Properly maintained cold saw blades should last a long time, even with extensive use. One tip to prolong the life of your saw blade is to be meticulous when changing the blade on your saw. Listed below are simple, yet critical practices to follow every time a blade is changed.
The saw blade is driven by the pins in the flange. When changing blades, the Backlash MUST be removed or "Taken-Up", and it's very simple to do. When the blade is put on the machine (but before the final tighten) lift up on the front of the blade and hold it in place, then fully tighten the bolt. By holding the blade against the pins of the flange, it will keep the pin-holes in alignment and restrict blade movement.
A Dirty Flange happens when metal chips were allowed in-between the Flange and/or the saw spindle when the blade was mounted. By failing to clean between these components, on either side of the saw blade, is like bolting a wheel onto a hub and putting a rock in between them before tightening the wheel to the hub. This will cause the saw blade to "wobble" and appear to have excessive run-out. When operating with a Dirty Flange, the saw blade will not cut properly and will lead to other saw blade problems, especially Pick-Up.
Pick-up happens when the material being cut has bonded itself to both sides of a tooth on the blade, making it wide or thicker than the initial saw blade. Every time that thicker tooth passes through the material being cut, it will grab or catch the material and cause the head of the saw to jump -- generally with a loud "clunk, clunk, clunk" sound. The pick-up will get worse with each pass through the material. Many users will often think the saw blade is "out-of-round" because of the way it feels during the cut, but the issue is usually blade tooth pick-up.
At some point, the pick-up will cause the blade to jam in the material and either rip a chunk out of the blade or break the blade into several pieces. Pick-up can also cause the material to move during the cut; either the material will roll or move, or the blade will be forced off to one side which causing your cut to be off square.
Pick-up can be felt by dragging a fingernail over the side of the teeth on your blade. If you feel pick-up on the blade STOP using it or you risk a broken blade. When caught early it is best removed by smoothing it off with a hand-held hone-stone...NOT with a power tool! If too much is taken off, you will make the blade thinner, which will result in other issues. Note: most often you will continue to get pick-up in the same spot as the finish on the blade has been compromised. The best way to get rid of pick-up is to have the blade professionally resharpened.
Material Slipping in Vise
The material must be properly seated and clamped tight in the vise. If the material moves during the cut it can bend or break the saw blade. Pick-up can be a major contributor by grabbing onto the material being cut. Evidence of this is an unusual rub mark typically on one side of the blade.
Read more on how to improve the life of your cold saw blade in Scotchman's Cold Saw Blade Basics OR in 5 Tips to Extend the Life of Your Saw Blade.