A fret saw has a very thin blade mounted in a metal frame. Like all frame saws, the blade must be held taut in order to cut efficiently.
The blade is held in place by the arms of the frame, which clamp either end of the blade, preventing it from falling out.
These clamps are loosened and tightened by turning the wingnuts located just below them.
Removing the blade
Step 1 – Turn wingnut anti-clockwise
Loosen the wingnut furthest from the handle by turning it in an anti-clockwise direction.
Loosening the wingnut causes a small clamp on the arm to open, releasing the blade.
It will also cause the arms to move out, back to their normal position, as the blade is no longer held under tension.
Step 2 – Loosen second wingnut
Loosen the wing nut closest to the handle by turning it anti-clockwise.
This will release the other end of the blade, which can now be removed completely, and set aside.
Installing the blade
Ensure you place the blade in the frame with the teeth on the outside, and the points of the teeth facing back towards the handle. This is so the saw cuts on the pull stroke
Step 1 – Compress frame
To install a blade, you will need to push the arms of the frame inwards, towards each other, so that they are close enough to accept the fret saw blade.
The best way to do this if you are on your own is to wedge the arm of the fret saw up against a corner, and push the handle side inwards, until the two arms are close enough for you to slide the blade in.
Step 2 – Insert blade
Slide one end of the blade into the clamp nearest the handle, then slide the other end of the blade into the clamp furthest from the handle.
Step 3 – Tighten wingnuts
When the blade is sitting straight, turn the wing nuts in a clockwise direction to tighten the blade.
Once the wing nuts are tightened, the arms of the frame are naturally trying to pull outwards, and, as a result, they stretch the blade taut.