Est. 1998 — 27 years of woodworking knowledge
Question about steel
Denis Chénard, Orléans, Ont.
>Can HSS jointer/planer blades be made as sharp as steel used in handplanes (like A2)?
Will the edge last as long? I suspect not, but why? Is is a toughness requirement for power tools blades that handplanes need not bother with?
Curious, wish I understood more the whole steel thing...
DC
Sharpening HSS Blades *LINK*
Steve Elliott
>I've been sharpening and testing blades made from a number of types of steel, including an M2 high speed steel (HSS) plane blade by Academy Saw Works. When honed on waterstones the HSS blade would not take as sharp an edge as either A2 or high carbon steel. Repeated careful honing using Shapton, Norton, and Takenoko stones just wouldn't give me the really sharp edge I could get on the A2 and carbon steel blades.
When I used fine diamond paste on a cast iron lapping plate for the final honing, the HSS got just as sharp as any blade I've tested. I believe the carbide particles in the HSS are harder than the aluminum oxide abrasive in the waterstones, causing the particles to just fall out as the surrounding steel matrix is worn away. Since diamond is harder than carbide, honing on diamond actually brings the carbide particles to a sharp edge instead of just causing them to dislodge.
The HSS blade held its edge much better than the A2 and especially the high carbon steel. It didn't chip any more than the high carbon, and chipped less than the A2 at a bevel angle of 32 degrees. The link below gives details of my latest tests. The light blue lines on the charts show the results for the HSS blade.
The one drawback of the HSS is how long it takes to grind and hone. I'd suggest trying HSS only if you're good at sharpening or want something challenging to practice on.
Plane Blade Tests
more about carbides
bill tindall
>Steels are formulated with carbon and the purpose of this carbon is to make carbides. The different elements that are used to alloy steel result in carbides of different hardness. Iron carbide is one of the softest while vanadium and tungsten are the hardest. As a result steels high in vanadium are very abrasion resistant, for example CPM 3V.
I have a photomicrograph of a diamond sharpened CPM 3V edge and the scratches run right through the carbide particles, without hesitation.
Aluminium oxide is the abrasive encountered in grinding wheels, bench stones, and most likely water stones. It is not very effective at grinding carbide tools, so it is a good bet that it has problems with steel alloys that have abrasion resistant carbides.