Description
Type 410 martensitic stainless high-temperature bolting
ASTM A193 B6 410 Stainless Stud Bolts
ASTM A193 Grade B6 fully threaded Type 410 stainless stud bolts supplied with the required heat treatment, dimensions, matching nuts, surface condition and inspection records.
Quick answer
ASTM A193 Grade B6 is a heat-treated martensitic stainless-steel bolting grade associated with Type 410 stainless steel. It combines high strength with chromium-based oxidation and corrosion resistance for high-temperature or special-purpose joints specified by the design.
Product at a glance
What are ASTM A193 B6 stud bolts?
ASTM A193 B6 stud bolts are manufactured from a hardened-and-tempered martensitic stainless grade associated with Type 410. Unlike austenitic grades such as 304 or 316, B6 is magnetic and its heat treatment is central to obtaining the required mechanical properties.
The chromium content provides oxidation and moderate corrosion resistance, but B6 is not a universal substitute for 316 stainless or nickel alloy in aggressive media. The process fluid, temperature, galvanic couple, gasket, nut grade and cleaning or passivation requirements must be reviewed together.
ASTM A193 B6 stud bolt specifications
| Material | Type 410 martensitic stainless steel |
|---|---|
| Heat treatment | Hardened and tempered to ASTM A193/A193M Grade B6 |
| Configuration | Fully threaded flange stud; double-end options by approved drawing |
| Threads | UNC, 8UN or project-specified series and class to ASME B1.1 |
| Dimensions | ASME B18.31.2, flange bolting schedule or approved drawing |
| Matching nuts | ASTM A194/A194M Grade 6 when specified and compatible |
| Finish options | Plain machined, cleaned or passivated as specified; coating by approval |
| Documentation | MTC, heat treatment, hardness, mechanical tests, PMI and dimensions as ordered |
Final dimensions, heat treatment, class or grade properties, coating, testing and acceptance criteria follow the purchase order and contractually required standard edition.
Why specify this grade?
Specify B6 when the approved design requires martensitic Type 410 stainless bolting for elevated-temperature strength, oxidation resistance or compatibility with the selected equipment material system.
Critical engineering note
B6 should not be selected solely because it is called stainless steel. Its corrosion resistance, hardness, tempering condition, stress-corrosion behaviour and compatibility with nuts and mating components must be verified for the actual environment.
Stud, nut and finish options
Typical applications
Quality, inspection and documentation
B6 identification can be supported by PMI, hardness testing and full heat-treatment traceability. Surface cleanliness and passivation documentation are added when required by the purchaser.
- EN 10204 3.1 material test certificate when ordered
- Heat-number and batch traceability from raw material to finished stud
- Chemical composition and mechanical-property records
- Heat-treatment record and hardness test results
- Dimensional inspection and calibrated thread gauging
- PMI when specified for chromium or A-286 alloy identification
- Surface, coating or passivation inspection as applicable
- Third-party inspection, marking and export packing by agreement
Information required for quotation
- ASTM standard, exact grade or class and required edition
- Stud diameter, overall length, thread series and thread class
- Matching nut specification, grade or class, style and quantity
- Design and operating temperatures plus any cyclic or upset conditions
- Plain, passivated, coated or plated finish and approved process
- MTC, PMI, hardness, tensile, coating and third-party inspection requirements
- Applicable piping code, equipment specification and owner supplements
- Quantity, delivery destination, packing method and required schedule
Frequently asked questions
What material is ASTM A193 B6?
B6 is a heat-treated martensitic stainless-steel bolting grade associated with Type 410 stainless steel.
Is B6 stainless steel magnetic?
Type 410 martensitic stainless steel is normally magnetic. Magnetic response alone is not an acceptance test for ASTM A193 B6 compliance.
Which nuts match B6 stud bolts?
ASTM A194 Grade 6 heavy hex nuts are commonly specified. Confirm nut properties, dimensions, finish and service compatibility in the purchase order.
Does B6 have the same corrosion resistance as 316 stainless?
No. B6 and 316 have different alloy systems and corrosion behaviour. The process environment must be reviewed before selecting B6.
Related stud bolt products
Reference standard
Material and class requirements are controlled by ASTM A193/A193M. Thread form and stud dimensions may reference ASME B1.1 and ASME B18.31.2. State the contractually required edition in the purchase order and review all supplementary project requirements.
Request a technical quotation
Send the grade or class, bolting schedule, nut requirement, service conditions, inspection plan and delivery destination for technical review.
