Stanley screw sizes are a proprietary threading based on the British Whitworth before it became British Standard Whitworth.

It is NOT United Thread Standard, imperial, or metric. Thread pitch, angle, and bolt diameter are different.

I’m not sure exactly which size you need, but you have three options

1) drill out the hole and retap with the thread of your choosing. If you can get something antique, it will look better. I sometimes go to a scrap yard that sells old fasteners for $1 a pound. This is a solution if you have lots of time on your hands and don’t care if the tool becomes non-standard.

2) try and find a machinist who has old threading dies that are adjustable in imperial sizes. Modern ones are a fixed size.
While the threads aren’t UTS, they are standard pitches on different diameter stock, so instead of something like 1/4″-20tpi, the thread might be #10-20tpi or something. There are sites on the net that give the standard Stanley sizes. The difference in pitch angle (55 degree instead of 60 degree) can be ignored with adjustable dies. Whitworth dies are also available. Try somebody who works on 50’s and 60’s era British sports cars or Triumph motorcycles. I used to have some of this stuff from my high school days, but they scattered to the winds.

Here’s the real solution:

3) in the US, there are a couple ebay vendors who specialize in plane parts and are quite professional. One I go to from time to time is nhplaneparts ( http://stores.ebay.com/New-Hampshire-Plane-Parts ) I did a quick check and he does have some #66 fences, but I didn’t see the thumbscrew. Thumbscrews from other Stanley tools (Stanley #45?) might work. He would know. The best is to write and ask. He doesn’t list everything he has. You will get the correct part with this method and increase the value of your tool.

I have no connection with this vendor other than as a customer and I don’t know if he ships to Europe.<edit- ships worldwide> In the dozen or so times I’ve used him he came through. Once, he even got me a iron adjuster lever with the correct patent dates on it.

There are other vendors as well.

• This reply was modified 5 years, 7 months ago by Larry Geib.
• This reply was modified 5 years, 7 months ago by Larry Geib.

I just took a look at one and, as nearly as I can make out, it’s 10-28. It’s also brass as is the holddown itself. Stanley used the same size screw for the No.52 spokeshave lever cap (I checked.)and probably other tools as well.

Dave