Symptoms
- Blade skates across the metal surface without biting
- Cutting is extremely slow
- Blade dulls quickly on metal
- Sparks but little progress
Likely causes
- CommonWrong blade tooth count for metal thicknessThin metal needs a fine-tooth blade so several teeth are always engaged.
- CommonCutting speed set too high for metalMetal generally cuts better at a lower stroke speed than wood.
- PossibleNot enough steady pressure to keep the blade bitingToo little pressure lets the blade bounce off the surface instead of cutting.
- CommonUsing a wood blade instead of a metal-cutting bladeWood blades have coarse teeth that don't cut metal effectively and dull fast.
- PossibleNo cutting lubricant on tougher metalsSome metals cut easier and last the blade longer with cutting oil.
What to do
- Switch to a bi-metal blade with a fine tooth count appropriate for the metal thickness (more teeth for thinner metal).
- Lower the saw's speed setting if it's variable, since metal generally cuts better slower.
- Apply steady, firm pressure so the blade bites consistently instead of skating.
- Keep the shoe pressed against the metal for stability and to reduce blade bounce.
- Add cutting oil for tougher metals to reduce heat and friction.
- Replace the blade if it's already dulled from cutting wood or nails previously.
Tools and parts
- Reciprocating saw
- Bi-metal fine-tooth blade
- Cutting oil
Bi-metal reciprocating saw blade for metalSearch: “bi-metal reciprocating saw blade fine tooth”
When to call a pro
For thick or hardened metal, a metal fabrication shop or a saw with a purpose-built metal-cutting blade will be far more effective.
Safety
Use caution
Metal cutting produces sharp edges and hot metal filings; wear eye protection and gloves.