In a word, no. Nothing is ever “just like”, especially in steel.
Today, I had to source some small diameter 17-4 (less than three inches in diameter is small to me), double heat treated to H1150. In the steel world that I live and breathe from 8AM to when I leave the ol’ officina, that’s called 17-4 DH1150 ( shout out to those that have gone before me and call it 630 round bar!).
Honestly, I couldn’t find the weight needed, about 2500 lbs or so, already treated, but I did find some annealed bar that could be treated to DH1150. So I offered it to sales, suggested to get it treated and we’d still be in the good. Pretty freaking awesome for just before 10 AM, if you ask me.
Well, in the request for quote, there’s all this stuff that the material needed to be, hardness properties, tensile, yield, etc. No big, right? I mean, we are going to pay to get it there. Still, pretty freaking awesome for just before 10AM.
Mid day, the email comes to me, I see the ghost pop up on my screen, and there it is — “Customer wants to know if its gonna be JUST LIKE this” . the referenced “THIS” is an tolerance of +/- 0.002. Yes, plus or minus 0.002″ on the bar.
My bars are to ASTM A484 and have a cold finished tolerance of + / – 0.003″. That’s the standard, and finishes (cold finished or hot rolled rough turned) typically follow those ASTM standards on tols. (I’ll tellya all about machining allowances at a later time — that’s a hella explanation, even for me).
I explained to sales the ASTM 484 thing, and realized while discussing this very small difference, I came away with knowing, that, nope, it’s not “gonna be just like”.
I’m glad I live in Texas, where we have “the same, but different” attitude.