ASTM A193 B8M Stainless Stud Bolts
| Standard | DIN 939 / 835 · ASTM A193 / ASME B16.5 |
|---|---|
| Material | SS316 / 316Ti |
| Strength Grade | B8M Class 2 |
| Size Range | M12-M64 |
| Surface Treatment | Solution Annealed + Passivated |
01
Product Description
Product Description & Key Specifications
ASTM A193 B8M Class 2 stainless stud bolts are supplied in SS316 / 316Ti for pressure flange bolting and corrosion-resistant high-temperature service. Common project range is M12-M64, with DIN 939 / DIN 835 references, ASME B16.5 flange compatibility and solution annealed plus passivated surface condition.
B8M is a molybdenum-bearing austenitic stainless bolting grade used where chloride corrosion resistance is required beyond general B8 stainless service. Class 2 indicates strain-hardened higher-strength bolting according to ASTM A193 requirements, so certificate and mechanical property confirmation are important for procurement.
Stud bolt orders should confirm diameter, thread pitch, overall length, thread engagement, nut pairing, coating or lubricant requirement, heat number traceability and whether ASTM A194 Grade 8M heavy hex nuts are required. For flange joints, the applicable pressure class and gasket stack should be checked by project engineering.
| Product type | Stainless stud bolts / flange stud bolts |
|---|---|
| Standards | ASTM A193 B8M Class 2 / DIN 939 / DIN 835 / ASME B16.5 reference |
| Material | SS316 / 316Ti |
| Strength grade | B8M Class 2 |
| Size range | M12-M64, with length confirmed by flange standard or drawing |
| Common models | M16 x 100, M20 x 120, M24 x 150, M30 x 180, M36 x 220 |
| Thread type | Full-thread or double-end thread by order |
| Surface finish | Solution annealed + passivated |
| Documentation | MTC, heat number traceability, CoC and dimensional report on request |
Dimensions & SpecificationsDIN 939
Technical Drawing
Dimensional Table
| Parameter | M4 | M5 | M6 | M7 | M8 | M10 | M12 | M14 | M16 | M18 | M20 | M22 | M24 | M27 | M30 | M33 | M36 | M39 | M42 | M45 | M48 | M52 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| P | 0.7 | 0.8 | 1 | 1 | 1|1.25 | 1.25|1.5 | 1.25|1.5|1.75 | 1.5|2 | 1.5|2 | 1.5|2.5 | 1.5|2.5 | 1.5|2.5 | 2|3 | 2|3 | 2|3.5 | 2|3.5 | 3|4 | 3|4 | 3|4.5 | 3|4.5 | 3|5 | 3|5 |
| b1 | 5 | 6.5 | 7.5 | 9 | 10 | 12 | 15 | 18 | 20 | 22 | 25 | 28 | 30 | 35 | 38 | 42 | 45 | 50 | 52 | 58 | 60 | 65 |
| ds/max | 4 | 5 | 6 | 7 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 | 24 | 27 | 30 | 33 | 36 | 39 | 42 | 45 | 48 | 52 |
Engineering references
Technical resources
Review the applicable dimensions, drawing and standard relationship before confirming the ordered specification.02
Selection
Selection Advantages by Application
Oil & Gas / Petrochemical Flanges
B8M Class 2 stud bolts are selected for stainless or corrosion-resistant flange bolting in process lines, valves and pressure equipment. M20, M24, M30 and M36 are common RFQ sizes for ASME flange projects.
Oil and gas fastenersOffshore Wind & Marine Renewable Structures
SS316 / 316Ti B8M stud bolts support splash-zone and marine renewable assemblies where chloride exposure and documentation are critical. Confirm nut grade, lubricant and galling prevention method.
Renewable energy fastenersPower Generation Equipment
M16-M36 B8M stud bolts are used for auxiliary systems, stainless flanges and equipment interfaces where corrosion resistance and traceable bolting certificates are required.
Power generation fastenersMarine & Coastal Piping
B8M stainless stud bolts are appropriate for selected marine piping and equipment flanges exposed to wet or chloride-rich environments. Confirm gasket, preload and matching A194 nut requirements.
Marine fasteners03
Assembly
Recommended Matching Products
04
Manufacturing
Manufacturing & Quality Control
Manufacturing CapabilityQuality Control
Thread rolling or machining selected by diameter, length and standardHeat number and SS316 / 316Ti material verification
Solution annealing and passivation by project requirementMechanical property review against ASTM A193 B8M Class 2
Full-thread or double-end stud productionThread gauge and overall length inspection
Stud bolt and nut set packaging for flange projectsMTC, CoC and inspection report prepared on request
Marking and traceability by order requirementPMI, hardness or additional testing arranged when specified
05
FAQ
Common Questions Before RFQ
What does ASTM A193 B8M Class 2 mean?
B8M is a molybdenum-bearing austenitic stainless bolting grade, commonly associated with 316 stainless chemistry. Class 2 indicates a higher-strength strain-hardened condition under ASTM A193 requirements.
What nuts should be used with B8M stud bolts?
ASTM A194 Grade 8M heavy hex nuts are commonly specified with ASTM A193 B8M stud bolts. The final nut grade should follow the flange specification, temperature and project standard.
Are these stud bolts suitable for ASME B16.5 flanges?
Yes, B8M stud bolts are commonly supplied for ASME B16.5 flange bolting. Diameter, length and nut quantity should be confirmed from the flange class, gasket and project specification.
What sizes are commonly requested?
Common RFQ models include M16 x 100, M20 x 120, M24 x 150, M30 x 180 and M36 x 220, but flange projects should confirm length from the applicable standard or drawing.
Can MTC and heat number traceability be supplied?
Yes. MTC, heat number traceability, CoC and dimensional inspection reports can be supplied when requested before production or shipment.
Need ASTM A193 B8M Class 2 stud bolts?
Send your standard, diameter, length, nut requirement, flange class, material certificate needs and quantity. Our team can confirm B8M stud bolt specification for flange and pressure equipment projects.
Request a Quote
Get engineering support and pricing for this product — our team responds within 24 hours.