Unisaw lock knob thread size

[Bill Dufour]

I have a Delta 12/14 saw which uses the same lock knobs to lock the tilt and elevation wheels in place. I have neither knob to compare. Can someone tell me what thread they are. I believe they are 5/16 NF or a slim chance of 3/8 NF. These should be the simple ones with a 60 degree point. I am not sure if the non threaded portion near the point is needed or just a convenience so they come out and go in faster.
Bil lD

[Bruce Page]

Bill, the 2 lock knobs on my 10” Unisaw are 7/16-20 UNF. I can’t imagine them being smaller on your 12/14.

[Bill Dufour]

Thanks Bruce. For some reason I have no 7/16 bolts at all so i will have to buy some 7/16-20 all thread and find out if mine is the same as yours. I will let you know what I find out. It is not 3/8 fine or 5/16 fine that I do know. Nor is it 3/8 NC or 5/16 NC.
Bill

[Bill Dufour]

Thanks again Bruce. My Grainger order came in today and it is 7/16-20. 7/16 bolts seem to be in short supply at my hardware stores. I do not think I ever used anything between 3/8 and 1/2 before. I thought the threads started down about one inch they start almost at the top of the hole. If I had known that I could have measured them somehow.
Bill D.

PS: I know the point is a 60 degree included angle on the tip. and the first 1-1.5 inches behind the tip can be turned down to the minor diameter. That reduced diameter is not required it just makes it faster to install or remove, I think.

[Andrew Seemann]

7/16 tends to be avoided because you can just get a 1/2 nut on it, but obviously it won't have the proper thread depth and can fail. In one shop that I worked in, we would throw any 7/16 away we found, to keep the engineering students from using it by accident. It does tend to show up in machinery though and Ford had a particular fondness for it back in the imperial days.

[Bruce Page]

Here are the dim's off of mine.

[Bill Dufour]

Nice diagram Bruce. Is that wingnut handle factory? I have only seen round knobs or three lobe designs.
I extended the smaller diameter neck on my per your diagram. I had made it about one inch long ,but with your numbers I extended it to about 1.65 inches. That does save a lot of time installing and removing it. Now I just have to figure out how and where to mount the knob. It is threaded clear through so I will probably use some jb weld to lock it in place. If it was simple nut I would soft solder it together but the knob has a nice factory paint job which feels a bit like rubber.
Bill D

[Bruce Page]

Yep, they're the stock knobs that came with my 1998/99 Uni.