Vern Burke, SwiftWater Edge Tool Works
The unthinkable has now happened. You got a little to aggressive with the down force on your handsaw, dug the teeth in, and then pushed. Now your formerly straight handsaw looks like the ocean waves or a banana. In this post, I’m going to list some dos and don’ts about straightening a bent handsaw.
1. Get a real anvil. Yes, you could probably get by with makeshift using a piece of I-beam or a steel plate but trying to do this without the right gear is going to be frustrating at best. Don’t even think about trying this on the little “anvil” on the back of your bench vise!
2. Forget perfectly flat anvils. There’s a common wisdom about that anvils need to be perfectly flat to be useful. The reality is, a bent saw can never be straightened on a flat surface. Since saw steel is generally pretty springy, it has to actually be bent past straight so it will spring back to straight. Best thing for straightening a hand saw is a fairly heavy vintage anvil with a well worn face and a few depressions (aka negatives).
3. Take the handle off the saw. Don’t even think about trying this with the handle on.
4. Don’t ever strike the saw blade directly. Place another tool against the saw blade and strike that tool with the hammer. Strike the blade directly with the hammer and you’ll leave tool marks on the blade, among other things.
5. Don’t over hammer the blade. A bent saw blade will never go back to factory perfect. The object here is to get the blade straight enough to cut a straight line with minimal correction.
Over hammer a blade and you’re likely to thin out the metal, especially if you’re violating #4 and hammering directly on the blade. This is guaranteed to ruin the blade.
These are just the high points to watch for on straightening bent handsaw blades. Most bent handsaws can be put back in shape with care and practice. Or you can bring them by and let us bring them back to life for you :).