I am currently using a Northern Industrial 4.5" x6" 3/4hp bad saw to cut 6061-T6 aluminum plate and extrusion.

Blades
64.5 x .5 size
Raker style 14 TPI and 10 TPI

Brands
Irwin
Starrett
Northern Industrial
Enco

The problem I am having is that the blades break long before the cutting edge gets dull. A crack develops in the chip gullet of the blade and then gets longer over time until the blade breaks. The blades have lasted anywhere from 2 hours up to 2 months. I feel the blades should last significantly longer because they are still sharp and the saw does not sound like it is working hard to cut the material.

I have attempted to re-weld the blades to repair them, but the induction blade welder I have access to does not work very well with the bi-metal style blades. With the breakage occurring with a number of different manufactures, it would appear that there is a problem with the set up of the saw. Is this blade breaking problem common with the smaller bad saws? What can I check or adjust to see if the saw is set up correctly?

Any help would be greatly appreciated.