12-27-2012, 05:54 PM
Good points posted by all, particularly that which DaveH and TomG have highlighted...cutting speed. The most common mistake in using them is overspeed. Perhaps it's because they so resemble wood cutting circular saw blades, one might get lulled into a false sense of "speed looks OK". Check it, matching your saw's material (HSS, HSS-Co or carbide) to the material being cut.
When using simple, plain single-cut slitting saws, that is ones with no side cutting relief, avoid cutting any deeper than the depth of the hook on the teeth. If you bury one of those in most materials, the chips will be the same width as the saw and in a deep cut those teeth will often become one of the chips being ejected from the cut. ;) Curiously, those very shallow cuts (such as slotting screw heads) is one of the few times it's perfectly safe to climb mill.
Deeper cuts need side relief, such as that shown in the photo TomG posted further up this thread. If not side cutting clearance, at least use very coarse pitch saws. The overall feed per tooth at even slow feed rates can add up to a high-torque cut when you engage a great many teeth with a long contact patch. That's a formula to overpower a spindle motor and stop it in midcut. This can happen by way of shearing the saw right through the soft drive key (if there is one) or just stopping the motor because it's low speed puts it at the bottom of it's avaialble torque output.
When using simple, plain single-cut slitting saws, that is ones with no side cutting relief, avoid cutting any deeper than the depth of the hook on the teeth. If you bury one of those in most materials, the chips will be the same width as the saw and in a deep cut those teeth will often become one of the chips being ejected from the cut. ;) Curiously, those very shallow cuts (such as slotting screw heads) is one of the few times it's perfectly safe to climb mill.
Deeper cuts need side relief, such as that shown in the photo TomG posted further up this thread. If not side cutting clearance, at least use very coarse pitch saws. The overall feed per tooth at even slow feed rates can add up to a high-torque cut when you engage a great many teeth with a long contact patch. That's a formula to overpower a spindle motor and stop it in midcut. This can happen by way of shearing the saw right through the soft drive key (if there is one) or just stopping the motor because it's low speed puts it at the bottom of it's avaialble torque output.