The Atoma Diamond Sharpening Plate #140 is the coarsest plate in the range - and the one you reach for when refinement isn't the priority, speed is.
At 120 microns, this is an aggressive sharpening plate designed for the heavy work that finer grits simply can't handle efficiently:
- Re-establishing primary bevels on chisels and plane irons
- Repairing damaged or chipped edges where significant material needs removing
- Flattening the backs of new chisels that arrive from the factory less than true
The generous diamond coating costs a little more than finer grades - larger diamonds are more expensive to apply - but the removal rate justifies it. Even after the plate beds in and loses its initial bite, which is entirely normal, it continues to remove material at a pace that finer plates can't match.
One honest note: if you've picked up a secondhand chisel with a badly domed back and you're hoping this plate will sort it, please get in touch before ordering. With the right technique it's achievable - but without it, it's a fast way to spend a lot of time going nowhere.
The critical quality indicator to look for in a diamond sharpening stone is monocrystalline diamonds (each piece of grit is a single solid diamond) they are more expensive to produce but much more durable than polycrystalline diamonds.
The Atoma diamond sharpening plates we have inspected have all been remarkably flat.
Plate size: 210mm x 75mm (8¼" x 2⅞")
Do:
Use plenty of fluid and light pressure.
Fading the pressure out gradually as you finish will leave a finer scratch pattern and reduce the amount of strokes you need to take on the next plate.
Use light pressure, the diamonds are cutting tools and if you let them do their job they will serve you well for many years.
Expect all diamond surfaces to have a vicious bite initially and then gradually bed in over the first few uses, this is completely normal. As long as you keep them clean and cool and avoid using too much pressure they will cut like the wind for years.
Use liberal quantities of some kind of fluid on them, water with a few drops of dish soap, window cleaner, water treated with HoneRite Gold all work well.
Light contamination can be cleaned from the surface with an ordinary pencil rubber (eraser), if they get really grubby, moistening the surface with a bit of white spirit will help to lift the crud.
Don't:
Avoid using them with soft metals like brass, wrought iron or aluminium as these will gum up the surface and are impossible to remove.
Avoid using them for the bevels of laminated blades as the backing material is often soft and will gum up the surface.
Avoid using too much pressure, especially on the edges, the diamonds themselves are virtually indestructible, the electroplating that holds them to the surface will last much longer if you don't lean on it and scrub.
Avoid using oily lubricants on them, the greasy residues attract dust which will gum up the surface.