Any rule-of-thumb for replacing 4.5" cutoff wheels?

newbury · Mar 30, 2021

I've read of them shattering and I'm apprehensive of getting shards in my body even though I wear PPE.
But presently the roofing metal I'm cutting is eating about 1 Dewalt DW8062 wheel per panel width.

sea2summit · Mar 30, 2021

I cut roofing metal with my skilsaw, way faster, easier and I think safer. I dedicate my old blades to that task. But when I use a grinder I go until I can't cut all the way through a channel of the roofing then swap out so probably ~40% smaller when I'm done?

/pine · Mar 30, 2021

Something's wrong...you should be able to cut most roofing metal all day long with the same wheel...!

Snobdds · Mar 30, 2021

Don't buy harbor freight cutting wheels...stick with diablo or dewalt.

newbury · Mar 30, 2021

Snobdds said:
Don't buy harbor freight cutting wheels...stick with diablo or dewalt.

newbury said:
1 Dewalt DW8062

I agree.
Maybe I got a bad batch.

Birdhunter1 · Mar 30, 2021

If you are using it to cut look for one of those Diablo or Lenox diamond metal cutting blades. On 1/4" steel they don't cut as fast as an abrasive cutting wheel but they last 1000times longer.

herm0016 · Mar 30, 2021

get a blade for steel for your circ saw.

Deere Dude · Mar 30, 2021

newbury said:
I've read of them shattering and I'm apprehensive of getting shards in my body even though I wear PPE.
But presently the roofing metal I'm cutting is eating about 1 Dewalt DW8062 wheel per panel width.

That sounds about right in my experience. Cutoff discs don't last long but are cheap. I recently cut about 20-30 8" I beams with a stack of these. Just need to go slow and no twisting. There are maybe better options as noted by others but I have about 50 more to go through and they work. Just keep a wrench handy.

KennyG · Mar 30, 2021

For roofing, use a circular saw with a metal cutting blade. The grinder will heat the metal too much and be more likely to cause rust issues in the future. I made all the cuts necessary for my pole barn with one metal cutting blade and it's still in good shape.

TractorGuy · Mar 30, 2021

Never use them without wearing protective gear and clothing.

When I use abrasive cut off wheels I have a face shield, leather arm covers, leather apron, and leather gloves on.

I use the 4-1/2" discs until they wear down to the grinder head.

I have had a few come apart. If I see a nic in the edge I throw it away. I had a 7" disc explode on my chop saw and shatter the guard. One piece actually hit my face shield. 99% of the time they wear evenly until they are worn out.

pmsmechanic · Mar 30, 2021

I used to cut roofing metal with a skill saw with a backwards blade. It worked ok but was quite noisy and left a poor finish. My buddy says to me why aren't you using a good pair of scissor type tin snips? Why indeed? I'll never go back to grinding or a skill saw. Tin snips are quick and easy to use and.... quiet.

Industrial Toys · Mar 31, 2021

Most (if not all) violent failures I have experienced were precipitated by catching the wheel on something and taking a chunk out of it. Then you better look out!

oosik · Mar 31, 2021

Long ago I worked at a facility where the Ingersol-Rand tools used 6" cutting wheels. Infrequently - one would fragment. Never knew why. Everybody blamed it on improper use of the tool. Leather gloves, long sleeved shirts and heavy duty plexiglass face shields were the word of the day.

Most wore leather welding jackets when using these cutters.

triptester · Mar 31, 2021

When using cutoff wheels I found that they don't work well if you try to use them like a saw, where you cut all the way thru as you move forward. When cuts of more than a few inches need to be made I place a metal straight edge where a line is scored. Then with light pressure and moving back and forth grind thru. With this method making a 4 foot cut thru 3/16" diamond plate takes one 4 1/2" cutoff wheel.

PILOON · Mar 31, 2021

herm0016 said:
get a blade for steel for your circ saw.

Yep!
I found such a blade (rare) that looks like a standard saw blade but has no teeth, just a lot of slits.
The call it a 'friction blade'.
I've made a whole lots of roofing cuts and that blade is still good to go.
Downside is it creates a lot of 'steel wool' like remnants as well as leaving a scorched (1/8") like trace on the cut metal.
OK for thin (roof like) metal but not for thicker stock.