Type of steel used for wrenches?

ColsonCustoms

ColsonCustoms

Joined
Oct 19, 2015
Messages
76
I have been making wrench knives for a while now with mostly good results. Not as happy with the hardness as I could be though. Even after quenching, I can often get a file to bite in a little bit. It definitely hardens, just not as much as I would like.
What is this mystery "chrome vanadium steel" that is used? 4140, 4130, 6150, 5160, A2?
Are there certain brands of wrenches that have better steel for knife making? Mainly just looking for +.5% carbon.
Lastly, if it turns out that they are all made out of 4140, are there any ways to squeeze more hardness out of that steel?
 
It's equivalent to 8650 IIRC of course if it's "real" Chrome Vanadium seeing as it's not an actual specification of steel.
 
8650 doesn't have vanadium. It is likely/possible that the wrench steel doesn't fit into a SAE or AISI spec. Whatever it is, it probably has 0.3 to 0.5% carbon as you mentioned, with a max hardness in the 50s RC.
 
That is what I am afraid of. Seen various graphs for .3-.4% carbon steel(s) tempering out to between 48-53 and one as high as 55rc.
55 rc would be acceptable considering this started out as something other than a knife.
Not sure if I can gain a few points by doing a water quench and tempering to 300-350 instead of 425.
This may sound crazy, but would a cryo cycle between tempers be an option? I sell quite a few of these knives and any way I could gain some hardness would be awesome.
 
Just curious....why are you making knives out of wrenches, especially when you don't know the steel type and are already concerned about the hardness? Is it just for practice or do you already have a huge stock of wrenches?

ColsonCustoms said:
Not sure if I can gain a few points by doing a water quench and tempering to 300-350 instead of 425.
.... any way I could gain some hardness would be awesome.
Click to expand...

You could gain a few hardness points if you used 1084 or W2. :)
 
Because there is a market for them. I make more expensive blades out of various better quality steels. Just trying to make something that sells well already, into a better product. But I appreciate your thought provoking feedback.
 
I think my question was a valid one.....and I really didn't know the answer. If they sell well for you, then have at it.

I was just confused as you were not totally happy with the performance, looking for something with more carbon and looking for ways to get more hardness out of your mystery steel. And evidently, possibly looking to buy a certain brand of wrenches with more carbon. All of this I ascertained from your own posts.

It begs the question...why not use good known steel to start with? It's certainly cheaper than buying wrenches. But again, if they sell well for you....

I am curious also, do your buyers of these wrench knives know that the performance is not on par with good cutlery steels? I mean, buying a novelty with that understanding is one thing, but thinking that's the performance to be expected from a handmade knife is another.

I would think that if one was wanting to make a knife, they'd want to make the absolute best knife they could.
 
I'm guessing he is using wrenches because he is leaving the closed wrench end on the end of the handle and forging the rest into a blade. That's the attraction is half wrench and half blade. I dont think he is use them just for the steel. Wrench knives seam to be popping up all over lately, if I was going to do it I would split the edge and forge weld a bit into it of a high carbon "known" steel.
 
"why not use good known steel to start with" Again, I do. For other blade styles.
"not on par with good cutlery steels" Using a wrench or a railroad spike may not stack up well against other steels, specifically ones ideal for knife making. That does not mean that it doesn't make a suitable knife for the intended purpose. You could say that 5160 or 1075 are absolute garbage compared to something like 3V, M4, D2, etc although both make great knives. My customers know what they are getting and have been happy with their blades.
"I would think that if one was wanting to make a knife, they'd want to make the absolute best knife they could." The market for $1,000+ knives is much much smaller than the market for <$150 knives. You are setting up a false dichotomy where you either only make super high end blades or you only make rustic functional art (which I gather you feel is unacceptable?). I can can do both and everything in between at the same time, appealing to a variety of markets.
 
Exactly. People like that it started out as something other than a knife. If you can get the forge weld down pat, that would be the best of both worlds. Not sure if the alloys would hinder that process at all. I have seen some guys that do it w/ railroad spike handles and a 1095 blade.
 
Whose brand wrenches are you using? It would be interesting seeing a snap-on/wright/proto quality wrench vs the typical no-name Chinese/Indian wrenches that you can buy for pennies.
 
Westward makes some pretty good wrenches and sockets too, for those who can't justify Snap on or other high end wrenches. Craftsman and mastercraft aren't what they used to be a couple decades ago.
 
For the performance question, if you have a Rc tester, start at 1450, and go up increments of 25f or so untill hardness drops off again. I would suggest a 15 to 20 min soak to get everything into solution too. Once you find the sweet spot, you can fine tune by going up or down by 10f to see if you can get better numbers.

Unfortunately, this will need to be done for different brands, and likely even different ages as steel types can change from one batch to the next.
 
I have used some craftsmen, both American made and the ones made over seas as well. Also some Pro-Grade and Tool Shed. Haven't noticed much difference so far. The American made craftsmen might have been a little better, but it is hard to say. Finally got a hold of someone about the Tool Shed ones and they are 31Crv3. I may start spamming the various companies and see if I can get more data on steel types they use.
 
Unfortunately, I don't have a good way to test hardness other than how it acts on the grinder. May grab some testing files soon.
 
Great thing about using craftsman wrenches is now your blade has a life time warranty :rolleyes:
 
You must log in or register to reply here.
Back
Top