K

Keyway:: On a shaft a keyway is a linear external machined slot which will contain usually half the depth and the full length of the key. Inside the coupling or other shaft-fitting fixture an internal keyway will contain the other half of the key. When the three are properly assembled, neither the shaft nor the fixture can rotate without the other turning round-for-round also.

The key to the left is only partly inserted into the shaft keyway. The key on the right is fully inserted. This shows an overhead and a profile view on the same shaft, although two keys on the same shaft will usually be in axial alignment with each the other.
Knob fitting:: In alignment this would usually pertain to dial indicator jigs and other such paraphernalia normally part of an indicator set. Knob fittings, sometimes called knurled fittings, are the norm rather than the exception.
Knurled fittings:: See knob fitting.

< Previous Excerpt

A Millwrights Guide to Motor/Pump Alignment, Second Edition