I was cutting 24 bars of 4" x 1/8" 6061 Aluminum today on the horizontal band saw. I was cutting the whole bundle at once so it was like cutting a 4" x 3" bar. I was talking (more like arguing) with one of the guys at the shop about the three tooth rule for bandsaw blades. He was trying to say that it didn't matter that I was cutting 24 pieces at once, what mattered was the material was only 1/8" thick and I should have minimum of three teeth in each piece of material.
I know that the bundle won't act like a single piece of stock would, the chip will break between the individual bars. But there is still the fact that the blade is passing through 3 inches of material and there has to be enough space in the gullets of the blade for the chips. A blade with less teeth will have more room for chips. My theory is to use a blade somewhere in between what would be used for one bar 1/8" thick and one bar 3" thick. I ended up using a 6-8 tpi blade and it worked good. I have also used 4-6 tpi blades with good results on this job in the past.
So what do you guys think? The three tooth rule seems to work good for cutting individual pieces, but what about cutting multiple bars?
I know that the bundle won't act like a single piece of stock would, the chip will break between the individual bars. But there is still the fact that the blade is passing through 3 inches of material and there has to be enough space in the gullets of the blade for the chips. A blade with less teeth will have more room for chips. My theory is to use a blade somewhere in between what would be used for one bar 1/8" thick and one bar 3" thick. I ended up using a 6-8 tpi blade and it worked good. I have also used 4-6 tpi blades with good results on this job in the past.
So what do you guys think? The three tooth rule seems to work good for cutting individual pieces, but what about cutting multiple bars?