Standards guide
ASME B16.5 Flange Class Rating
How to specify carbon steel and stainless steel flanges.
Practical Standard Review
Flange orders should confirm standard, material grade, class, size, facing, bore, hub, finish, coating, marking, and certificate. Class rating is not a stand alone pressure value.
Himount Steel reviews the ordered standard, grade, product form, dimension tolerance, inspection level, packing method, and shipment route before confirming price and lead time. Final supply always follows the buyer specification and accepted mill test certificate.
Key Ordering Points
| Main comparison | Flange orders should confirm standard, material grade, class, size, facing, bore, hub, finish, coating, marking, and certificate. Class rating is not a stand alone pressure value. |
|---|---|
| Confirm in RFQ | ASME B16.5 or B16.47, class, size, material, face type, bore, finish, and MTC |
| Risk to avoid | Confirm facing and bore before machining; later changes can delay shipment. |
| Documentation | Confirm MTC type, heat number traceability, inspection record, and any buyer approval wording. |
| Next step | Send the project specification or previous PO so Himount Steel can check the supply route. |
Buyer Checks Before Quotation
- Use the project specification as the authority when grade names look similar.
- Confirm product form, size, tolerance, delivery condition, and inspection plan together.
- Ask for comparable references only as RFQ aids, not automatic substitutions.
- Review certificate wording before shipment if the project has strict acceptance rules.
Related Himount Pages
Prepare A Complete Steel Inquiry
Send the product standard, grade, size list, quantity, drawings, inspection scope, certificate request, packing method, and destination port. Himount Steel will review the technical route before quotation.