Fastener grades
Stud and nut specifications for every flange material, from B7/2H to titanium and nickel alloys.
Bolting grade table
| Material | Stud | Nut | Min tensile / yield, MPa | Typical use |
|---|---|---|---|---|
| Alloy steel | ASTM A193 B7 | ASTM A194 2H | 860 / 720 (to 2½ in) | General refinery and plant flange bolting |
| Alloy steel, sour service | ASTM A193 B7M | ASTM A194 2HM | 690 / 550 | NACE MR0175, hardness 235 HB max |
| Cr-Mo-V, high temperature | ASTM A193 B16 | ASTM A194 4 / 7 | 860 / 725 (to 2½ in) | Steam and hot service |
| Low temperature | ASTM A320 L7, L7M, L43 | ASTM A194 7 / 7M | 860 / 725 (L7) | Impact tested to -101°C (L7) |
| Stainless 304 / 316 | ASTM A193 B8, B8M Cl.1 and Cl.2 | ASTM A194 8, 8M | 515 / 205 (Cl.1) | Strain-hardened Cl.2 for higher strength |
| 904L and 254 SMO | ASTM B649 bar | ASTM B649 bar | Per bar spec | Acid and chloride service |
| Duplex and super duplex | ASTM A1082 / A276 S31803, S32205, S32750, S32760 | Matching grades | Per grade | Seawater and offshore |
| Titanium Gr 2, 5, 7 | ASTM F468 / B348 | ASTM F467 | 345 / 275 (Gr 2); 895 / 828 (Gr 5) | Seawater and chlorine |
| Nickel alloys | B446 (625), B637 (718), B574 (C276), B164 (Monel 400), B865 (K-500) | ASTM F467 equivalents | Per alloy | Acid, sour and high-temperature service |
Matching flange materials
Have a BOQ or drawing? Get a quotation from the manufacturer.
Send sizes, grades and quantities. Our estimation team usually replies within one working day.
Threads, marking, testing and coatings
Threads
UNC up to 1 inch and 8 UN from 1⅛ inch, class 2A/2B, per ASME B1.1. Metric ISO threads on request. Threads rolled or cut.
Marking
Studs and nuts stamped with grade symbol and Teshi mark, and heat lot traceable to the test certificate.
Testing
- Tensile, yield and hardness per grade
- Proof load on nuts
- Impact tests for L7 and LTCS grades
- PMI on alloy bolting
Coatings and packing
Plain, hot-dip galvanised, zinc-nickel, PTFE (Xylan-type) and others. Packed in boxes or bags by size, labelled per joint set on request.
Questions buyers ask
When should I use B7M instead of B7?
Use B7M with 2HM nuts where the specification calls for sour (H2S) service under NACE MR0175. B7M has a hardness limit that lowers its strength compared with B7.
Get a quotation from the manufacturer
Send your BOQ, drawing or tender reference. You deal directly with the manufacturer.
- Reply from our estimation team, usually within one working day
- Carbon steel to titanium on one order
- EN 10204 3.1 or 3.2 certificates, third-party inspection welcome
- ISO 9001:2015 certified and IBR approved, since 1971
Drawings and BOQ spreadsheets are easiest by email. Mention your project name.