Hardness, directly opposite side of stamped parts number 1

[Casper21]

Having a bit of an argument here.
I was always taught not to do hardness directly opposite of the stamped part number.
history:
Material: SAE 1045
part is heat treated to HRC 25-29
thickness is 3.2mm

Yay or nay?

thanks

 

[EdStainless]

Which hardness method?
Are you well within the limits for min thickness?
I wouldn't do it there unless you want to know the effect of the stamping.

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P.E. Metallurgy, Plymouth Tube

 

[CoryPad]

Opposite as in the stamped part number is placed on the specimen support (anvil)? I vote nay.

 

[MintJulep]

It will always be ok to not take the reading opposite a stamped number.

It might be ok to take the reading opposite the stamped number in some cases, depending on:

The material.
The thickness of the material.
The size and depth of the stamping.
Probably so other things.

The concern is likely that stamping might work-harden the material "around" the stamp, and around could include the opposite surface.

In this particular case, assuming the stamp is done before the heat treat, probably it doesn't matter.

As a matter of simplicity, what you were taught is the way to go.

 

[Guest102023]

Read the appropriate ASTM standard for the test method being used, and understand the technical requirements for sample preparation.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[1gibson]

Run the test in both locations. Is there a difference?

 

[Maui]

If you stamp the material, then it will become deformed in that area. Placing that unevenly deformed surface on a testing anvil may cause the part to not sit squarely or flat. And it likely won't be supported properly either. I would avoid placing a stamped surface on the anvil for these reasons. The material may also work harden where it has been stamped, which [italic]might[/italic] impact the readings if the part is relatively thin. You were taught properly.

Maui