How well does INFI hold up up above 60 rc?

230grains

230grains

Joined
Jul 10, 2009
Messages
3,094
Yes, before anyone says it, this should absolutely void any warranty of blade failure, as it's completely altering the blades original spec, and you would absolutely be losing impact toughness. One would not expect Busse to replace/fix any damage caused by this.

I was just curious if any of you have ever rehardened or had your INFI rehardened? I think INFI is tempered absolutely perfectly for hard use application. When encountering material that's harder, it tends to roll and not chip etc.. But the idea of the BAD being hardened differently than standard Busses is intriguing to me. I have considered buying a BAD to test it out, but the thin tip scares me. I was just pondering the idea of an active duty/meaner/gw style blade, hardened around 61, and how useful it could be. Sure you would lose quite a bit of impact and lateral stress resistance, the edge would probably chip out rather than dent when met with harder material, but for a knife used solely as a slicer, not a hard use knife, it wouldn't be too much of an issue.

Has anyone had this done? I have access to millions of dollars worth of furnaces, RC testing equipment and friends who are experts in metalurgy/heat treating. One of the perks of working for a very large machine shop. I'm almost considering picking up a skeleton key.... :eek: :p Just kidding of course......

One steel that i'm very interested in is CPM m4, and it's ability to be hardened very high, and ground very thin yet still hold an amazing edge and remain strong. For you BAD users, how do they hold up? Have you had any issues? Were any other Busse blades hardened higher than usual besides the BAD? What about a Differential heat treated blade? 61+ edge, 58 blade. How hard can you actually get INFI? I must be tired, or crazy. :foot:
 
If I remembering correctly (and I'm probably not), the bad's are 60rc, and the original wasp battle mistress (and a few others in the first batches) were in the 62rc range. they were also thinner at the edge then most of what is produced now. From everything I've heard the wasps have held up extremely well.

jerry has said previously that infi doesn't do well with differential heat treating because it spreads heat out too quickly through the steel matrix. I have no idea about the upper reaches of it's hardenability, I don't recall jerry ever posting about it. Most of what I've seen about 65rc-69rc has been with 1095 and zdp.
 
Thanks LVC, that's pretty much what I'm looking for. I definitely trust Jerrys opinion on differential heat treats and INFI, was just curious more than anything.

I've never even heard of the WASP BM, but i'm intrigued. I don't know if i'd want a 62 RC thin ground chopper though, i'm thinking a lot smaller. Were there any other smaller knives hardened higher?
 
INFI should hold up extremely well at 62 rc (and has been done before). There's not enough carbon to reach 65 rc post-temper though. Anneal, 2050F austenization, cryo-quench, and 950F triple-temper should do the trick.
 
cotdt said:
There's not enough carbon to reach 65 rc post-temper though.
Click to expand...

huh?

I don't think much (if any) of the carbon content is burned out or reduced during the initial production heat treating, so it should all still be there and available for hardening. I don't know much of anything about metalurgy so I couldn't comment on the ability of infi's high nitrogen, low carbon, high alloy composition to reach high hardness's in the first place, but theres definitely enough carbon to reach 65rc first production run, so there should be enough still there to do it again second hand.

lol, scratch that. see post directly below. i was right in thinking the wasp was 62 instead of 65.
 
Last edited:
There was never a 65 RC mistress. INFI just won't go that high. 60-62 is about max. :thumbup:

Hope that helps,

Jerry :D


.
 
Jerry, so was the WASP mistress in the thread I posted actually 62 rc?

How did you find it held up as far as choppers are concerned?
 
230 -- what are you thinking of using the BAD for? The tip certainly wouldn't hold up to prying doors (or stuff around the machine shop ;) ), but it does fine otherwise. I've done bow drill divots in wood, done fine carving in wood, popped out notches in wood, etc. General kitchen duty, cut heavy zip-ties, etc.

The BAD is one blade I wish I had the money to buy 5 of.
 
I have all the answers for you 230:)

For all of your heavy work:
MS880.gif


For your cold weather splitting, just stick it in your pack:
24AD597D766_500.jpg


For when things get a little complicated around the shop:
gooseneck-wrecker-bar-24-1001470-15.jpg


Your daily driver:
3-army-tank.jpg







:D
 
230grains said:
Yes, before anyone says it, this should absolutely void any warranty of blade failure, as it's completely altering the blades original spec, and you would absolutely be losing impact toughness. One would not expect Busse to replace/fix any damage caused by this.

I was just curious if any of you have ever rehardened or had your INFI rehardened? I think INFI is tempered absolutely perfectly for hard use application. When encountering material that's harder, it tends to roll and not chip etc.. But the idea of the BAD being hardened differently than standard Busses is intriguing to me. I have considered buying a BAD to test it out, but the thin tip scares me. I was just pondering the idea of an active duty/meaner/gw style blade, hardened around 61, and how useful it could be. Sure you would lose quite a bit of impact and lateral stress resistance, the edge would probably chip out rather than dent when met with harder material, but for a knife used solely as a slicer, not a hard use knife, it wouldn't be too much of an issue.

Has anyone had this done? I have access to millions of dollars worth of furnaces, RC testing equipment and friends who are experts in metalurgy/heat treating. One of the perks of working for a very large machine shop. I'm almost considering picking up a skeleton key.... :eek: :p Just kidding of course......

One steel that i'm very interested in is CPM m4, and it's ability to be hardened very high, and ground very thin yet still hold an amazing edge and remain strong. For you BAD users, how do they hold up? Have you had any issues? Were any other Busse blades hardened higher than usual besides the BAD? What about a Differential heat treated blade? 61+ edge, 58 blade. How hard can you actually get INFI? I must be tired, or crazy. :foot:
Click to expand...

I've had several BADs ... still have 2 or 3. I've only used the BAD as a slicer -- and it is superb at that. The edge holds and holds for me ... not at the "super sharp" level, but at the "pretty doggone sharp" level. [We really need some new terminology for this.]

I actually did give some thought to rehardening a different Busse, but it would be more difficult for me to arrange these days. I no longer own and operate laboratories.:(

I think it would be worth trying, so long as the owner remembers that the original warranty is voided. I would consider it only for the smaller knives that are best used as slicers (a Meaner family blade, for example).
 
I absolutely would NOT try it. There's no way you'd be able to match Jerry's heat treatment for strength and durability.
 
Only the experts should attempt to reharden INFI... experts like Jerry or OP. :D
 
richstag said:
I have all the answers for you 230:)

For all of your heavy work:
MS880.gif


For your cold weather splitting, just stick it in your pack:
24AD597D766_500.jpg


For when things get a little complicated around the shop:
gooseneck-wrecker-bar-24-1001470-15.jpg


Your daily driver:
3-army-tank.jpg







:D
Click to expand...

LMAO, i'm gonna need a bigger pack.

Does anyone make an IWB holster for an m198 Howitzer?
 
Amoeboid said:
I absolutely would NOT try it. There's no way you'd be able to match Jerry's heat treatment for strength and durability.
Click to expand...

I don't know, we've been keeping tanks moving, planes in the air, helicopters flying high and space shuttle parts working great for years. If you've flown in a plane recently, theres about a 75% chance something me or a coworker made is in it. I'm not a metallurgist, but I know some very good ones, surely good enough to HT a knife to the correct RC hardness.
 
Jerry Busse said:
There was never a 65 RC mistress. INFI just won't go that high. 60-62 is about max. :thumbup:

Hope that helps,

Jerry :D


.
Click to expand...

Boss, well that is good to know and the misconception from the wasp knife is over, lol. So it was no different than the other original SHBM's, fact is always better than myth:D
 
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