Thread: Drilling a hardened steel vice

The toolmakers at one place I worked used common masonry bits that were sharpened up.
Given you have the whole bed length of the lathe to play with (no need to minimise height), have you considered making up a false table, wider than what you have so that you can clamp the vice using the side slots? (that is, no drilling?)

Michael

I hadn't considered that Michael. It's certainly an option. My only concern with that arrangement would be that it increases the overhang of the vice+workpiece from the mounting point on the cross-slide. An advantage might be that it increases the mass of the milling attachment which might reduce chatter.

Amongst the hardest things I drill are 5/16" holes through the centre of the hub/discs of nose sprocket bearings of stihl chainsaw bars. These hubs will take the point/edge of a standard HSS bit in seconds. To drill these I use a carbide masonry bits, slow (~160 rpm) speed, high pressure and lots of coolant. I touch the carbide bit up as best I can before using it and it needs a lot of pressure to bite so a drill press is essential and don't be surprised if the carbide just disintegrates before your eyes.

Thanks Bob,
My worry with a masonry bit is the interrupted cut (due to the rebates in the sides of the vice) will knock the tips off. I've got loads of masonry bits in my collection, so I'll sharpen one of them up and test it on some hard steel. According to the seller of the vice it is hardened to 58-62 HRC.

How about one of these 2 flute slot drills? Only $12 for the 8mm:
CARBIDE SLOT DRILL HRC45 - 2 FLUTE - TiAlN COATED - METRIC #G66

As far as the overhang goes, you are probably only talking about increasing it 10 or 12mm, so I wouldn't be losing sleep over it. (after all, it is only a bit of plate wider than the vertical slide so that you can get a clamp onto the vice

You could use a carbide drill, but the slightest bit of movement could kill it as they are brittle. For that to work you would need a good solid mill.
I would try the false table first - I'd rather spend money on a bit of steel that I could reuse for something else if it didn't work rather than potentially damage a drill and/or vice.

Michael

Added bonus - just looking at the photos again - a false table will give you extra clearance for the vertical table handle.

OK Michael, sounds good.
Bear with me, this is all new to me. What sort of clamp are we talking about to secure the vice to the adaptor plate?
And... is there a particular type/grade of steel plate I should be trying to track down? Something flat obviously.

jack 620
I hold my vise similar to yours by clamping into the side grooves that you will be trying to drill through. I think you will be buying trouble trying to drill down through those grooves, lots of broken drills and run of of your holes.
Bob

Hi Chris,

I did exactly what you are suggesting with an engineers vice much like yours on my vertical mill slide, for milling on my lathe (my only milling option).

Works great. I have three sets of holes in mine so I can move it up or down on the mill slide.

I just used an end mill in the drill press.

That was a long time ago, and from memory I don't think it did the end mill much good, but it worked.

It weakens the vice base a bit as you are drilling out quite a bit of metal to countersink the Allen heads, but there doesn't seem to be any issue once it's pulled up against the mill slide.

You can't use a slot mill as it won't /can't mill out the very centre section when plunging - must be an end mill

Correction: you could use a slot mill if you first drilled out the centre section of where you intend milling - ie. drill the bolt holes through first.

If I did it again I would reduce the depth of the Allen head as much as possible by machining off the top and bottom of the head . That way you won't have to countersink so heavily.

Cheers

Rob

Something this -


Michael

I'm with Michaal, though,
maybe 4 clamps?
why not a thread hole instead of a nut?
The clamps more like this maybe?

Stuart

If you're going to use clamps, why not just mill up something to fit into the slots on the side of the vice (see photo) and clamp it straight onto the millslide with the T slots?

Probably why they put the slots there in the first place.

Rob

Rob,
that is what I was starting to think. Dispense with the adaptor plate and just make a pair of extra long t-nuts that extend beyond the sides of the slotted table. Screw the "clamps" directly to the t nuts?

That, or mill up a couple of right angle narrow plates that fit the slots each side and drill through those for the Allen headed bolts into nuts in the T slots.

Sounds good to me, just make sure there is no twist when you pull them down. The only issue is whether the mill slide table is wide enough to let all this happen

That's a nice looking vice - how much $$s and where did you get it ?

Engineers vice is one very handy item.

Rob

Now I just have to work out how to mill without a mill.

I reckon I can make the t-nuts and clamps by securing the stock in my toolpost with appropriate shims. It will have to wait till Monday when I collect my 11-12mm ER40 collet from the post office. I tried holding a milling cutter in the 3 jaw and it worked its way out and stuffed the job.

Edit: Rob, I got the vice from this bloke: 63mm-2.5" QGG Screw Guide Precision Toolmarker's Vise (Free Postage) | eBay