The Self-Aligning Advantage of Woodruff Keys
Our woodruff keys use a semicircular, “half-moon” profile that self-aligns in the shaft keyseat and resists rocking under torsion. The curved design helps compensate for slight angular misalignment and spreads stress more evenly than straight keys, which means smoother operation and fewer surprises at speed.
Looking to round out your hardware kit for different fits and fixtures? Pair our woodruff keys with a Parallel Key for straight keyways or a Dowel Pin when you need precise locating and shear strength in mating parts.
Why Our Woodruff Keys Work So Well
A woodruff key’s geometry does the heavy lifting: the radius matches the shaft keyseat, so the key can pivot slightly during assembly and then lock under load for positive drive. That self-aligning behavior reduces fretting and improves contact where it matters, helping your pulley, gear, or coupling transmit torque without chatter. The result is confident assembly, predictable performance, and easier service when it’s time to pull things apart.
Built to Standard (DIN 6888)
Our inventory follows DIN 6888, the go-to standard for woodruff keys that specifies the semicircular form, dimensional tolerances, and fit. That means interchangeability across shafts and hubs machined to spec, consistent seating depth, and reliable torque transfer from one build to the next. Choose from common metric and inch sizes to match your keyseat and hub keyway with minimal fitting.
Materials, Sizes, and Finishes
Select from durable carbon steel for everyday power transmission or stainless options for corrosion-prone environments. We stock popular sizes across a wide range of diameters and heights, so you can match the key to your shaft and hub with the right interference and face contact. Clean edges, uniform radii, and smooth finishes help the key slide into place and stay there.
Where Woodruff Keys Shine
From small engines and power tools to pumps, gearboxes, and conveyor drives, woodruff keys keep rotating parts where they belong, locked, aligned, and efficient. They’re especially handy in applications with frequent service or small diameter shafts where a straight key can be fussy. If reliability under cyclic load is your priority, this is the key you want in the groove.
FAQs
What is a woodruff key used for?
A woodruff key locks a hub, gear, pulley, or coupling to a shaft so torque transfers without slip. Its half-moon shape self-aligns in the shaft keyseat for a secure, repeatable fit. It keeps rotating components timed, centered, and driving together.
What is the difference between a keyway and a woodruff key?
A keyway is the slot cut into the shaft or hub that accepts a key. A woodruff key is the semicircular key itself that seats in the shaft keyseat and mates with the hub keyway. In short, the key is the component; the keyway is the feature it fits into.
Is a woodruff key a fastener?
Not in the threaded sense. It’s a power-transmission element that provides positive mechanical drive between a shaft and a hub. It resists shear and prevents relative rotation rather than clamping parts together.
How to get a woodruff key out of a crankshaft?
Soak the key and keyseat with penetrating oil and let it work. Using a small punch, tap the trailing edge to rock the key upward, then lift it with pliers, avoid prying against soft surrounding surfaces. If it’s stubborn, apply gentle localized heat and repeat, taking care not to scar the shaft or keyseat.
