ASTM A-234/A-234M – Material inspection and review MTC

Order information

  • Quantity,
  • Description of fitting and nominal dimensions (standard or special),
  • Steel composition by grade and class designation,
  • Construction, seamless or welded (unless seamless or welded construction is specified by the purchaser, either may be furnished at the option of the supplier),
  • Specification number (including the year/date of issue),
  • Supplementary requirements, and
  • Additional requirements. 



The pipe fittings were formed from stock bar, plate or pipe to size, by cold forming or hot forming.


When specified in the project specification, the MTC of raw material must be attached together for reviewing.

  • If pipe fitting was formed from stock bar, the MTC of stock bar must available for reviewing.
  • If pipe fittings wrought from the seamless pipe, the MTC of pipe must available for reviewing.

So, the MTC of pipe fittings will include of material test certificate (as per ASTM A234) and raw material certificates (stock bar or seamless pipe).

Example: your fittings manufactured by Thai BenKan, but the seamless pipe manufactured from Nippon Steel. So, one MTC as below is not enough. That MTC should include the MTC of Nippon Steel's Pipe to update the RAW MATERIAL CERIFICATES.

Sample MTC

Product marking are acceptable accordance to ASME B16.9 as photo

Manufacturer: yes

Specification: yes

Dimension: yes

Trace number: yes


Who is finished to size or shape.

Product marking is company name, logo or trade-marks.

Trace number

Also called heat number, ladder number (L), cast number declared in the MTC. The trace number is traceability to all the test results such as chemical analysis results, mechanical test results, etc. The marking code also accept in the MTC by process manufacturer which they assigned another making code under company quality manual control.

Product marking is heat number or cast number (example 13D00014)


A material specification, in the MTC should have year of edition.

Product markings is specifications number such as ASTM A234 WPB or WPBW (read more ASTM A234 table A1.1)

Dimensions and tolerance

The fittings are accordance to ASME B16.9. Steel socketwelding and threaded fittings purchased in accordance with this specification shall conform to the sizes, shapes, dimensions, and tolerances specified in the latest revision of
ASME B16.11, MSS-SP-79, or MSS-SP-83.
Learn more: identification marking acc. to ASME B16.9.

Mechanical properties

The material shall conform to the mechanical property requirements prescribed in Table 2, yield strength and percentage of elongation, hardness value.

Note: if material requirement to comply with NACE, must be noted at hardness value and heat treatment, read more NACE MR0175.

Chemical analysis

​​​​Heat analysis and/or product analysis. Some MTC stated heat analysis (H) and/or product analysis (P) refer to ASTM A234 table 1.Tolerance refer to ASTM A960.

Note: Chemical compositions may be tranferred from pipe's MTC.

Product marking is heat number or heat code.

Heat treatment

Heat-treated fittings shall be treated according to paragraph 7 in Specification A 960/A 960M.

Product marking is not required

Learn more: inspection material compliance with NACE MR0175


Hydrostatic tests is not required.

Read more: ​re-test or upgrade material for pipe fitting.


The supplementary requirements shall apply only when specified by the purchaser in the inquiry, contract, and order such as CE%, hardness, heat treatment, NDE after forming, etc.

Nguyen Duy Bien

Enjoy learning and researching, reading book. Knowledge welding inspection painting inspection.

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