Cutting 1/4" galvanized checker plate

[tiredoldironworker]

Hello all, due to a structural engineer and his detailer being idiots, we now have to crosscut 200 lineal feet of checker plate that they messed up on. We have ordered the Milwaukee corded 8" metal specific saw and a couple of steel cutting blades. We bought a Diablo steel cutting blade yesterday to put in a new DeWalt 7&1/4" circular saw and I was able to cut 55 feet before it gave up its carbide teeth. Hopefully we will get better performance from the Milwaukee setup. Does anyone have suggestions about best practices and procedures?

 

[GeoBruin]

Hello all, due to a structural engineer and his detailer being idiots, we now have to crosscut 200 lineal feet of checker plate that they messed up on. We have ordered the Milwaukee corded 8" metal specific saw and a couple of steel cutting blades. We bought a Diablo steel cutting blade yesterday to put in a new DeWalt 7&1/4" circular saw and I was able to cut 55 feet before it gave up its carbide teeth. Hopefully we will get better performance from the Milwaukee setup. Does anyone have suggestions about best practices and procedures?

The Milwaukee will make short work of it. I have the cordless version and it's a beast. I suggest you keep the feed rate high, as in push the saw into the work rather than just letting it spin and build up heat. Also, and this probably goes without saying, but try to cut straight and don't let the blade bind up. It's bad for the blade in wood but it's even worse in metal.

 

[TurnipTruck]

The saw booklet lists feed rates and duty cycle for best blade life.
I got forty feet of 1/4” cut before my Milwaukee teeth came off. Then I read the manual.

 

[dnschmidt]

Why not use a plasma cutter?

 

[speed bump]

At 55 ft on the first blade I would probably grab 3 more and call it good.

We have the Milwaukee 8" saw and it's great for cutting grate and thin plate, occasionally someone will spray some cutting oil when they use it but generally they just let it eat.

 

[speed bump]

Why not use a plasma cutter?

It will burn the adjacent galvanizing and is less of a clean cut than a saw blade.

 

[tarbellb]

8" Milky has a cut rate chart, iirc it's 30-40% duty cycle or rather ft per min

In my experience that saw eats blades, especially anything thicker then 1/8"

Buy extra blades, once they're toast the cut will start to (significantly) wonder and take much longer

 

[MJD1]

The Milwaukee blades last the longest in my experience. Use a strait edge guide to keep the blade from twisting and keep the depth of cut so less than half of the cutting edge on a tooth protrudes thru the material.

 

[GeoBruin]

8" Milky has a cut rate chart, iirc it's 30-40% duty cycle or rather ft per min

The cut chart with duty cycles begins at 3/8" thick. You would have to extrapolate.

 

[Steve_P]

Has anyone used the Makita 7-1/4 blades for cutting steel and compared them to other brands? They're ~2X as much $ as Diablo, but they look "purpose designed" for metal, while the Diablo looks like a blade for wood. I have the Makita metal cutting saw, but I'm still on the first blade; I'm typically not cutting many feet at a time where I'd be able to say it lasted for X feet and do my own comparison.

Makita

Makita A-93837 7-1/4-Inch 48-Teeth Carbide Metal Cutting Blade, Silver - Circular Saw Blades - Amazon.com

Makita A-93837 7-1/4-Inch 48-Teeth Carbide Metal Cutting Blade, Silver - Circular Saw Blades - Amazon.com

www.amazon.com

Diablo

Diablo Steel Demon Cermet II Saw Blade with Triple Chip Grind and Perma-Shield Coating - Ideal for Medium Metal Cutting - 7-1/4" Diameter, 48 TCG Teeth - D0748CF - Amazon.com

Diablo Steel Demon Cermet II Saw Blade with Triple Chip Grind and Perma-Shield Coating - Ideal for Medium Metal Cutting - 7-1/4" Diameter, 48 TCG Teeth - D0748CF - Amazon.com

www.amazon.com

 

[tarbellb]

From my usage the Diablo out performed the (USA) Milwaukee branded blade in my M18 Metal circ

The Milwaukee form factor is similar to the Makita? I typically think Makita puts out good stuff, and don't doubt it's a solid blade and worth testing.

But, I find that any of these carbide tipped metal cutting blades are not long for this world and very much a consumable. ROI might not be there.

 

[tiredoldironworker]

We don't have access to compressed air for a plasma cutter in this rooftop situation. The cuts need to be as straight and as clean as possible. We have to weld the forty or so 5'x8' sheets edges completely all around. This is for a glycol containment tank backup system on the roof of a 60,000 sq ft chiller for a pork sausage processing facility. My boss had already ordered the Milwaukee saw before I cut the first eleven sheets. I was absolutely covered in small hot chips from the DeWalt. Hopefully the chip containment on the Milwaukee will help.

 

[PCustoms]

We have to weld the forty or so 5'x8' sheets edges completely all around.

What's your process/ppe for welding that much galvanized sheet?

 

[danielbuck]

55 feet out of 200? You're 1/4 the way there, I'd just buy a few more blades and finish. But having a saw that is spinning at the correct speed will probably be better in the end, and you'll have it for next time too

 

[tiredoldironworker]

7018 stick, forced air hoods, and big fans.

 

[Sumboodie]

The Diablo blades have massively sucked in my dry cut saws.

 

[seber]

Are the teeth coming off or just getting dull? If they are coming off, change blades before they get hot. Sharpening carbide tooth blades is easy. Just make a sliding jig and sharpen with an abrasive blade in a table saw.

 

[tiredoldironworker]

They are breaking off near the weld. The galvanizing seems very hard on them. Hope to have better results tomorrow with the 8" Milwaukee. Blades don't seem to be getting very hot and I am pushing them fairly hard. Cut depth is one tooth below the plate and I am using a 3x3 heavy angle as a rip guide. It's still hard work!

 

[MJD1]

They are breaking off near the weld. The galvanizing seems very hard on them. Hope to have better results tomorrow with the 8" Milwaukee. Blades don't seem to be getting very hot and I am pushing them fairly hard. Cut depth is one tooth below the plate and I am using a 3x3 heavy angle as a rip guide. It's still hard work!

Decrease your cutting depth some and your blade life will increase

 

[NUTTSGT]

I missed the galvanized at first. For some reason I thought aluminum

If you got 55' out of the first one, I'd probably keep with that method.


When you're done, take one of the blades, paint it gold, mount it to a nice plaque and give it to the Structural Engineer along with a tag that says "Measure Twice, Cut Once."