I realized as I was writing about the stanley irons earlier that I’ve never seen an actual spec sheet for CR60V or CRV-60 or any other iteration of those letters used on tools that come from overseas.
So, I figured that as common as it was, there would be a standard composition, perhaps one of a Chinese spec or a European spec, but I come up empty.
All I can see of it is that it’s anticipated to temper from 58-60 if it’s hardened properly.
Which….is no surprise, because that’s pretty much the exact range that a lot of the low cost imported chisels hit.
I’ve assumed that it is a 0.6% carbon steel with an uptick in manganese and carbon with a little vandium. The middle two make it easier to harden the steal, and the last makes it hard for the steel’s grain to grow. Without anything other than carbon and manganese added to iron, the grain can grow wildly in 15 seconds of moderate to significant overheating. When I’ve subjected 80crv2 steel to even more overheating than that, I see no increase at all in grain size. If the exercise were stretched out further, we would see it.
Vanadium is good at this. Chromium also seems to be protective, but probably not as much. 1084 is the only steel that I can think of where the trusty shop method of thermal cycles and then a quick temperature overshot requires more discretion on the overshot. No problem, you remember it and do it.
But, I can answer that question for 80crv2. I can answer it for SAE6150, which is what folks sometimes think is the “only” chrome vanadium steel. I can answer it even for O1 when there’s an addition of vanadium as is sometimes the case -that is also a steel with chromium and vanadium.
But I guess I’ll have to admit that the low cost tools that come labeled as 60crv or any other similar name, maybe we just won’t know the composition, and I’ll still assume that it’s 0.6% carbon, but won’t know.
Theirs vs. Ours
They being everyone other than the US. SAE 6150 appears to be used in a lot of tools, like sockets and various bits and all manner of things. It’s got a serious increase in manganese and chromium over something like 80crv2. I don’t know why this is, but would guess that it has to do with trading more and more of the content to manganese and chromium in favor of making the steel easier to harden.
I don’t think we see much of it in woodworking tools on the market now, but who knows.
in the “theirs” category is a wider range of steels that have chromium and vanadium, but aren’t pushing a percent of composition for each. I’m sure there are reasons for that and would guess as carbon goes up, increasing alloying would decrease toughness. In a steel like 6150, carbon ranges from a little below to a little above 0.5. Since this stuff is everywhere in wrenches and sockets, it’s obviously useful. I just doubt it would be useful in woodworking tools and wonder if some of the reputation for Chrome Vanadium steels being though of as shiny and gummy is because it was tried in site tools.
Whatever the case is, I guess we’re guessing. 80crv2 is as low as I care for in a steel that’s a little more on the plain side. It’s pushing to get it to temper in the sweet spot around 61.5. It may not sound like much, but hitting that instead of hitting 59 is kind of a big deal. Even then, I’m not sure about its edge stability yet, because it will land around 63 hardness tempered at 350-360F (double tempered even), but the edge won’t be stable for a picky hand tool user. I don’t mean like beginners – I think most of the boutique tool market would be happy with it at high hardness because they are not yet initiated to the fact that harder isn’t better if the edge can’t take advantage of its hardness.
To prove that it’s the hardness and not grain growth, I’ve done a follow up temper to 63 hardness 80crv2 at 400F double tempered. It ends up around 61.5 and the irons are excellent. Whether or not they’re as good or better than O1 would take more follow up and use in actual projects.
That said – if anyone comes across a spec or a cross reference to another spec for “CR-v 60” or anything of the like and it’s more than just a sales listing for screwdriver bits, I’d love to see what the actual composition is.
It could be that like some of the low cost stainless steels, it just isn’t offered for sale to the general public due to lack of interest, and customers for it are more of the “I’ll have a melt of this” rather than “I’ll have two bars”.
Of Making by Hand with Wood and Steel 