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Plate Flange Material Grade Equivalency
ASTM and EN material designation systems use different grade names for chemically and mechanically equivalent steels. This tool shows the correct ASTM and EN equivalents for plate flange service, with application guidance and temperature limits. PMI testing is still required to confirm grade equivalence in a mixed-standard piping system.
PMI Requirement: EN and ASTM grade names define compositional requirements, not material identity. On mixed-standard projects, Positive Material Identification (PMI) testing — X-ray fluorescence or optical emission spectroscopy — is required to confirm that received material meets the specified grade. Synbase provides PMI testing on request, typically covering 10 to 100% of items depending on project QA plan requirements.
Complete Material Grade Reference — Plate Flanges
| Material Category | ASTM / ASME Grade | EN Grade (Number) | EN Grade (Name) | Typical Application | Max Temp. (°C) |
|---|---|---|---|---|---|
| Carbon steel — forged | ASTM A105 | 1.0460 | C22.8 / P250GH | General service, oil and gas utility, flanges requiring good machinability | +450 |
| Carbon steel — plate | ASTM A36 / A516 Gr.70 | 1.0037 / 1.0345 | S235JR / P265GH | General structural / pressure vessel service; plate flange blank stock | +350 |
| Carbon steel — elevated temp. | ASTM A182 F1 (C-½Mo) | 1.5415 | 16Mo3 | Boilers, pressure vessels, steam service to 530°C | +530 |
| 304 Stainless steel | ASTM A240 Gr.304 / 304L | 1.4301 / 1.4307 | X5CrNi18-10 / X2CrNi18-9 | Chemical processing, food and beverage, pharmaceutical; 304L for weld-sensitive applications | +400 |
| 316 Stainless steel | ASTM A240 Gr.316 / 316L | 1.4401 / 1.4404 | X5CrNiMo17-12-2 / X2CrNiMo17-12-2 | Marine, chloride environments, pharmaceutical; 316L for weld-sensitive service | +400 |
| Duplex stainless | ASTM A240 Gr.2205 (UNS S31803) | 1.4462 | X2CrNiMoN22-5-3 | Offshore topsides, seawater, chloride-rich process environments; PREN ≥ 35 | +280 |
| Alloy steel — Cr-Mo | ASTM A182 F11 | 1.7335 | 13CrMo4-5 | Petrochemical reactor service, high-temp steam piping; hydrogen service per API 941 | +550 |
| Alloy steel — 2.25Cr-1Mo | ASTM A182 F22 | 1.7380 | 10CrMo9-10 | Power plant superheater headers, hydrocracker service; good creep resistance to 580°C | +580 |
| Alloy steel — 5Cr-½Mo | ASTM A182 F5 | 1.7362 | X12CrMo5 | Refinery service, high-temp process streams with sulfur; corrosion-resistant alloy service | +600 |
Synbase manufactures plate flanges in all grades listed above. EN 10204 3.1 MTC standard; 3.2 (TÜV witnessed) on request. PMI testing, heat number traceability, and grade equivalency documentation available for mixed-standard projects.
Request a Quote — Specify Grade Requirements
