Saturday, October 8, 2011

V2.23 - Choose the correct Band Saw blade.

Alright, we’ve got the saw cutting straight and the blade is tracking properly, but is it really cutting as good as it could? Let’s talk about that.

A band saw blade is a delicate piece of steel that is subjected to a tremendous strain. If you treat the blade right, you can get a pretty long life out of it. Basically, you’ll need to be sure to select a blade of the proper thickness, width, and temper for the material that you’re going to cut.
Always use the widest blade possible. Narrow blades should be used only when sawing small, delicate items or when making abrupt curves. Using narrow blades for resawing or heavy-duty work will just cause them to fail all the sooner.
Some band saws are made to cut ferrous metals (iron & steel) and the blades for that should be selected based on the particular job they are going to do. A metal-cutting blade should always have two teeth on the cross-section of the metal. For instance, if the cross-section of the metal is ¼” thick, you would want two blade teeth in contact with that, and since there are four ¼ sections in one inch, the blade should have 8 teeth per inch. If fewer teeth are used, the teeth will straddle the work and may be torn off and the blade ruined. If too many teeth are used (say, a 16 teeth per inch blade) the metal chips cannot clear out properly and the blade may overheat and ruin its temper… again making the blade worthless.
In general, the thicker the stock to be cut, the more teeth the blade needs to have and, in the case of a wood-cutting blade, they need to be larger teeth. Also, the thicker the stock, the slower the cutting speed needs to be.
So, what if you have used care in selecting the proper blade and you keep breaking your blades? Any one of a number of conditions may cause a band saw blade to break. Sometimes it’s just gonna happen no matter what you do, but most of the time, it can be traced to some basic things: 1- faulty alignments and adjustments of the blade guides, 2- forcing or twisting a wider blade around a short curve, 3-shoving the stock through too fast, 4 using a dull blade and trying to force it to cut anyway, 5- excessive tightening of the blade, 6- top guide set too high above the work being cut and lastly, but certainly not least 7– using a small 3-wheel band saw. Those little beasts just EAT blades… they can’t help it, they just do.

Send your questions or comments to: and we’ll see what we can do to help you.

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