Any idea what steel these are made of? Jaws of life blades!

SkagSig40

SkagSig40

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Feb 1, 2001
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I collect all kinds of odd and rare steel items to go with my knife collection. Recently I came across this set of "jaws of life" blades. I did a little research but could not find what these are made of or how hard they are. Anyone have any ideas? I bet they are proprietary and the specs are secrete. Also any one have any leads on where I can find another used or worn out pair? I'll try all the fires houses in my area soon. Thanks!


 
Chris I was a OKC firefighter for 23 yrs and used the jaws of life many times.
I found your post interesting so I looked around the net just a little.
We had Hurst tools in OKC so I googled them and found this.

Hurst uses a forged shock-resistant tool steel that has been uniquely heat treated using a four-step tempering process in all the Jaws of Life® cutter blades which makes the blades chip and dent resistant while maintaining ductility.

Nothing specific but maybe someone will know.
 
I've seen information on this as I'm interested as a metallurgist in new alloys for car safety. Many new types of tough ,energy absorbing steel have been developed and that have required improvements in better
steels for the jaws ! IIRC the strongest steel used in cars today is a hardened boron containing steel and that required a better jaws steel. I'll tryto find it as it is out there somewhere !

The worst place on a car is the door hinges and a brace made of the boron steel. You might contact Hurst. I've seen a paper about this and it is fairly new. I'll keep looking !

http://www.resqmed.com/BoronSteel1.pdf
Lots of info out there !
Have fun !!
 
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Likely it has a really REALLY high heat treatment and you'll likely only find it labeled as tool steel
 
It seems reasonable to assert that the metal doesn't need to have terribly good edge retention properties given the sheer mechanical force behind them. They're not fine scissors that keep a keen edge as much as a power tool that brute forces its way through sheet metal of a much lower grade. I'd guess any decent tool steel would do the trick.
 
I could swear I saw a how it's made episode where they said it was chromolly like 4140 but I could be totally wrong.
 
Never mind ignore my post I just you tubed the episode and it just says tool steel.
 
Caterpillar tractor was the only company I remember that used it on a regular basis back in the 1960s. Most are typical alloy steels with Small .003-.005 % amounts of boron added. That small amount will raise the hardenability a significant amount. That was the start of " micro-alloying "
 
I don't see the type of steel used, but I do see key words:

laminated steel
drop forged
shock resistant
special heat treat
replaceable
stainless steel investment cast


I get the sense that the new high-strength steels used in cars has to be overcome by increased spreading/cutting power, more than steel type used in the jaw tips. Also, fire departments are having to change their techniques for opening cars.

Makes you wonder what kind of knife could be forged out of those jaw blades.
 
Twindog said:
I don't see the type of steel used, but I do see key words:

laminated steel
drop forged
shock resistant
special heat treat
replaceable
stainless steel investment cast


I get the sense that the new high-strength steels used in cars has to be overcome by increased spreading/cutting power, more than steel type used in the jaw tips. Also, fire departments are having to change their techniques for opening cars.

Makes you wonder what kind of knife could be forged out of those jaw blades.
Click to expand...

If there was enough steel there, make a hell of a machete especially if they got the same heat treat as before. Be hard as hell to sharpen but probably never roll an edge or anything. I'm not sure bout pocket knife because those aren't needed to be sharp and may not keep a hair shaving edge but just a working edge instead
 
Probably INFI
 
According the pdf (linked by Mete) Boron steel Yield Strength(YS) is around 200kpsi (~1378 MPa). Generous projection for Boron Steel's Ultimate Tensile Strength = YS * 1.2 = 1654MPa.

So basically, a good YOL steel should has YS at least 2000 MPa. btw - hardened 52100 YS is around 2000 MPa.
YS = max strength in elasticity zone before enter plasticity/fracture zone.
UTS = fracture/break point
https://en.wikipedia.org/wiki/Ultimate_tensile_strength
 
I'm betting the exact steel formulas for Jaws are proprietary. Several companies make them don't they, isn't it competitive?

This reminds me of the guy I found on the web who makes skeleton knives out of new DeWalt reciprocal saw Rescue blades, leaving the original teeth on the spine. Supposedly some of the toughest stuff out there. I keep meaning to buy a couple of his blades, they're pretty cool, cheap and have to be tough.
 
EChoil said:
I'm betting the exact steel formulas for Jaws are proprietary. Several companies make them don't they, isn't it competitive?

This reminds me of the guy I found on the web who makes skeleton knives out of new DeWalt reciprocal saw Rescue blades, leaving the original teeth on the spine. Supposedly some of the toughest stuff out there. I keep meaning to buy a couple of his blades, they're pretty cool, cheap and have to be tough.
Click to expand...

Got a link to those blades? Thanks!
 
SkagSig40 said:
Got a link to those blades? Thanks!
Click to expand...

Ya know, I do. I'll have to find it though. I want to go there again anyway, take another look at them. As I recall they're pretty cool little dudes.

I'll hit you with it here tomorrow if I can find it.
 
That Boron carbide steel is stout stuff. I recently had to cut off a new Master Lock at work. We used a portable band saw. This band saw eats through anything with no problem. I actually cut a good 25/64" drill bit (which should be a decent, hardened tool steel) today with it, and it took about 5 seconds. That damn Master Lock, with its "Boron Carbide" steel shackle took about 5 MINUTES! It was pretty insane. Now, maybe that was actual carbide, not just a boron alloyed steel, but it was impressively difficult to cut.

I wouldn't expect those jaws to be the best knife blade steel, however. Their use is so vastly different than a knife. They need to be incredibly tough, fracture-resistant, and ductile. Unlike a knife, I doubt wear resistance or edge retention is high on the priority list. They would surely still work with a poor edge. They are hydraulically driven after all.
 
I think your shackle had a BC coating to make it saw resistent .Boron alloys have small amounts of boron which increases hardenability .
 
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