GemRed 82412 Digital Angle Gauge Review
A magnetic box that tells you the blade is at 44.7 degrees when the saw's own scale says 45. Cheap, and it improves every cut.
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Every saw has an angle scale moulded or cast into it, and every one of those scales is approximate. The pointer is thick, the increments are coarse, and the whole assembly shifts the first time the saw is knocked or the trunnions are adjusted. A mitre that should be 45 degrees and is actually 44.6 produces a picture frame with four visible gaps, and the scale will keep insisting it is right.
A magnetic angle gauge removes the argument. It is an inclinometer in a small box with magnets in the base and a backlit display.
The technique that makes it accurate
The gauge on its own measures tilt relative to gravity, which is not what you want — your saw is not level and does not need to be.
Instead: sit the gauge on the saw table and press zero. The gauge now treats the table as its reference. Move it onto the blade and the display shows the angle between blade and table, which is the only angle that affects the cut. The floor, the bench and the machine’s levelness drop out of the calculation entirely.
The same method works for a jointer fence against its bed, a drill press table against its column, and a bandsaw table against the blade.
Where it will lie to you
It reads the surface it is stuck to. Two failure modes follow.
Resin build-up on a blade is not flat, and a gauge sitting on it is measuring the resin. Clean the plate.
Teeth are set outwards from the plate. A magnet spanning two tooth tips measures the tooth set, not the blade. Sit it on the body of the blade between teeth.
Also: strong magnets can nudge a bevel that is set but not yet locked. Set, lock, then measure.
What it cannot do
This measures tilt. It cannot tell you the angle of a corner in a room or copy an angle off an existing piece. That is a digital protractor’s job, and it is a different tool.
What works
- Zeroing on the saw table and then reading the blade gives you the angle between them, so the machine does not need to be level and usually is not
- The magnetic base holds it on a blade or a fence one-handed, leaving the other hand for the tilt lock
- Backlit display is readable inside a saw cabinet, which is exactly where you are trying to read it
What doesn't
- It reads whatever it sits on — resin on the blade or a tooth under the magnet gives a confident, wrong number
- Plastic body with a battery hatch that is easy to lose the cover from; this is a tool to keep in a drawer, not loose on the bench
- It measures tilt only, so it cannot read the angle of a corner or transfer an angle off existing work
Worth comparing against
- Check price
GemRed
GemRed 82305 Digital Angle Finder Protractor, 200 mm