Material Grade Reference

ASTM A105

Carbon steel forgings — flanges and forged fittings. A105 is the carbon steel forging grade behind most weld-neck, slip-on, blind and threaded flanges, and behind socket-weld and threaded fittings in 3000 and 6000 LB classes. Where A234 WPB covers wrought fittings, A105 covers the forged side of the same carbon steel line.

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Cross-system equivalents

Cross-system grades are nearest counterparts, not drop-in substitutes. Chemistry and mechanical envelopes overlap but are not identical — where a design code names a grade, order that grade. Final selection should be confirmed by your project engineer against the governing code.

Standard systemGrade designation
ASME / ASTMA105
EN / DINP250GH (1.0460)
JISSF440A
GOSTСт25
GB25#

Where this grade belongs

Where it does not

The failures we see most often are not bad material — they are the right material in the wrong service.

What we supply in ASTM A105

Forms: Weld-neck, slip-on, blind, threaded, lap-joint and socket-weld flanges; couplings, unions, plugs and bosses

Size range: DN15 – DN1500 (1/2" – 60"), Class 150 – Class 2500 / PN6 – PN100

Documentation available

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Frequently asked

What is the difference between A105 and A234 WPB?

A105 is a forging grade used for flanges and forged fittings; A234 WPB is a wrought grade used for butt-weld fittings. They are the forged and wrought halves of the same carbon steel piping line and are routinely used together.

What is the low-temperature version of A105?

A350 LF2, which adds Charpy impact testing at −46 °C. If your design temperature goes below about −29 °C, specify LF2 rather than A105.

Which EN grade corresponds to A105?

P250GH (1.0460) is the counterpart usually referenced for EN 1092-1 flanges.

Related grades

Full cross-reference across all families: Technical Guide § 2 — Material Grade Equivalents. Pressure class and schedule conversion: § 3 — Pressure Ratings & Pipe Schedules.