What is the best spot weld bit or cutter that you've used ? I need to remove a bunch of sheet metal from a parts car without doing too much damage to the parts car.

i use Blair spot weld cutters. seem to last longer than the cheaper ones

I have Blair and whatever Eastwood sells, both seam to be fine. Never had an issue with either.

I use a small drill bit to start a pilot hole and then the Blair spot weld cutter.

I use this Blair spotweld cutter.No need for pre drill.

Personally, I have had better service with the drill bit style of spot weld cutter than I have with the toothed ones. I keep breaking the teeth on the toothed ones. The drill bit type are available in 8mm and 10mm. I keep both since they are cheap. And they like to be turned slooooooooowwwwww so as to not build up heat. I can use a drill bit style one for a long, long time because it doesn't have teeth to break off.

https://www.ebay.com/itm/10-mm-COBALT-SPOT-WELD-CUTTER-WELDER-DRILL-BIT/230756723524?epid=1258453770&hash=item35ba2c2b44:g:FlYAAOSwd4tT82yr

split point drill bit 5/16 and 3/8 sold at ace hardware

The Blair cutter is the hot ticket. I've used the cheapie cutters and had decent results but if you need to do more than a couple spots the things don't last so you're better off spending a bit more and saving yourself the frustration. Also get yourself a set of the panel splitters - these are hard flat blades you hammer between the panels after drilling out the spotweld to split the panels (you'll rarely drill out the weld perfectly!!)

I found the cutters break if they are able to wander. If you drill a dimple or even a hole right through the panels so the pilot stays put the cutter will work like a charm. Also keep the drill speed at a medium speed - slow enough not to heat up the cutter but fast enough that it doesn't jam in the material.

Cheap cutters will work if you keep them oiled. I fill a spray can lid with atf and dip it every two or three holes.

Stanton has a good suggestion. He's right that it is impossible to get all the spot welds completely cut, so a good amount of chiseling is necessary. I use a flat chisel blade in an air hammer that is turned down very low. Much faster (and easier) than hand hammering.

Another good reason to use the drill bit type of cutter is because they don't leave the center of the weld that has to be ground down. I can cut several panels out with just 2 bits, an 8mm and a 10mm. With the Blair toothed cutters, I would have went through quite a few of their bits. If you break even one tooth, it makes it very difficult to keep it in the cut. And it does help to pre-drill a pilot dimple for the pilot with the Blairs, but that is just more wasted time vs the drill bit style. With some odd shaped spot welds, it is still best to drill a pilot dimple even with the drill bit type. But it is only on the occasional odd spot, not every one.

When I first started pulling panels, I used the Blairs and a hand chisel. Now, with the drill bit style and the air hammer, I can pull a panel cleaner and much quicker and with less effort.

I haven't tried the split bits mentioned above. Are they hard to start and hold in the exact spot they need to be to get the most spot weld cut?

I used a wood chisel. Flatter and a longer lead on the angle. I cut right through the little sheet metal tags.

I use a punch and hammer first to make a divit in the middle of spot weld then use the cutter...

I use blair and keep the drill speed low. I never broke the teeth off one, but too much speed makes too much heat and they won't cut as well then.

any round, toothed cutter works best with reduced RPM and moderate feed rate [pressure]. this greatly reduces, or eliminates tooth breakage.
lubrication helps as well for tool life.

That Blair is the hot ticket. It is sold under a few names, including Matco. They should have the cutting tips available in 3/8" and 5/16" The blair tips are much beefier than the others that I have used. Center punch the hole, take it slow and low, keep the tip wet. .......(shhhhh. car talk is sooo dirty). As far as splitting the panels after cutting, trial and error. I had/have a homemade separator that I made from a piece of steel about 1" wide and 1/4" thick I sharpened. Eastwoods and others have a dedicated separator that mimics what I have. Take your time and don't be too aggressive with the chiseling, if you want to keep either panel in shape.

Mine are very similar to this one. Came in a 3 pack of sizes. After using the toothed ones and broke off a few teeth, bought these and never had an issue

https://www.ebay.com/itm/10-mm-COBALT-SPOT-WELD-CUTTER-WELDER-DRILL-BIT/230756723524?

The ones I own.
Ive used them several times and no complaints what so ever

https://www.ebay.com/itm/Spot-Weld-Cutter-Drill-Bit-set-HSS-1-4-5-16-3-8-USA/123130685627?

I have the Blair kit and recently purchased the drill bit style made by Norseman. Made in the USA. I bought both 8mm and 10mm. Here is the link to the 8mm cutter.

https://autobodymetalcuttingsupplie...t-point-spot-weld-cutter-made-in-the-usa


David

Thanks for all the advise. I bought a Blair kit thru my Cornwell dealer.

Same here