Cutting Metal

Cutting all kinds of ferrous metal is

easier and more accurate than ever, and these productivity gains come from a very unlikely-looking source: carbide-tooth saw blades. Offered by a handful of manufacturers, these blades look like wood blades, except they work almost as quickly chewing through steel, both thick and thin.

Advances in metallurgy and tooth design allow ferrous cutting blades to create not only very precise cuts, but sawn parts are cool enough to touch immediately after they fall off the saw. Cuts are also virtually burr-free and generated without sparks.

There are two ways you can use ferrous-cutting blades. Smaller sizes are made to fit into hand-held circular saws -- ideal for cutting steel studs, thin-gauge angle iron and small rod. But for the kind of heavier angle iron, pipe and bar stock you’ll encounter while installing larger heating and plumbing systems, the precision and productivity of a chop saw pays off. The largest ferrous blades need to spin slower than wood blades, so they must be used in designated metal-cutting chop saws only. The biggest reason why his rotational speed.

Ferrous chop saw blades are big -- typically 14 inches in diameter -- and this makes for a comparatively high tooth speed for any given RPM. Proper saws for this application max out at 1800 rpm -- about half the speed of a comparable wood saw.

Another reason ferrous blades work best in metal chop saws is the stock-holding features they have. Metal saws have built-in clamps that hold the work securely, eliminating any possibility of kickback. The best saws can also be easily adjusted for cutting angles from 0° to 45°.

Working with a ferrous blade is a much more civilized operation than using the kind of abrasive wheel chopsaws traditionally been used for stationery metal cutting. Ferrous blades cut more quickly and more quietly (though you should still wear hearing protection), And you don’t have to take the same fire precautions since they don’t generate a plume of sparks. In fact, you’ll rarely see sparks of any kind coming off a carbide ferrous-cutting blade.

You can expect hundreds of cuts from an industrial quality blade, but you can extend blade life by making each cut at the right speed. Proceed too slowly through the cut and you’ll generate excess heat that dulls teeth quicker. Cut too fast and you could chip teeth because of the strain. The ideal downward chopping speed is about half as fast as you’d go through a 2 x 6 with a wood saw. It doesn’t take long to get a feel for what’s right.

Ferrous blades lave your shop and worksite

cleaner than abrasive wheels because the size of metal filings generated is much larger. Most saws include a removable tray that catches about 80% of the stuff kicked back during each cut. This material isn’t really filings -- it’s too large to be called that -- it’s more like very coarse metal sawdust that’s bluish black in color because of the friction generated as the curls of steel were pulled off during each cut.

Whether you use ferrous cutting blades in a hand-held circ saw, a chopsaw or both, they’re one small way you can get systems installed faster and better.