Minimum HRC?

[Stephen Conkie]

Hi guys
What would you say is the minimum HRC acceptable for bushcraft and is it different for non-specialist knives? I assume there's a large difference in the demands made in the two different environments? Can you use a softer edge if it has a better grind? I tried putting a point on a piece of wood with my clipper (no problem) and my Whitby (getting the job done, but a lot more effort). Afterwards there was no appreciable difference in the keen-ness of the edge on the Whitby, so I was thinking it was the grind that let it down, but maybe I'm misinformed?

 

[NatG]

i imagine it was the grind that was the problem, the moras are pretty much set up for wood carving, whereas i imagine that your whitby has a pretty obtuse edge abgle and a flat or hollow grind, which is not neccessarily optimised for wood carving.

in as much as that a harder knife can be brought to a sharper edge, the harder the better for woodwork

 

[Stephen Conkie]

The Whitby is definitely for High St/ Fishing-shop market, with no real grind at all, apart from the last couple of mils. I've seen Puukkos with an HRC of 54 - Ragnar @ ragweedforge doesn't consider <56 worth buying, but say that one xly famous bushman (whose name I can't remember) had commented that he'd love to've been able to find a softer edged knife. I suppose this is like beginning guitarists talking about pickup power or something....something you rapidly "get over"

 

[wanderingblade]

I believe the 56 - 58 range is considered optimal as you want a blade to be hard enough to retain a good edge but not too hard or it could chip and would be harder to sharpen.

In the end it comes down to personal taste and trade off between edge retention and ease of maintenance / sharpening.

Softer blades are perfectly useable, they will just lose their edge faster.

 

[Shinken]

Well it all depends on the steel, different steel performs differently at the same hardness.

For 1% carbon steel blade about 58-59 hrc is about right.

 

[Stephen Conkie]

I've just seen 12c27 given as 58, but have also seen it quoted as 57. I take it the same alloy can have a dfrnt rating depending on how its been treated?

 

[Martyn]

Softer blades are perfectly useable, they will just lose their edge faster.

Agreed, there is no "optimal" hardness as such, it's just taste. Soft edges can be bought to a ferociously sharp edge, but they will dull quicker. Hard edges are harder to sharpen, but last longer. Soft edges tent to roll, hard edges tend to chip. It's just taste. Somewhere between 54 and 58 would be fine for general woodwork. You can tolerate a softer edge better if t he knife is used mainly on green wood. High RC of 56 and above are good for general duty knives for use on a wide variety of material (eg folding knives). People often make the mistake of thinking harder is better, it's often not the case. For green wood, I like a softer steel that I can keep to a very fine, razor edge with regular touch-ups and light stropping.

 

[Shinken]

Yup just try different hardness blades and see what you like.

I have a knife in cpm 3v and its 60hrc and will chip less than knives ive owned in 01 that was 58hrc.

But it's still a little harder to sharpen.

 

[Hoodoo]

I remember a time when 56 was just fine and used by folks who spent a lifetime in the wilderness and didn't know they were "underknived."

 

[jojo]

What about the folk who used flint, then copper, then bronze? What was the hardness with those materials? They seem to have done just fine...

Bronze edge orientation day.

 

[Shinken]

Yup not doubt they did fine, but there is also a reason that when steel came along they ditched the flint and bronze

 

[Stephen Conkie]

Did anyone watch BBC2 the other night and see the thing about the Siberian horsemen? They're walking around in crappy jumpers and Russian Army-Surplus thin cotton jackets with no gloves on...totally unphased in minus 30!