On 03/07/2019 20:03, Bill Wright wrote:
On 03/07/2019 16:02, Jim K.. wrote:
Michael Chare Wrote in message:
What is the best blade to cut steel with a small maybe 4.5" angle
grinder.


1mm slitting disc.

Agreed.

Bill

+1, especially if you are just cutting clamped lengths transversely.

But if you are *cutting up* a structure you might be better off with
thicker blades that will tolerate a bit more side load. Also remember
that the structure may have internal stresses, so that a cut may start
to spring closed as you get near the end. In such cases you may actually
be better off using thick, dished grinding disks. A "grabbed" disk will
transfer a lot of force to the body of the grinder, or may cause a
smaller object to flail around. The secret is to cut through the last
bit *very* carefully, and more by grinding it away from the side rather
than just trying to go through it like a guillotine.

I once had to get a very large pipe hanger destructively dismantled, but
with some care so that I could get at the internal bearings. This
weighed at least a quarter of a ton, had built in loads of around 20
tons, and a compressed coil spring about two feet long, made out of 1
inch bar. A guy from the heavy mob took it apart with a gas axe and I
was quite worried about exciting things happening, but he knew exactly
what he was doing. He took several inches of the coil up to red heat,
and it just relaxed gently until all the strain was released.