Thread: Hex Shafts and Bearings
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Unread 03-10-2008, 08:12
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Re: Hex Shafts and Bearings
Quote:
Originally Posted by Cory View Post
A hex is superior to a key in pretty much every respect. You nailed one reason. No keys to lose. Another reason is that it's a pain is keys often don't fit into keyways easily, or over time the key can seize the wheel to the shaft (or sprocket or whatever you've keyed to a shaft). Keying a sprocket also introduces a major stress riser on the hub. Every sprocket failure we have ever had (and I believe the same is true for 968) occurred on the keyway of the sprocket.

Hexes mean assembly is way faster. They just slide on and off way more easily than any keyed interface I have ever used. It also is better at transmitting torque, as you have a vastly larger surface area to deliver the same amount of torque-this eliminates the stress riser associated with keyways.

If you have the ability to use hex shafts and hex broached gears/sprockets/wheels, it's an absolute no brainer, in my opinion.
I totally agree with Cory. One additional advantage is that the hex automatically centers the thing (gear, hub, sprocket) it is driving when torque is applied.

Andy B.