Symptoms
- Blade snaps mid-cut
- Blade flexes or bows visibly before breaking
- Cutting curves or angled cuts causes breaks
- New blades break quickly
Likely causes
- CommonBlade tension too loose in the frameA loose blade flexes excessively and fatigues quickly.
- CommonTwisting the saw sideways to steer the cutHacksaw blades are thin and brittle and can't tolerate side loading.
- CommonTooth count too coarse for thin materialAt least two to three teeth should contact the material at once; coarse teeth can catch and snap on thin stock.
- PossibleForcing the cut too fastRushing increases the chance of binding and snapping.
What to do
- Tighten the wing nut or lever on the hacksaw frame until the blade is taut and doesn't flex when pressed lightly.
- Choose a blade with enough teeth per inch that at least two or three teeth are in contact with the material's thickness.
- Keep the saw moving straight through the cut without twisting it side to side.
- Use full, steady strokes at a moderate pace rather than short, fast, forced strokes.
- Replace bent or damaged blades rather than continuing to use them.
- Support the workpiece firmly in a vise so it can't shift during the cut.
Tools and parts
- Hacksaw
- Correct tooth-count blade
- Vise or clamp
Hacksaw blades assorted TPISearch: “hacksaw blades 18 24 32 TPI”
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.