A3 Woodruff Key

Our factory produces A3 Woodruff Key (crescent keys) manufactured according to GB/T 1099.1 standard, using A3 carbon steel as the material. The characteristic of half-round keys is that they can slightly sway in the key slot, fitting perfectly onto the tapered shaft. The hub can be aligned as soon as it is fitted, without the need for hammering or squeezing. They are suitable for connecting tapered shaft ends with hubs, and also for some light-load transmission applications that require automatic alignment.

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Product Description

If it's a flat key, the key slot must be machined to perfectly fit the key. Any slight inclination or machining error will prevent the hub from fitting in, requiring hammering and repair. Half-round keys are different - when the hub is fitted onto the shaft, the key automatically aligns itself according to the inclination of the bottom surface of the hub key slot, and fits in place once fitted. This is particularly useful in the connection between a conical shaft and a hub.

For general light-load transmission and positioning applications, its strength is fully adequate. If the load is heavier or there is impact, you can consider switching to 45 steel or 40Cr, which we can also produce.

Name	A3 Woodruff Key
Material	A3
Standards	GB,DIN, BSW, JIS, UNC, UNF, Non-standard, Customized Drawing
Thread	Metric Coarse, Metric Fine, UNC, UNF, BSW, BSF.
Sizes	M3-M38Metc
Finish	Plain/Black/Other
Price	0.03usd/pcs-0.50usd/pcs
MOQ	Stardard item(Usually little hundred-little thousand)/determined if non-standard

Product Feature

Being able to swing and assemble without hammering: This is the biggest difference between a half-round key and a flat key. The key can slightly swing in the circular arc slot, and when the hub is fitted, the key aligns itself, swinging according to the angle of the bottom surface of the hub slot, and fits perfectly in one go. There's no need to hammer like with a flat key if it's not aligned properly, as hammering incorrectly can damage the key or slot.

Standard configuration for conical shaft ends: The connection between the conical shaft and the hub, where the conical surface itself has a taper, makes it difficult for the rectangular cross-section of the flat key to fit the slope of the conical surface. The circular arc bottom surface of the half-round key can match the circular arc groove on the shaft, and the slightly sloped bottom surface of the key slot on the hub side can be adapted by swinging. Where conical shafts are used, the half-round key is a logical choice.