DIN 6885 Parallel Keys
Parallel keys - sometimes called feather keys - transmit drive between a shaft and hub through their side faces, seated half in a machined shaft keyway and half in the hub. We supply them in key steel across metric sections from 4 × 4mm to 20 × 12mm in lengths to 160mm, with inch sizes to the BS 46 system alongside.
Also known as: parallel key, feather key, machine key, shaft key, key steel, bs 4235 key, bs 46 key, din 6885.
DIN 6885 (BS 4235) dimensions
| Key width | Key height |
|---|---|
| 6mm | 6mm |
| 8mm | 7mm |
| 10mm | 8mm |
| 12mm | 8mm |
| 14mm | 9mm |
| 16mm | 10mm |
| 18mm | 11mm |
| 20mm | 12mm |
Materials & strength
Three end forms
Keys are cut in three DIN 6885 forms - type A with both ends radiused, type B with both ends square, and type AB with one radiused and one square end (the British type C). Specify the form with the section and length.
Drive through the side faces
The key transmits torque through its flanks; the top face carries clearance. Fit comes from the width tolerance against the keyway, so the section size is matched to the shaft diameter in the standard.
Keyway proportions
Keyway depths in the shaft and hub are specified in the relevant standard tables alongside the key section — the split between shaft and hub keyway depths varies by key size.
Shallower sections
Alongside the standard DIN sections, shallower rectangular sections - 8 × 5, 10 × 6, 12 × 6, 14 × 6, 16 × 7, 18 × 7 and 20 × 8 - are available for shallow-keyway work.
Related specificationsWhich end form do I need?
Match the key ends to the keyway: a keyway milled with an end mill has radiused ends and takes a type A key; a keyway open at the shaft end can take a square-ended type B key. Type AB keys, with a single radiused end, cover keyways closed at one end.
What material are parallel keys made from?
Medium-carbon key steel bar, supplied self colour. Stainless steel keys are produced against requirement - send us your requirement with section, length and quantity.
How do DIN 6885, BS 4235 and BS 46 relate?
DIN 6885 and BS 4235 cover parallel keys and are closely related, although dimensional and tolerance differences may exist. Where a drawing specifies one standard specifically, send us the requirement and we can confirm the appropriate product. BS 46 is the older inch system, still referenced for maintaining existing plant.
Can I cut keys from key steel bar?
Yes - keys are routinely cut to length from bar stock in the same sections, which is the economical route when many lengths are needed.
Need DIN 6885 (BS 4235) in a non-standard size or material?
Send us your drawing — specials quoted within 24 hours.