Broken scroll saw blades can be fairly common, but you still want to avoid them. They’re startling, to say the least, and it slows you down as you have to stop and replace the blade. So let’s look at why do scroll saw blades break and try to minimize the occurrence.
Wrong blade tension
As discussed in the beginning scroll saw cuts post, the tension is the tightness of the blade. If it’s too loose, it will have a hard time remaining perfectly straight and won’t cut through the material well. This can also cause tiny twist in the blade, causing a break.
If the blade is too tight, there is too much strain already on the blade and trying to cut through the material will make it snap. On my Dewalt scroll saw, when cutting 1/4 inch MDF, I keep my tension at 4.
You can search for YouTube scroll saw videos that demonstrate ideal blade tension, including the sound it will make when you gently pluck it from behind (not the teeth side!)
Scroll Saw Speed
Sometimes the speed at which the blade is moving up and down will cause it to break. When the speed is too high, you may have a harder time controlling the cuts, leading to inconsistent pressure on the wood and the blade.
Pushing the wood too hard
One of the key reminders is to let the blade do the work. Pushing the wood into the blade too much can cause overheating, in addition to the directional strain on the blade. Either of these can make a blade snap.
Blades do wear out, just like any cutting tool, and then it will be more likely to break. Often I can tell the quality of my cuts is going down if the blade has gotten dull. Maybe there is a bit of tear-out, or the top or bottom edges are getting a fuzzier.
Another clue that a scroll saw blade is dull is that you feel like you have to push the wood in more to get it to cut. Replace the blade and you’ll be a happier scroller.
Knowing when to change a scroll saw blade isn’t so much about a time limit, as just recognizing when it’s not cutting cleanly any more. This could mean changing blades after a couple of projects, or using more than one for a single project.
Pay attention to matching the right scroll saw blade to the right material or material thickness. Often the package will tell you which blades are recommended for which cuts.
When trying to cut metal, using a small blade will help you keep control, and choosing a skip tooth (more space between each saw tooth on the blade) will keep tiny metal fibers from getting stuck in the blade.
Stacked or thicker wood will usually need a larger blade to pass through the material cleanly.
How to replace a broken scroll saw blade
Even with your best efforts, a blade will sometimes break. What’s nice about having the blade tightened securely at the top and bottom is that usually, nothing will become airborne when it breaks.
Loosen the top of the blade and carefully pull it down. Then loosen the bottom of the blade and lift the wood off the table. Likely the blade will be jammed into the wood.
If the scroll saw blade is stuck, pull it through the bottom with a pair of pliers. Install a new blade and continue cutting.
I hope this post eases a bit of your fears about breaking scroll saw blades. It’s probably going to happen at some point – one of the reasons it’s so important to wear safety glasses.
But once you know why scroll saws break you can follow the above suggestions to keep blades from breaking often and interrupting your work. Do you have any more tips to share?