appropriate version and availability. Other assembly components can be found in the fasteners section.