Stainless steel stud bolts: B8 and B8M
ASTM A193 B8 (304) and B8M (316) studs, Class 1 solution treated or Class 2 strain hardened, with matching nuts.
About stainless stud bolts
Class 1 stainless studs are solution treated and have low strength. Class 2 are strain hardened for much higher strength, often needed to seat gaskets on Class 300 and above. Check your piping class.
Grades
| Grade | Specification | Notes |
|---|---|---|
| A193 B8 / A194 8 | Type 304 | Class 1 or Class 2 |
| A193 B8M / A194 8M | Type 316 | Class 1 or Class 2 |
| B8C, B8T | Stabilised 347 / 321 | High temperature |
Need stainless stud bolts? Get a price from the manufacturer.
Send diameter, length, grade, coating and quantity, or the flange list.
Bolt set finder
Studs and nuts per flange joint, with d, F and H on the drawing.
Bolt set finder
Studs and heavy hex nuts for any number of ASME B16.5 flange joints.
Stud length depends on facing and gasket thickness, so add those in your enquiry.
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
What is the difference between B8M Class 1 and Class 2?
Class 2 is strain hardened after solution treatment, roughly doubling yield strength in smaller sizes. Class 1 is softer but more corrosion resistant in some environments.
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.