cutoff wheels for die grinder

The tool is a Dumore die grinder, 1/4 hp, no-load RPM 35,000.

Material is HSS or cobalt cutting bit blanks, between 3/16" and 1/2" square (or round). Mostly NOS good American stuff, some tungsten alloys mixed in there.

Places like McMaster offer a variety of wheels, the first batch of reinforced AO wheels I tried did cut some T5, but very slowly and with serious heat.

Any advise for the best cutoff wheel for this application? I'm thinking the OD should be under 1.5" and the skinnier the width the better.

Here's one candidate I have not tried: McMaster-Carr

I like the 3" wheels,I am using air tools tho,
3M makes nice thin wheels.
Gw

Honestly one of the 3m cubitron thin cut of discs in a 4.5" angle grinder works way faster and better in my experience, they cut it only slightly slower than if it was a bit of mild steel. Equally so long as you keep the pressure light they will cut for ages compared to a lot of other wheels. I ruff out most of my ground Hss tooling this way, there’s no real heat stain in the cut at all either on say cutting a 1/4" bit off, though it will still be too hot to pick up with naked pinkies!!

Theres a lot of difference in performance in cutting speeds wheel wise out there. Equally there’s a bit of a knack to getting the best out of them. My experience with the air cut offs were apart from were space dictated there use, the humble electric angle grinder was almost always easier and faster.

adama said:

Honestly one of the 3m cubitron thin cut of discs in a 4.5" angle grinder works way faster and better in my experience...

Click to expand...

+1
The Cubitron2 cutoff discs are only 1mm thick, so they cut fast and cool. I cut up some M42 rounds the other day and there was no problem. The disks last really well too - so long as you don't force them.

rwbaldwin said:

+1
The Cubitron2 cutoff discs are only 1mm thick, so they cut fast and cool. I cut up some M42 rounds the other day and there was no problem. The disks last really well too - so long as you don't force them.

Click to expand...

I take it you also are using the 4.5" wheels on an angle grinder?

I guess the bigger circumference makes for cooler running and so also longer lasting.

I don't know why I thought the die grinder would be better suited for this, guess I was thinking higher speed and easier to see the action. Ok, right angle grinder and Cubitron it is.

35,000 is pretty fast for a decent diameter cutting wheel. I think my 3 wheels max at 25000 rating. Some are less.

Dave

winger said:

35,000 is pretty fast for a decent diameter cutting wheel. I think my 3 wheels max at 25000 rating. Some are less.

Dave

Click to expand...

I thought so too, but I pulled it right off the die grinder label. It is "no load" RPMs. And the label says, as you might imagine, 1" maximum wheel size.

Dumore makes nice stuff

Sea Farmer said:

I take it you also are using the 4.5" wheels on an angle grinder?

I guess the bigger circumference makes for cooler running and so also longer lasting.

I don't know why I thought the die grinder would be better suited for this, guess I was thinking higher speed and easier to see the action. Ok, right angle grinder and Cubitron it is.

Click to expand...

We use both the 4 1/2" and 3" in 1mm.

Optimum speed for the 4 1/2" is 10000rpm (75% max speed) and 20000rpm for the 3". The smaller discs cut slightly faster.

Our main consideration is cost and depth of cut. The larger discs last so much longer.

There are also 9" discs, but they are not available in 1mm. The 9" x 1/10" seem to last forever, but they are so much slower.