"Carbon steel" is not enough to quote a flange. Each standard family has its own grades, and the right one depends on the pressure, temperature and code of the project.
ASTM grades (for ASME flanges)
- ASTM A105 – forged carbon steel for ambient and higher-temperature service. The default grade for ASME B16.5 flanges.
- ASTM A350 LF2 – forged carbon steel with impact testing at low temperature, for cold-service piping.
- ASTM A181 – forged carbon steel for general-purpose piping.
EN grades (for EN 1092-1 flanges)
- P245GH and P250GH – steels for pressure purposes at elevated temperature (EN 10222-2 for forgings). Common for PED projects.
- S235JR – structural steel, widely used for type 01 plate flanges in general and low-pressure service.
- C22.8 – traditional DIN forging grade, still found on older drawings.
JIS grades
SS400 is the usual material for JIS plate flanges; SF390A and SF440A are forged steels for hubbed and higher-rated flanges.
How to choose
Follow the project specification first. If there is none, match the material standard to the flange standard (ASTM with ASME, EN with EN 1092-1, JIS with JIS), and add impact testing where the minimum design temperature requires it.
About Hyupshin Flanges
Shandong Hyupshin Flanges Co., Ltd has manufactured forged steel flanges since 1988 and exports more than 90% of its production. Monthly output is about 2,000 tons, with a supply range of DN15 to DN3000. Orders are supplied with EN 10204 3.1 material certificates, and third-party inspection can be arranged. Certifications include ISO 9001, Korea KS, CE PED, UKCA, AD 2000, LRQA.
See the flange raw material data sheets, or send your RFQ, drawing or item list. Minimum order is 1 ton or 100 pieces.