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BLD Forge Direct

ASTM A105 vs A350 LF2 Flanges

ASTM A105 and ASTM A350 LF2 are both common forged flange materials, but buyers should not treat them as interchangeable. Service temperature, impact testing, heat treatment, standard route and certificate requirements should be confirmed before quotation.

Summary for Buyers

ASTM A105 and ASTM A350 LF2 are both common forged flange materials, but buyers should not treat them as interchangeable. Service temperature, impact testing, heat treatment, standard route and certificate requirements should be confirmed before quotation.

Use A105 for common carbon steel flange requirements when project conditions allow

Use A350 LF2 when low-temperature service and impact testing are specified

Confirm normalized condition, certificate wording and inspection documents

Attach the project specification when material selection is controlled by the end user

Practical Checklist

Use this list before sending drawings or line items for quotation review.

Project service temperature and material specification

Flange standard, pressure class, size and facing

A105, A105N, A350 LF2 or other required material wording

Heat treatment, impact test and low-temperature test requirements

MTC 3.1, chemical and mechanical values, and heat number traceability

PMI, UT, MT, PT or third-party inspection if required

Destination country and any end-user approval requirement

Common RFQ Mistakes

These points often cause repeated clarification, price revisions or document mismatch.

  • Using A105 for low-temperature service without checking the project specification
  • Not stating whether A105N or normalized condition is required
  • Requesting A350 LF2 but omitting impact test or certificate requirements
  • Mixing material names with ASME, EN or GOST dimensions without a clear standard route
  • Comparing prices without checking heat treatment and document scope

Send RFQ for Review

Attach drawings, standards, material grades, quantity, inspection requirements and destination details for direct review.

Send your RFQ or drawing directly to BLD Forge Direct.

Email [email protected] with standard, drawing, material, quantity and inspection requirements.