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Metric Keyways Index page


The various pages below include dimensional and strength information for keys and splines.    It is recommended that for detailed design the relevant Bristish Standard or a reputable reference text is used.

Defination applicable to all pages

A fixed coupling is one which is an interference fit /close fitted or is guided.  A flexible spline is one which permits small misalignments < 1 degree.

Parallel Keys Taper keys Woodruff Keys Straight Sided ISO Splines Involute ISO Splines Key-spline Strength

Relevant British Standards

BS 4235-1:1972: Specification for metric keys and keyways - Parallel and taper keys
BS 4235-2:1977, ISO 3912-1977: Specification for metric keys and keyways - Woodruff keys and keyways
BS 5686:1986, ISO 14-1982: Specification for straight-sided splines for cylindrical shafts: metric nominal dimensions, tolerances and gauging requirements

BS ISO 4156:2005_1: Straight cylindrical involute splines. Metric module, side fit. Generalities
BS ISO 4156:2005_2: Straight cylindrical involute splines. Metric module, side fit. Dimensions
BS ISO 4156:2005_3: Straight cylindrical involute splines. Metric module, side fit. Inspection

Tables of old imperial keyways
BS 46 Parallel rectangular keyways...... BS 46 Square Keys...... BS 46 Rectangular Taper Keyways...... BS 46 Square Taper Keyways

Sites Providing Relevant Information
  1. Mitcalc.com...Excel based programme allowing detailed design of shaft connection (19 Eur)
  2. Tasman industires...Supplier of keys
  3. Bonut Engineering...supplier of keys
  4. Technifast Ltd...Supplier of fasteners and keys.
  5. Ondrives...Supplier of drive components including keys and splines

This Page is being developed


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Last Updated 19/01/2013