What is a “woodruff key”? I saw them at the local home improvement store but the clerk didn’t know what they were for. I found websites that sell them but none that explained how they were used.
The store also had “square keys,” which were actually rectangular. They were about an inch long and had a 1/8″-square cross-section.
Janet
Replies
A Woodruff key is flat, and half- round or crescent shaped. It is used the same a a square key, the slot in the shaft is just cut differently. Kind of like a biscuit joint. The keys on my PM saw are woodruff, and lining the pulley up right over the key is difficult from underneath.
Both keys are used for power transmission. As said before, they are just cut into the shaft differently.
A square key, has a square cross-section, it goes in a rectangular slot cut in the shaft, and mates w/ the rectangular slot in the pulley or gear.
A woodruff key does the same job, but instead of a slot in the shaft there is a semicircular cutout. In a few unusual situations this is preferable to a slot. Generally it's simply a matter of preference and what tooling you have to cut the keyway with. Square keys are much more common.
A "KEY" prevents a wheel from spinning loose on a shaft. OK?
Bohiemian
I can't picture how the key stops the wheel. Would a wooden spinning wheel have one?
Janet
I think the Bohiemian's hearing aid battery is shot he's talking really loud, maybe you should speak a little louder.(grin)
God Bless and Happy Holidays
les
http://www.jwwinco.com/technical/keyway2.htm has two pictures of the end view of a shaft and hub and how the key prevents them from rotating relative to each other.
A wooden spinning wheel probably would not be keyed to its axle, because basically all the axle does is hold the wheel in place. No power has to be delivered through the axle to the wheel like on a car.
nice to know we're all keyed in to this important discussion.
Sorry, I didn't know that keys were off-topic. They just happened to be in the same section of the hardware store as some woodworking tools.
Janet
Keys are perfectly topical. This is the Tools for Woodworking folder, and lots of woodworking machines have pulleys or other kinds of wheels keyed to shafts.
Your question is certainly more interesting than the 95th "What table saw should I buy" thread.
Edited 12/21/2002 5:00:17 PM ET by Uncle Dunc
Not off topic. WHen you get your new FWW magainze like i did today they talk about backlash in tools. Keys are a part of the cause for backlash in some powertools. So they are on topic.
They have a few illustrations that might help you understand more about what a key does, and how they work.
please no apologies, my new friend, just tryin' to be funny. emphasis on tryin'.
woodruff keys are one of the rare requests a hardware guy gets. in the 75+ year old hardware store where i got my education, knowing where the woodruff keys were was something not everybody knew, and the oldtimers, and newtimers, would be aptly appreciative that one guy in the store about them.
HAIL THE WOODRUFF KEY!
i hereby proclaim december 21st 2002 the inaugural official woodruff key day!
here's to ya fellas! merry christmas!
Imagine a "floating Tenon" concept.
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