Info needed on matching a Sheffield brace to center bits

[Fred Taylor]

I recently purchased an antique Sheffield style brace. I already had a set of center bits and assumed they would fit the brace. They don't. At least they wont insert very far and they don't lock in the bitstock. Are there different sizes of bit bases, and different sizes of square bitstocks? The button mechanism seems to work fine. Is there info out there on the web that provides historic details on this? Any info would be of help.

[Adam Maxwell]

I have a bunch of old center, gimlet, and spoon bits that have notches filed into the tang for pushbutton latches. None of them are located properly for my braces, since apparently no two braces were alike (and there's a lot of variability in tang sizes). When the fit takes me to use a plated Sheffield brace or Scotch brace, I usually just shove the bit in and rely on friction and the spring pressure to hold it. You can easily file the notches in yourself if you really want to use a Sheffield brace.

[Chuck Nickerson]

I'm not aware of a site that documents this; the variability was extreme.

If you're willing to alter the bits a file or belt sander will change the slope.
Experiment with wood pieces to get it right.
The same wood piece can get an impression of where the tab hits a fully bedded bit.
I've done this and it goes faster than it sounds.

[george wilson]

Be careful with those old wooden braces. I had one that looked perfectly o.k.. It twisted right off above the chuck. The old wood just gave up.

[Adam Maxwell]

Be careful with those old wooden braces. I had one that looked perfectly o.k.. It twisted right off above the chuck. The old wood just gave up.

Good to know! Mine also looks perfectly sound (and is brass plated), but I only use a countersink in it, since I worry about breakage. It's not as if I have a shortage of braces to choose from…this is one that I bought for its looks, including a sound lignum head.