Hardness testing

[Mark Baldwin III]

Today I took a few tools to work and put them in the hardness tester. The Veritas irons are A-2. The others are, well...whatever. I'd have to check Hock's site to verify what he uses. Anyway, the results (these should all be within 1 point on the scale):
Two Cherries 1/2" paring chisel: C61.5
Hock 1.5" plane iron: C62
Veritas skew rabbet iron: C62
Old Stanley block plane iron (30-40 years old): C59
New Stanley block plane iron: C61.5
New Stanley bench plane iron: C62
Vertias small plow plane iron: C61.5
Footprint 3/8" bench chisel: C62

I don't think this is anything groundbreaking. But I'm a geek and I wanted to know, and thought I'd share the results.

[Johnny Kleso]

They all sound on the high side.. They could all be at full hardness which is possible buy not likely..

[george wilson]

In my experience,and in my steel books,60 RC is pushing it for maximum desirable hardness for 01 steel,yet everyone seems to make them that hard. Your blades tested may also include A2. I made a knife from 01,and left it at 60 RC. I never could keep a good edge on that knife,and need to take it apart and temper it down to more like 55 RC. The microscopic edge breaks off if the blade is to hard,making it seem dull.

01 will reach 65 or so at full hardness. W1 will get the hardest at 67 RC.. HSS is usually about 63 RC,but it is highly alloyed,and in an entirely different category. HSS also will not take as sharp an edge as plainer steels due to its coarser grain structure. It was not made for cutting wood,anyway. I always found that the plane irons that I could BARELY cut with a FINE,new file would hold their edge the longest. This was in the 16 years I was using exclusively hand tools,and largely antique planes when I was musical instrument maker in costume in Wmsbg.. that would make their maximum hardness at 55 RC at the most. These were the old laminated,plain carbon steel blades.