ASTM A105 is the default carbon steel for forged pipe flanges, a plain carbon-manganese grade for ambient and elevated-temperature pressure service. A105N is the same steel supplied in the normalised condition, which some specifications require and some do not.
A105 is a material specification, not a shape: the flange geometry still comes from ASME B16.5, EN 1092-1, DIN, GOST or your drawing, in the usual Class 150 to 2500 or DN and PN ratings. What the A105 requirement actually controls is chemistry, mechanical properties, heat-treatment condition and what the certificate has to say.
So the enquiry needs two halves: the dimensional half - type, standard, size, class, facing - and the material half, meaning A105 or A105N and whether normalising is called out. Verification is a chemical and mechanical certificate check against the grade, a dimensional check against the table, heat-number marking and hardness where specified, with MTC 3.1 as the standard document and third-party inspection on request.
Product family: Flanges
ASTM A105 flange RFQs are reviewed for standard, class, size, heat treatment, MTC, marking and inspection requirements.
| Scope and rating | |
|---|---|
| Shape scope | The flange shape still follows ASME, EN, DIN, GOST or drawing; A105 controls material certificate and heat treatment. |
| Standards and materials | |
| Standards / drawings |
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| Material grades |
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| Geometry, tolerance and inspection | |
| Typical ratings | Common ASME Class 150 to 2500 line items, with PN/DN projects reviewed by drawing and material note. |
| Critical documents | MTC 3.1, heat number traceability, normalizing note when required, hardness and dimensional report. |
| Inspection depth | Chemical/mechanical certificate check, dimensional table check, marking and third-party inspection by project request. |
| Reviewed before quotation |
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| Buying logic | |
| Best-fit RFQ | Best for carbon steel forged flange RFQs where ASTM A105 or A105N is specified. |
| Buyer application | General pressure piping, refinery, petrochemical, water, power and industrial flange packages. |
Your standard, drawing revision and project specification govern.
Also known as
We confirm each step against your drawing or standard before we quote.
Material grade, heat number, certificate basis and substitution limits are checked against the ASTM A105 Flanges drawing or standard before procurement is released.
The forging route is selected around flange type, section thickness, bore allowance, hub or neck geometry and pressure-service requirements.
Heat treatment is planned with the required record package, mechanical testing basis and impact-test condition where low-temperature or alloy service applies.
Rough machining opens reference faces, bore, hub, neck or sealing-face stock needed to control allowance before final flange machining.
Final machining controls facing, bore, bolt pattern, groove, sealing surface and flange-table or drawing tolerances before dimensional inspection is issued.
Inspection covers dimensional report, MTC 3.1, PMI and required UT, MT or PT records before the release documents are matched to the purchase order.
Marking, packing and export documents are prepared by PO line item so the ASTM A105 Flanges shipment can clear customs and be identified at site receiving.
List document requirements in the first RFQ; they affect price and schedule.
No. A105 is a material specification, not a shape: the geometry still comes from ASME B16.5, EN 1092-1, DIN, GOST or your drawing, while A105 controls chemistry, mechanical properties, heat-treatment condition and what the certificate has to say.
No. A105N is the same steel supplied in the normalised condition, which some specifications require and some do not, so tell us whether normalising is called out.
Ambient and elevated-temperature pressure service. ASTM A350 LF2 is the grade used when low-temperature service and impact-test evidence are part of the RFQ basis.
Yes. SA-105 is listed in Annex I of TÜV NORD certificate CER-IND1105842412004001 Rev. A, which covers our materials certified to ASME Section II Part A by TÜV NORD. Each order's own heat is still reported on its MTC 3.1.
Email quote@bldforgedirect.com with standard, drawing, material, quantity and inspection requirements.