Can't find a carbide version of this bit?

[pcguy]

Not even sure what you call this type of bit. The application is a hole about .82" in the door jam of a 70 Chevelle; read that as tight quarters. Really needs a 3/8" shaft to be able to get a drill in there. My whole punch is not up to the task.

Any help will be much appreciated.

TIA, Nick

 

[Mtndew]

Man I swear I've seen that style of tool before.
Kind of looks like a Forstner bit for woodworking but with 4 flutes,but obviously it isn't.

 

[pcguy]

That's what I thought.

The centering point is real problematic; needs a drill bit. If you make a hole that allows the teeth to reach, but not wander as hole saws have a tendency to do, it stops before you get through. Of course a larger hole makes a mess...

 

[Mtndew]

Can you use a regular hole saw?

 

[eKretz]

Or a piloted annular cutter...

 

[dcash]

"Spot Weld Removal Drill" or "Cutter"? I have several of these identical to yours, but don't remember where I got them. The better ones have a spring loaded pilot to hold center as cut progresses (works best with a small pilot hole for tip) and replaceable cutter sleeves. There are several variations including cobalt but I've never seen a carbide version (too brittle?)
Dave
Edit: On further checking there are solid carbide versions available for removing spot welds in materials like Boron Steel if you can find large enough diameter. Google "Solid carbide spot weld drill".
Hope this helps.

 

[cudafamily]

Agree with DCASH. Spot weld cutter. Just mark it out where you want it and use a carbide die grinder burr.

 

[pcguy]

Here's what I found on eBay.

Carbide Hole Cutter Drill Bit for Stainless Steel Alloy 21mm - $10 from China. Really wanted it now... Looked for one in the US, but nothing. Mid June delivery.​

Thank you for the help, Nick

 

[memphisjed]

Why carbide with a hand drill or even mag drill? Seems like you wont have the speed or rigidity for carbide with either.

hole saw. they work. if wandering is an issue swapping the drill out with a spotting drill works well.

 

[specfab]

As Memphisjed says, carbide may give as many issues as solutions. Clearly you will be hand drilling, through something like 12-ga(?) steel, maybe multiple layers. I would look for something that has less tendency to aggressively grab (and wreck the edges or corners of carbide) like a fine-tooth HSS hole saw, or a grit-edge cutter.

 

[pcguy]

My experience with HSS hole saws has not been good. I need to leave the edge of the hole with zero in the way of the ragged edges. The space to drill is lousy tight, especially on the door. Four holes in all. If I move real slowly, I may get away without melting the new paint around the hole.

 

[MrWhoopee]

Here's what I found on eBay.

Carbide Hole Cutter Drill Bit for Stainless Steel Alloy 21mm - $10 from China. Really wanted it now... Looked for one in the US, but nothing. Mid June delivery.​

Thank you for the help, Nick

I bought a set of these up to 65mm for less than $20. I've completely destroyed a couple, but they were still worth what I paid for them. Disposable tooling.

17.99US $ 37% OFF|6pcs Hss Hole Saw Set Tungsten Carbide Tip Tct Core Drill Bit Hole Saw For Metal Stainless Steel Cutter Top Quality - Drill Bit - AliExpress

Smarter Shopping, Better Living! Aliexpress.com

www.aliexpress.com

 

[CAMasochism]

Not even sure what you call this type of bit. The application is a hole about .82" in the door jam of a 70 Chevelle; read that as tight quarters. Really needs a 3/8" shaft to be able to get a drill in there. My whole punch is not up to the task.

Any help will be much appreciated.

TIA, Nick
View attachment 365474

That's not a bit. It's a wood lathe center.

 

[masheenist]

The tool in OP's picture is called a roto-bore. If using hand -held power tool,
start with a pilot hole same size as the spring loaded centering pin. Centering pin in pilot hole keeps tool from dancing off-center while cutting full size hole.

 

[gustafson]

one of those multi drills
Always thought they were a toy, but they are so much better in sheet metal than anything

 

[latheman78]

I just want to see pictures of the 1970 Chevelle.

 

[MrWhoopee]

one of those multi drills
Always thought they were a toy, but they are so much better in sheet metal than anything

^^^^This^^^^^
I'm a little embarrased that this didn't occur to me. I, too, was skeptical of step drills until I tried one. Definitely the right choice for sheet metal.

 

[Illinoyance]

I agree that is a roto-bor, made by Jancy Engineering. They don't seem to be available any longer. Jancy also made a mag drill. They were bought up by one of the big European power tool makers. Apparently their cutter line didn't survive.

 

[pcguy]

one of those multi drills
Always thought they were a toy, but they are so much better in sheet metal than anything

Have several multi-drills and none meet the 21mm dim I'm after. Since I needed to buy something... looked quickly at a multi-drill for this job...

 

[pcguy]

I just want to see pictures of the 1970 Chevelle.

The project is a restomod where the donor car was a 2014 Camaro SS with 8K on the clock; all the wiring (navigation), dash, interior, floor, consoles (upper and lower), brakes, backup sensors and camera, L99, 6L80 and on and on... were transferred to the Malibu. A seven year project at this time.

Here's a link to my 2014 Camaro SS donor to 70 Malibu restomod project:
http://www.chevelles.com/forums/showthread.php?t=794705

And a couple of pics:


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