Metal Cutting Circular Saw Blades

[Wamsutta]

The Diablo doesn't seem to be lasting very long. They work great when they're new but after a few hours of use, some of the teeth break off. And I'm not abusing them either. I go real slow with the saw so that I can follow my cut line. The material is just mild steel. Nothing hardened or tempered. I wouldn't complain except they're about $40 a pop after you factor in sales tax. I'm running this thread to see what kind of experience you guys have had with metal cutting blades and which brand works best for you.

 

[Dakotadadv8]

Angle grinder cuts metal well.

 

[GeoBruin]

Angle grinder cuts metal well.

Not compared to a TCT blade in an appropriate saw. By comparison, a grinder doesn't really cut but rather just wears the metal away while generating a ton of heat.

Abrasives have their place but for making straight cuts with a good finish a good saw with a TCT blade is the ticket.

For the OP, I have to ask, is the saw you're using really a metal cutting circular saw? As in, is the speed really appropriate for the blade? Running a metal cutting balde at too high a speed would definitely result in premature wear.

 

[Dakotadadv8]

May need to add a metal cutting saw Makita just in case.

 

[KnurledNut]

Not compared to a TCT blade in an appropriate saw. By comparison, a grinder doesn't really cut but rather just wears the metal away while generating a ton of heat.

Abrasives have their place but for making straight cuts with a good finish a good saw with a TCT blade is the ticket.

For the OP, I have to ask, is the saw you're using really a metal cutting circular saw? As in, is the speed really appropriate for the blade? Running a metal cutting balde at too high a speed would definitely result in premature wear.

Cermet > TCT

 

[dnschmidt]

If you're using this on a high speed woodworking table saw what you see is what you get. These should be used on the saws specifically made for cutting metal. I have both the small and the large Milwaukee metal cutting circular saws and I've not experienced these problems. These are a ******** solution to people that aren't willing to spend the money for the correct tool which is in fact a 14" dry cut saw. They will work if you use them only sporadically but not for any length of time.

 

[KnurledNut]

This is one of the few applications where the older brushed cordless circular saws outshine their BL predecessors. Without buying into dedicated MC saws. Slower RPM’s. I keep an old Makita 18v LI mated with a metal blade just for this purpose.

 

[KnurledNut]

Have a 6370 at work. Highly recommend the Milwaukee cermet blades.

 

[Wamsutta]

For the OP, I have to ask, is the saw you're using really a metal cutting circular saw? As in, is the speed really appropriate for the blade? Running a metal cutting balde at too high a speed would definitely result in premature wear.

I have the Diablo metal cutting blade on a worm drive Skilsaw. The R.P.M. is 4600/no load. The blade works flawlessly when it's new. I don't know exactly how much total cutting time I have on the blades when they fail. It can't be very much because I just use it in my backyard to cut scrap metal for my welding hobby. How much time would you expect to get out of the blade if you were using it to cut soft mild steel? Most of the steel I cut is 1/8 thick.

 

[nadogail]

I have a 12" Craftsman Commercial Direct Drive Floor Saw, it was purchased 2nd hand from a bankrupt contractor in the late 70's. The Carbide toothed blade has occasionally cut 1/8" mild steel with no apparent ill effects.

 

[uart]

I have the Diablo metal cutting blade on a worm drive Skilsaw. The R.P.M. is 4600/no load.

That's over 2500 m/min (8500 ft/min) cutting speed on a 7.25 inch disc. I think that's a lot more than most blades are rated for when cutting steel.

 

[Walkers]

I have the Diablo metal cutting blade on a worm drive Skilsaw. The R.P.M. is 4600/no load. The blade works flawlessly when it's new. I don't know exactly how much total cutting time I have on the blades when they fail. It can't be very much because I just use it in my backyard to cut scrap metal for my welding hobby. How much time would you expect to get out of the blade if you were using it to cut soft mild steel? Most of the steel I cut is 1/8 thick.

You are using the wrong saw and cheap blades. It is not a combination known for longevity. Buy the Milwaukee saw and the cheap Diablo blades will last longer. I like the Milwaukee blades, they are a good balance between cost and endurance.

 

[Wamsutta]

That's over 2500 m/min (8500 ft/min) cutting speed on a 7.25 inch disc. I think that's a lot more than most blades are rated for when cutting steel.

It might be 4600 ft/min. This is what it says on its nameplate:

SKILSAW HD77M
7-1/4’’ (184mm) Worm Drive Saw F012HM7700
120V 60Hz 13A no load speed 4600/min
SN 78315 HH344112
Assembled in USA

 

[rmack898]

I’ve used both the Milwaukee and Diablo with good results.
The thing that will destroy a blade fast is any side loading. If you clamp a fence to the work and keep the saw tight to the fence, the blade will last much longer.

 

[Steve_P]

4600/min is 4600 RPM. This is below the Diablo carbide blade maximum as they're intended to be used on a typical 5800 RPM circular saw.

 

[mike93lx]

It might be 4600 ft/min. This is what it says on its nameplate:

SKILSAW HD77M
7-1/4’’ (184mm) Worm Drive Saw F012HM7700
120V 60Hz 13A no load speed 4600/min
SN 78315 HH344112
Assembled in USA

A rating like that on a tool will essentially always be rpm. Fpm depends on the actual diameter of the blade in use, which can vary

 

[Wamsutta]

I’ve used both the Milwaukee and Diablo with good results.
The thing that will destroy a blade fast is any side loading. If you clamp a fence to the work and keep the saw tight to the fence, the blade will last much longer.

I think you're right about that. I have noticed that when the blade gets trashed, it's always after a long rip cut with no fence.

I've been ripping narrow strips that are 1-1/2 inches wide. The clamps get in the way of the saw's path, so what I have to do is screw the material down to the bench and countersink the holes for the screws so that the saw can glide over the screw heads. Often times the edge of the material is screwed down to the edge of the bench. Not a very solid arrangement for making a cut, but like I said I can't use clamps because the saw will run into them.

I've been using the saw's rip guide along the outer edge of the material, but it's not as secure and accurate as using a fence.

 

[GeoBruin]

I think you're right about that. I have noticed that when the blade gets trashed, it's always after a long rip cut with no fence.

I've been ripping narrow strips that are 1-1/2 inches wide. The clamps get in the way of the saw's path, so what I have to do is screw the material down to the bench and countersink the holes for the screws so that the saw can glide over the screw heads. Often times the edge of the material is screwed down to the edge of the bench. Not a very solid arrangement for making a cut, but like I said I can't use clamps because the saw will run into them.

I've been using the saw's rip guide along the outer edge of the material, but it's not as secure and accurate as using a fence.

I bought a cheap universal track saw sled and track system and slightly modified the sled to work with my metal cutting circular saw. It makes long, straight cuts a breeze.

 

[TurnipTruck]

The manual for my Milwaukee steel-specific circular saw specifies something like 30” of cut per hour.
Before I knew that, a single 8’ cut of 1/4” plate all at once pretty much took all but three teeth off.

 

[Wamsutta]

^
8 feet of 1/4 inch steel plate in one cut?

 

[Steve_P]

The manual for my Milwaukee steel-specific circular saw specifies something like 30” of cut per hour.
Before I knew that, a single 8’ cut of 1/4” plate all at once pretty much took all but three teeth off.

That is insanely slow, and I think would be nearly impossible to actually accomplish

But, I have a Morse Metal Devil? carbide blade metal chop saw, and the slower I go, the better it cuts. You definitely can't push it like you can an abrasive wheel.

So, I guess the answers are to go slow, and get some sort of a guide, preferably a track, no matter what carbide tip blade saw you're using on steel.

 

[TurnipTruck]

Rather than relying on my synapses firing correctly, here is an excerpt for my Milwaukee metal saw:

It took me 3 intervals of cut/cool to get across a 30” cut in 5/8“ steel, but I didn’t lose any teeth from a $75 blade this time.

 

[KnurledNut]

Last thick cut I did was 5/8 plate. Around 4’ in one go without stopping.
The blade was already missing about 1/3 of its teeth. Completed the cut without issue.

 

[dnschmidt]

This kind of cutting is what plasma cutters are made for. Acetylene torches work well too.

 

[Steve_P]

This kind of cutting is what plasma cutters are made for. Acetylene torches work well too.

Sure, if you can live with the crude edge quality. I'd never accept something like that for a part I designed at work, and would always demand a machined edge; obviously, this is beyond what most people can do in a home shop. But if I was going to build a new welding table for myself, and got the rough size of the plate torch cut, I'd still cut the edge with a saw, even if it cost me a $40 blade. To me, it's worth it for something like a welding table that you are going to look at for decades.

 

[dnschmidt]

Sure, if you can live with the crude edge quality. I'd never accept something like that for a part I designed at work, and would always demand a machined edge; obviously, this is beyond what most people can do in a home shop. But if I was going to build a new welding table for myself, and got the rough size of the plate torch cut, I'd still cut the edge with a saw, even if it cost me a $40 blade. To me, it's worth it for something like a welding table that you are going to look at for decades.

Ever hear of a grinder? A nice flap disc leaves a better surface than any saw.

 

[GeoBruin]

Ever hear of a grinder? A nice flap disc leaves a better surface than any saw.

Sorry Denny, I get what you're trying to say, but you simply cannot compare a cut made with a torch or a plasma cutter and finished with a flap wheel to one made by a saw with a TCT blade. The cut edge is straight, square, and has nearly a mirror finish, all with relatively little skill or effort required.

I have and use my OA torch a lot, and I have a Hypertherm Powermax 45xp, but I wouldn't consider using either to cut a long straight edge (even if I had a track setup!) as long as I have a metal cutting circular saw in the shop. Maybe if I had a long cnc plasma table, but even then just maybe...

 

[dogdog]

Talking about these dry cut blades . Got a HF one last weekend, it is advertised as cement carbide 66 teeth for steel and stainless 14” looks a lot beefier than the MK or junk 90 tooth evolution blade I got

 

[GeoBruin]

Talking about these dry cut blades . Got a HF one last weekend, it is advertised as cement carbide 66 teeth for steel and stainless 14” looks a lot beefier than the MK or junk 90 tooth evolution blade I got

I realize it may be an autocorrect thing but I think you meant cermet carbide. Cermet is a portmanteau of ceramic and metal.

 

[dogdog]

I realize it may be an autocorrect thing but I think you meant cermet carbide. Cermet is a portmanteau of ceramic and metal.

Yes going to used it to cut some 4” cast iron pipe later and see how it works. The 90teeth evolution blade was terrible

 

[seber]

I get excellent results with a 7 1/4" abrasive blade in a gear drive Skilsaw. The cut looks just like that made by a metal cutting toothed blade. They wear down but are so much cheaper the cost is probably similar.

 

[mike93lx]

I get excellent results with a 7 1/4" abrasive blade in a gear drive Skilsaw. The cut looks just like that made by a metal cutting toothed blade. They wear down but are so much cheaper the cost is probably similar.

I can't imagine what the inside of that saw looks like

 

[seber]

I can't imagine what the inside of that saw looks like

I've been using it for this purpose for about twenty years. As I recall, I think I paid $20 for it at auction so I'm not too worried about it.

 

[mike93lx]

I've been using it for this purpose for about twenty years. As I recall, I think I paid $20 for it at auction so I'm not too worried about it.

Hey, it's a tool, made to be used. Sometimes the way as designed, sometimes not. No judgement here. Send it!

 

[GaryM909]

I get excellent results with a 7 1/4" abrasive blade in a gear drive Skilsaw. The cut looks just like that made by a metal cutting toothed blade. They wear down but are so much cheaper the cost is probably similar.

I have done the same back in the eighties. It made a nice square cut on thin wall stainless.

Up until last year I had a Milwaukee metal saw that I used in the field. I preferred the Milwaukee blades.
When I retired I sold the saw because I didn't like using it in my garage. I always ended up with small metal chips everywhere. I just use 6" zip discs on most stuff with a cordless Dewalt or corded Makita but sometimes I use 9" zip with a corded Makita.
I sweep up the floor and bag the dust before I put it in the garbage bin and then use a leaf blower to blast the rest out in the alley.

 

[Richard D]

I went through a couple 14” abrasive chop saws before I finally got a dry cut saw. Night and day difference. Sometimes I use a little coolant even though it’s not required, probably makes the blades last longer. Wasn’t an extremely expensive tool about four bills. Morse Metal Devil.

 

[Richard D]

Got mine in 2015.

https://www.amazon.com/gp/aw/d/B000IHXOKI?psc=1&ref=ppx_pop_mob_b_asin_title

 

[mike93lx]

Got mine in 2015.

https://www.amazon.com/gp/aw/d/B000IHXOKI?psc=1&ref=ppx_pop_mob_b_asin_title

And there's even an open box available for $350. I don't have a need, but I'd probably be jumping on that if I did

 

[Richard D]

I haven't been using mine all day every day for 9 years(although during some projects it got steady usage, and even abuse from a 400 lb weldor) but for a hobbyist I think it would last a lifetime.

 

[Steve_P]

I also have the Metal Devil, and it's nice tool for a hobbyist. But you can't cut hardened steel with it, so I still have my abrasive chop saw. And both the metal devil and the abrasive chop saw are useless to cut sheet steel, which is the OP's concern.