Steel Materials Catalog
Every Grade Of Steel A Flange Should Be Made From.
Steel Flange is built around one idea: the full steel range, one phone number, one set of mill test reports. Forged A105 and A350 LF carbon, plate-cut A36 and SA-516-70 blanks, austenitic 304 and 316 stainless, chrome-moly F11 through F91, and the nickel alloys, duplex, and super duplex that cover the corner cases. One distributor, full documentation.
Four Steel Families. One Source.
Material picks pressure rating, temperature ceiling, corrosion life, and welding procedure. Every steel flange and fitting we supply falls into one of four families. Get the family right first, then narrow to the grade.
Carbon Steel
A105 forged flanges from 1/2 inch through 96 inch, A350 LF2 and LF3 for low-temperature service, SA-516-70 and A36 plate for cut-blank work, and the full A694 high yield range F42 through F70 for transmission pipeline.
Stainless Steel
Austenitic F304/304L and F316/316L cover the bulk of the work. F321 and F347 handle elevated temperature. SA-240 plate available for plate-cut stainless rings, blinds, and AWWA configurations.
Chrome-Moly Alloy
F5, F9, F11, F22, and F91 (Grade 91). The chrome-moly grades that hold pressure rating at 1000F and above, fight hydrogen attack, and earn their keep in refinery and supercritical power plant piping.
Exotic Alloys
Hastelloy C-276 for severe chloride, Inconel 625 and 825 for sour and seawater, Monel 400 for HF and brine, duplex 2205 and super duplex 2507 for offshore and pulp mill service.
Four Questions That Pick The Steel
Most material disputes on a job come from skipping one of four questions. Walk through them in order and the spec sheet usually writes itself.
1. What is the design pressure and temperature?
ASME B16.5 pressure-temperature tables drop sharply with temperature. A105 derates fast above 500F. F22 holds rating up around 1000F. F91 takes you into supercritical steam territory. A694 earns Class 600 and above through heat treatment.
2. What is the fluid and how corrosive is it?
Chlorides push you to 316L minimum and often to duplex. Wet sour service triggers NACE MR0175 hardness limits. HF alkylation service is Monel territory. Plain water rarely needs more than coated carbon.
3. What code governs the system?
ASME B31.3 process piping, B31.1 power, B31.4 liquid pipelines, B31.8 gas transmission, and AWWA for water each impose their own material rules. The code chooses the spec before the designer does.
4. What is the minimum design metal temperature?
A105 is good to roughly -20F without supplementary impact testing. LF2 takes you to -50F, LF3 to -150F, and austenitic stainless covers cryogenic without a second thought.
Forged Versus Plate-Cut
Standard ASME B16.5 flanges through 24 inch are typically forged from A105 or the equivalent stainless and alloy bar. Above 24 inch, and on AWWA and other waterworks configurations, plate-cut from SA-516-70 or A36 is the usual route. Both serve the same function. The cut-plate path opens up larger sizes, non-standard drilling patterns, and custom thicknesses without tooling cost.
For a deeper read on how to pick the right grade for the service, see the grade selection guide in our technical resources library.
Not Sure Which Steel You Need?
Send us the line spec, the service conditions, or just the drawing. We will come back with a material recommendation and a quote, usually the same business day.