Rule for ASTM Designation 2

[Xeros]

Hi,
I’m Xeros.

In accordance with ASTM, there are many ASTM designations.
For example, A240 TP 316 is plate product of 316 SS and A387 GR.11 is plate product of 1.25Cr-0.5Mo.

However, I can’t understand the rule for ASTM designation.

I have two question.

1st,
Is there any classification rule for A240, A516 and A387 for plate product? I think that they mean plate product, samely.

2nd,
What’s the difference between type, grade and class?
In case of 316 SS, ASTM designation is A240 TP316 for plate, A312 GR. TP316 for piping, A182 GR. F316 for forging and A358 GR. 316 for Electric Fusion Welded Pipe.

Best regards,

 

[EdStainless]

The things that you are seeing are largely a result of history, not a grand plan.
All alloys should be referred to by their UNS number. This is the real grade designation. In specs there will also be a common name. If there is a commonly used name that imparts no competitive advantage then it will be listed. These name may well vary by product form.
In short, use UNS numbers.

= = = = = = = = = = = = = = = = = = = =
Still trying to help you stop corrosion.
formerly Trent Tube, now Plymouth Tube
eblessman@plymouth.com
or edstainless@earthlink.net

 

[JasonLouie]

Hi Xeros,
This is my understanding of ASTM:
1. The ASTM numbers are numerical in order. The lower the number, the older the original specification.

2. I believe TP does not mean "type". I was told it was used to indicate tube or pipe material, just like F is used for forgings.

 

[metengr]

Yes, TP is not Type, it denotes tube/pipe product forms.

 

[Xeros]

Thanks, Everybody

I have more questions.

1. In case of 1.25Cr-0.5Mo forging product, there are A182 Gr.F12 and. A336 CL.F12
What's the difference in meaning or rule between Grade (Gr.F12) and Class (CL.F12)??

2. A240 TP304 means 304 SS plate product. I think "TP" is type of material in this case.
JasonLouie and metengr said "TP" means tube/pipe product.
Is "A240 TP304" a wrong Designation for 340 SS plate product?
What is correct Designation, If this is wrong.


Best regards,

 

[metengr]

Xeros;
Regarding your first question, Grade refers to a specific chemical composition that falls under a family of alloys. For example, Cr-Mo alloys can contain various Grades, like 11, 22, etc. In this case, Grade refers to a specific alloy chemcial composition.

In general, Class usually denotes a specific fabrication condition associated with a particular Grade of steel. For example, for seam welded pipe, you can have one Grade of steel plate that is used to form the pipe, however, you can have various heat treatments (strength levels) and tests during fabrication that are identified by Class.

Yes, this sounds complicated. However, the best way to learn this is to read various ASTM/ASME specifications for the product form of interest.

 

[metengr]

2. A240 TP304 means 304 SS plate product. I think "TP" is type of material in this case.
JasonLouie and metengr said "TP" means tube/pipe product.
Is "A240 TP304" a wrong Designation for 340 SS plate product?
What is correct Designation, If this is wrong

Sheet or plate are used to form welded tube or pipe products.

 

[JasonLouie]

As I was told by a very good instructor, "Always go back to the spec and read it."

If you look in A240, there is no mention of "TP". Table 1 lists "Type" as a grade designation originally assigned by AISI. A312 uses "TP" for the various grades. I have seen many brochures and people using TP - I believe because they think it stands for type. This is similar to, but not really, to the use of BHN (my personal beef). Nowhere does ASTM E10 use BHN but it is in company specs and brochures everywhere.