Is there really such a thing as an unneeded tool?

Posted: Mar 4, 2012

Milwaukee Diamond Sawzall Blade

World's worst blade?

About $12

I recently picked up Milwaukee's 15-amp "Super-Sawzall" for doing renovation work. So far I'm pretty impressed with it. While picking up some new blades yesterday, I saw this diamond grit sawzall blade from Milwaukee. According to the packaging, it lasts "up to 30 times as long" and can be run twice as fast as a conventional blade. Sounded like a bargain to me.

I suppose the operative phrase here would be "up to". I'm not sure what it would be cutting to last 30 times as long. Maybe butter? Balsa wood? I can tell you for sure that it sucks at cutting cast iron, even though the packaging specifically lists cast iron as a material for which this blade is well suited.

I had gone to the store specifically to get some metal-cutting blades to cut out some cast-iron porch railings. Nothing massive, the rails were only about 1/4" thick and maybe 1/2" wide. The blade began to bog down halfway through the first cut and became completely ineffective partway through the second cut.

These two photos show the result of just over a single cut in cast iron. The first shot shows the unused portion of the blade, while the second shows the part that was doing the cutting. As you can see, the blade has gone almost completely smooth. I'm not sure if the diamond grit has come off or just become completely clogged with cast iron. Regardless, it doesn't work very well.

Needless to say, I wasn't impressed. After running back to the store and grabbing some conventional metal-cutting blades, I finished the remaining 13 cuts with a single blade. I would guess that the each cut took less than 1/4 as long as that first cut with the diamond blade. Perhaps the package is a misprint, it should actually say 1/30 the life of a conventional blade?

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