On heat treat

[rrrgcy]

As a novice to axes (well, BSA excepted) and acquiring several contemporary new from the majors I now also have several from some of our small US forgers. I test each the same on arrival - perhaps unfair but it’s consistent - to working the front lawn roots uniformly (no pebbles, rocks, some embedded sand, though I’m really hitting mostly wood which root seems clean). The axes handle the task with ease and no harm. A recent acquisition of a model from a small forge resulted in good edge damage (see imaging). I checked the hardness and was surprised the edge was low-40’s Rc, not even 45Rc. Behind the edge 1/2” was below 40Rc. I’m guessing this missed heat treatment or was done wrong. The seller stood up to a return but I reprofiled the heaviness behind the edge and re-heat treated it (a little high) to around 60Rc and behind 1/2” around 55Rc and less away.

I’m not going to identify the maker, a couple other different products from him came with edge hardness of 60Rc, so this might have been a sole error. But it makes one lose faith that any within that model are properly hard. Last image is of my post heat treat and a 5” dia root easily worked without harm. Unsure how uncommon is a miss but I think it wise to test intended user’s edges.

 

[Square_peg]

I would keep any root work to one dedicated axe or Pulaski. And I’d want that one at about 50RC to prevent chipping.

 

[rrrgcy]

I’m familiar with the Forest Service USDA 2019 issued 5100-355F (5.2.1.2) spec for “Pulaski’s” mandated minimum 53 up to 58 Rc. Council Tools follows it and I assume others (I don’t know if CT supply the gov), but while I have a pick mattock which is fine for root I haven’t picked it up since having hoisted something similar from the early 80’s in gov service. I don’t have a Pulaski. I generally agree a mattock for roots. Respectfully, 50 Rc is too soft IMO. As with knives I’d trust slightly harder than soft - but that’s just my err’g and comfort/familiarity with working knives. Very much, my axe now near-60 Rc is quite hard. Without proximity to sacrificial tree-limbs and not wanting to wait a few months down the road when I can go to wood, my immediate on-receipt practical quality check works for me. At 60 it performed without damage with this very limited testing.

My post is that a sub-45Rc edge (& <40Rc right behind it) is just bad. Better to know early than late despite a marginal test protocol. Would you trust a maker model if you’ve bought one barely - if - hardened? With all this choice, never buy from that forge again? HT can be corrected but it’s a slight pain and why am I doing that if it could’ve just come proper? (Answer: I liked the design, it was priced easy, and I can fix a bad HT.)

 

[garry3]

I think axes made from some manufacturers are intentionally soft to avoid law suits. Can't put your eye out with steel that won't chip.

I wouldn't chop roots with any hatchet or axe I cared about, its good to have a beater around to abuse though.

 

[FortyTwoBlades]

Cutter mattocks are the geometry they are for a reason. Roots are softer than branch wood but dirt will blunt any edge, and the thin cheeks mean it stays thin-bitted as you wear your way back. Same reason eye hoes stay thin all the way back. I think Pulaskis are best using the axe bit for wood NOT in the ground, and the mattock instead. A cutter mattock is better if you need a root chopper.

 

[Twindog]

I would expect a soft edge to dent or deform. Your damage looks like chipping and cracking -- usually a sign of hardness that is too high for a task.

But I've seen bad heat treats that both chip and deform.

Below is a blade in A8(mod) that was run too soft (blades at 58 Rc would scratch it, even though the maker said it was 60 Rc). This is a very, very tough steel run soft and it cracked and chipped. Damage was caused by chopping free-hanging, green twigs. Strange.

 

[Square_peg]

I think 60 RC is too hard for most axes. That's too likely to chip when you hit an unexpectedly hard knot or when you're forced to use it in cold weather.

For root work would choose an axe mattock (cutter mattock on the East Coast). Save the pulaski for trail work where the axe is used primarily above ground and the adze/mattock end handles the roots.