Description
Super Duplex F53 & F55 Flanges – UNS S32750 / S32760
A specification-led comparison and supply page for two distinct super duplex forged flange grades. It helps buyers identify the correct ASTM grade and UNS number before requesting manufacture.
Quick engineering answer
ASTM A182 F53 and F55 are separate super duplex forging grades. F53 corresponds to UNS S32750, while F55 corresponds to UNS S32760. They share high strength and strong localized-corrosion resistance, but their chemistry and project approvals differ, so they must not be substituted automatically.
Product specification
| Material | ASTM A182 F53 / UNS S32750 and ASTM A182 F55 / UNS S32760 |
|---|---|
| Available forms | Weld neck, blind, slip-on, socket weld, threaded, lap joint, orifice and drawing-specific flanges where permitted |
| Dimensional standards | ASME B16.5; ASME B16.47 for applicable large diameters; EN 1092-1 or approved drawings on request |
| Pressure classes | Class 150, 300, 400, 600, 900, 1500 and 2500 within the selected standard, material group and size limits |
| Facing | Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF) where permitted, or drawing-specific facing |
| Documentation | EN 10204 3.1 MTC, heat-number traceability, dimensional report and ordered inspection records |
Pressure-temperature ratings depend on the governing code, flange standard edition, material group, size and class. Confirm the complete project specification before ordering.
Grade and terminology check
| Procurement grade | ASTM A182 F53 | ASTM A182 F55 |
|---|---|---|
| UNS designation | S32750 | S32760 |
| Common EN number | 1.4410 | 1.4501 |
| Selection rule | Use when the approved project specification calls for F53/S32750 | Use when the approved project specification calls for F55/S32760 |
Material selection
Use the exact grade stated in the piping material specification. F55 includes intentional copper and tungsten additions compared with F53, but material selection still depends on the process environment, temperature, fabrication route and project qualification—not on a simple higher-grade assumption.
Matching-material note: Coordinate forged flanges with pipe and fittings in the exact approved UNS grade. Confirm solution heat treatment, phase balance, welding controls and any ASTM A923, ferrite or project-specific corrosion-test requirements.
Quality controls available
- PMI and heat-number traceability
- Ferrite or phase-balance verification when ordered
- ASTM A923 or project corrosion testing when specified
- UT, PT and dimensional inspection to the ordered scope
Typical applications
Applications are selection cues, not blanket approvals. Process media, pressure, temperature, corrosion data, fatigue, fabrication and code requirements govern final suitability.
Standards hierarchy
Information required for quotation
Provide the material grade, flange type, standard and edition, NPS or DN, pressure class or PN rating, pipe schedule or exact bore, facing and finish, quantity, delivery destination, heat treatment, NDE, testing, certification and third-party inspection requirements.
Frequently asked questions
Are F53 and F55 the same material?
No. Both are super duplex stainless steels, but F53 is UNS S32750 and F55 is UNS S32760. Purchase orders, MTCs and material traceability must show the exact required grade.
Can F55 replace F53?
Only with written engineering and project approval. A higher alloy designation does not by itself prove compatibility with the design code, welding procedure, adjoining components or service environment.
What should an RFQ include?
State F53/S32750 or F55/S32760, flange type, standard and edition, size, class, facing, bore or pipe schedule, quantity, testing, certification and inspection requirements.
Request a specification review and quotation
Send the complete RFQ or piping material specification. SASA FLANGE will review grade identity, dimensions, facing, inspection and documentation before production.
Related products and engineering resources
ASTM A182 F53 Super Duplex 2507 Weld Neck Orifice Flange ASTM A182 F55 UNS S32760 Weld Neck Orifice Flange Duplex Stainless Steel Material Center
