Makita recipro saw blade B-52118, special purpose, for glass wool and stone wool. Sold as a pack of two. Universal shank, fitting Makita reciprocating saws and other sabre saws with a standard fitting.
Why insulation needs a special blade
Mineral wool does not cut, it compresses. An ordinary toothed blade pushes the fibres aside, drags, and leaves a torn and inaccurate edge — which matters, because insulation only performs if it fits the stud bay tightly with no gaps. This blade uses a long, coarse wavy edge that slices through the batt in a single pass instead of trying to saw it.
Working with mineral wool
- Cut batts slightly oversize — around 10mm — so they friction-fit without being crushed.
- Compress the batt lightly against a straight edge and cut in one steady stroke.
- Wear a mask, gloves and long sleeves. Mineral wool fibres irritate skin and airways.
- Keep this blade away from timber and metal — one encounter with a nail will finish it.
