Kink in 4x6 bandsaw blade

When I run my 4x6 bandsaw there is a distinct moment on each rotation of the blade where there's a "whump" sound and the saw bounces slightly. On the face of a thin cut (where the saw is moving through the stock fast enough) you can see these points as gashes in the face of the metal.

The blade doesn't look any different as it passes over the stock at that point (there's no weld, and it's not missing teeth). The only difference I see is that if I watch the blade before it enters the guides I see a slight inward twist that seems to correspond to the whump. The twist seems to be removed by the guides. I have the tension as tight as I can get it by hand.

Was this caused by leaving the bandsaw tensioned between uses? Can I fix that kink? Should I just toss the blade (hate to, since it's relatively unused).

Reply to
Ben Jackson
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"Ben Jackson" wrote (clip) Was this caused by leaving the bandsaw tensioned between uses? ^^^^^^^^^^^^ Probably not. ^^^^^^^^^^^^ Can I fix that kink?(clip) ^^^^^^^^^^^^ This trick works on carpenter's saws--it's possible you could make it work here. Hold the blade on a flat metal surface (like an anvil), with the curve pointing up. Holding the blade as flat as you can, gently tap the metal with a light hammer. Each hammer blow will raise the stress locally above the yield point, so the metal gets flatter. Of course, be careful not to hit the teeth, or you will screw up the set.

Reply to
Leo Lichtman


Sure there's a weld. It may have been well-blended, and perhaps even re-blued after grinding -- but there's a weld. And because of that, there's a slight change of geometry there. Maybe it's thicker or thinner than the rest. Maybe the teeth skip a stagger at that point.

If you're sure you can spot the 'twist', you can probably fix it with judicious use of a hammer on an anvil (with the blade off the saw). But you should have numerous blades "in stock". It's a bitch to break your last one during a job.


Reply to
Lloyd E. Sponenburgh

I've had the same problem. I straightened the kink on an anvil and then continued to use it until the blade finally broke. It will probably break at an inopportune time, so have a spare handy.

Reply to
Gary Brady

What I meant was that the spot doesn't correspond to the weld in the blade, which is visible.

Thanks all for the pointers.

Reply to
Ben Jackson

could it be when the weld passes around one of the wheels is when the 'bump' happens ?

Reply to
j.b. miller


I have a Horror Fright 4x6 bandsaw that does the same thing. On mine, both pulleys have significant runout. Switching to a Starrett blade helped, but I suspect that correcting the runout is the real solution.

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