Drilling a pritchel hole in a old anvil

hi curt, i have been a practicing smith for over 50 years. as well as a tool collector. an old anvil like your mouse hole can tell a lot of stories if you know how to read it. this world is full of anvils, i hope you don't butcher that old anvil of yours and make it it's last story. have fun, mark

Reply to
Mark Finn
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I give you a lot of credit. That's a lot of work!!! You are a much better welder than I am. I draw the line at grinding the faces.

Pete Stanaitis

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Reply to
spaco

Well, there is a another harsh, crude way to get a hole started through the tough stuff. Got a stick welder? Grab some 1/8" 6011, dip them in water, and crank the amps way up. Probably give you a hardenned edge once it cools, but might be enough for you to burn through your hardfaceing bigger than it needs to be, then drill the softer material underneath the rest of the way through at size. Fill the top edge back to just undersize as you're putting your final hardfacing on the rest of the top, and tidy up with a die grinder.

They also make special burning rods, but I've not had great results with them. If you try this, you're probably better to have the anvil on its side to give the molten bits somewhere to go...

--Glenn Lyford

Reply to
Glenn Lyford

Yeah, I've got a Lincoln tombstone welder I could do that with. Good idea. If I can't cut through the hardstuff with the bits I'm going to try, I'll keep that in mind as an option. It could be a good way to locally anneal the hard face plate when I get down to it if it stops the drilling. Hum, maybe I could go buy a tig tungsten rod and use it in the Lincon with some shelding gas from my mig machine. I'll do some tests on other material first before I work on the anvil if I decide to try that route. But I'd much rather drill a clean hole through it than play with that and then have to do all the extra clean up work afterwards. I'm waiting for the bit I ordered to show up before I do anything else.

I tried one of those cutting rods once back in school just to see how it worked. Made a real mess, that's for sure, but it did cut up the piece of

3/8 plate I was experimenting with. O/A at least has the decency to burn away the extra metal. With those burning rods, it just melts and drips all over the place.
Reply to
Curt Welch

ill wil not care much about metal hardness. However,

I've used these types of drills in the past with great success. I've found you should not cool them. Use lots of speed and pressure. The theory is that the friction heats up the steel, softens it and the drill then penetrates. The tips are brazed on with a high temperature alloy, not just normal braze. The swarf comes off up to red hot. I've seen them drill bearing races and files this way.

John

Reply to
John

John wrote in alt.crafts.blacksmithing:

The amount of pressure varies with the amount of material being removed: from not too much for simply enlarging an existing hole to quite a bit to drill a large one.

I've had my best luck by drilling a small-diameter pilot hole and then using successively larger bits 'till I get what I need.

'Course, I'm one of those idjits who'll use diamond burrs on tempered steel...with results that, at least, please me.

Reply to
RAM³

I drilled a 1/4"x1/4" stick of Mo-Max steel for my lathe. I was making a form tool.

I used a solid carbide drill in my quality (1930) Delta Drill press that will hold a number 80 drill in the 1/2" chuck!

I had the steel on a solid surface and clamped into place. It drilled nicely.

The drill and the work got red - bright red hot.

Went right though. I let both cool in place by themselves. Both cooled by metal mass of the chuck or the vice. The drill was almost like new - I think a layer of vaporized metal deposited on parts of the drill. It felt sharp as before.

I made the tool and cut some brass. It worked for me.

Mart> drill wil not care much about metal hardness. However,

Reply to
Martin H. Eastburn

It's done!

Pictures here...

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Turned out to be easier than I suspected.

I week or two ago, I had tried some standard HSS drills and they were really not working. Not sure if they were dull, or if the hardfacing I had on the top layer was too hard. Probably a bit of both.

I bought a 5/16" cobalt drill from Home Depot, but hadn't tried it in the drill press because it was tricky to set up the anvil on the drill press. I tried with just a hand drill to see how it would work. It was making some progress, but didn't seem like it was really going to work.

That's when I ordered the 1/2" carbide drill and posted the questions where.

It showed up yesterday so today I got back to work on the project. Since my first attempt, I happened to have gotten an old cabinet and located it next to the drill press. That, with a 2x6, turned out to make a nice way to place the anvil on the press without having the drill press try to flip over on me. See pictures.

However, the new fancy carbide bit was too long for that configuration. So I was going to have do move the cabinet and get something else so I could lower the table and abvil a few more inches to use the long carbide bit. But before doing that, I wanted to try the other options.

First, I tried the cobalt bit again - this time in the drill press instead of by hand. Worked just fine as long as I used lots of cutting fluid. It was so easy it almost felt like I was drilling lead. But it was only 5/16 and I wanted at least 1/2" so I had to make it wider.

Next I pulled out a standard 3/8" HSS bit. This was only cutting an extra

1/16" on the hole. But it too worked fine.

I don't know if this was working because the hard plate on the anvil wasn't really very hard, or if the cobalt drill really was good enough to get though it without issue. When cutting with the cobalt drill and the followup with the HSS drill, I really didn't notice any difference at the different layers of the hole.

Next, since you guys had suggested it, I dug out a 1/2" masonry bit. It was a bit chewed up from drilling concrete. It was short enough that I could try it in the drill press configuration I had so I went ahead and tried it.

At first, it was making lots of noise, straining the drill press bearings and belt drive, and mostly just chewing up the hole edge. But I took it out and re-ground the outer edges of the tips a bit, and then it started cutting. It was still making a lot of noise, and this was really too large a job for my drill press, but it worked. Took me about 15 minutes to get all the way though.

I didn't risk trying the "let it get red hot" technique mentioned here. I kept it flooded with lots of cutting fluid. I couldn't apply the amount of pressure it really needed because the bit would just jam and slip in the chuck. So it was cutting off fine powder chips from the anvil and going very slow.

With this bit, I did notice a big difference after it got though the anvil face plate and into the soft wrought iron body. But it was still too big a hole for my drill press. It just didn't have the power to do it correctly so it was still slow going.

None the less, it made it all the way though and produced a very clean result - far cleaner than what I needed for a pritchel hole. I would have been happy with something much rougher. The hole turned out to be about .52" which was just perfect because I can easily slide a 1/2" rod into the hole to make a hold down tool out of.

Thanks for all the ideas from everyone. I'm glad I didn't have to use most of them. I never would have even thought to try that masonry bit had you guys not suggested it! It's doubt its design would cut a new hole in steel very well, but for widening a hole already cut, it sure worked for me.

Reply to
Curt Welch

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