View Full Version : Fitting mill vice keys?

10-13-2009, 01:14 PM
The keys on the bottom of my new mill vice are about 0.050 wider than the 5/8 slots in the mill table. What is the best procedure to cut and fit these?

10-13-2009, 01:28 PM
Install the vise without them and mill them in the vise.
Some questions:
Are your T-slots parallel to the dovetails??
Are the keyways in your vise parallel to the fixed jaw??

Or you could put them in the "miscellaneous" drawer of your toolbox and forget about them.
Unless you have a huge mill, the vise keys are seldom necessary.
I do cock my vise sometimes, (I don't like swivel bases), and for that you do not want them.


10-13-2009, 01:30 PM
Make a set of step keys.

10-13-2009, 01:38 PM
Brilliant! Why didn't I think of that.


Frank Ford
10-13-2009, 03:09 PM
Here's a trick I used to make certain the vise key slots were in alignment with the jaws:


I stood the vise on its nose and had it bite a piece of stock that was a precise fit in the T-slot before I milled the slots for the keys.

Here's the full process:


10-13-2009, 03:18 PM
I've got my vice on a plate with special oversize pins I made that just fit in the table slots, which gets it repeatably pretty close.

But I still like to put indicator on it to tap it in before a final tightening down.

This is fast to do because I'm using one of the pretty amazing Noga indicator holders. This is one of the best well designed and well made mechanical devices I've ever used, its rediculously easy to get the indicator oriented on the vice jaw.

Here's the one I'm using, I just let the magnet grab on the quill:


Paul T.

10-13-2009, 03:22 PM
The keys are allready there. They are 0.050 wider than the 0.625 slots.

I was curious about:
1. How much undersized the step was cut to allow for alineing the vice.
2. Do I need to take them out or could I mount a plate in the old vice and clamp the new vice upside down on the plate and cut the step. Seems to me that that would assure that the cut surface was parallel to the back jaw surface.
3. would you cut the back face or the front face of the key?

Rich Carlstedt
10-13-2009, 06:04 PM
If you have an adjustable parrallel, you can place it in the keyway of the table and measure it, or cut a aluminum test key and use it for actual dimensional width of the table keyways.
On older mills, several measurements need to be taken as T nuts cause a distorted width over time.

1.Flip the vise over with keys already attached
2. BE SURE the vice handle is towards the mill column!
(This eliminates "anglar error" if the table keyways are not parrallel to the table ways, and is very important)
3. Remove material on both sides of the keys (!)for maximum accuracy
4. Mill keys to -.001 of keyway size.
Be sure to cut both keys in front and back with mill cutter going in same direction ( climb or conventional ) and without moving Y axis during each pass.
Take the jaws off and clean all surfaces , and mike the jaws to be sure that they are also parallel ! Replace them on Vice before milling keys if OK
After Milling, make a habit of always keeping mounting surfaces clean.
"adjustment clearance" is not needed with above procedure.


10-14-2009, 03:58 AM
Sheesh, climb milling, non climb, front back adjust left right up down??????

The Austrians that designed the extras for my machining centre (Maxi-Mat V10) really screwed up. They used round pins as the location guides in my tee slots.

Sadly it requires that the holes they are pushed into are accurately machined in the baseplate of whatever they are in.

Are these the original Round Tuits?? :rolleyes:

Regards Ian.

10-14-2009, 02:08 PM
Don't assume the slots in your vise are parallel to the jaws on top. Put a bar in the mill slot like Frank did and clamp the vise upside down on it and clamp it to the table. Then machine the keys in the base of the vise to have about .001-.002" clearance to fit the slots. Now they should fit in the slots and be parallel to the table slots.

If the keys are loose in the table slots then push the vise toward the rear and clamp it down and it will be aligned.