Hardness not up to spec 1

[Ryan9]

I received some material and checked the harness of it. It is 4130 annealed, which from what I can tell is suppose to be 82 HRB. It checks out to be 64 HRB. Is this with in spec? what should I do with this?

 

[jaxhokie]

If you ordered it to a certain specification, typically the specification will give you a range of hardness values that are acceptable. There should also be tolerances specified in the specification or a referenced specification.

 

[Ryan9]

the specs were not given to the supplier, he gave them to me, I told him I needed 4130 condition A. The spec is AMS 6350H 2301G ASTM A506. I found the ASTM A506 report, but don't know where to find the other reports. That's my dilema, I can not find what those tolerances are.

 

[gdodd]

According to SAE standard J1397 "Estimated Mechanical Properties and Machinability of Steel Bars" your 4130 should have a hardness of 187 to 229 HB. That is 90.7 to 98 HRB. I think if the hardness of your sample is 62HRB you might have the wrong material or it is badly decarburised.

 

[Ricko]

I agree with gdodd. I reviewed AMS 6350 and it only specifies a maximum hardness in the annealed condition....no minimum -- though the value you have does seem low for 4130 Cond A. Have the steel chemistry checked by the supplier.

 

[bobn]

;You don't say how big the piece is. If it is a forging or large rolled section, decarburization could be the problem. Annealing at high temperature for a long time can do it too. Try grinding deeper and take another test. There are minimum stock removal tolerances on Hot Rolled Bars for this reason.
Bobn