A193 B8M SS316 STUD BOLTS
ASTM A193 B8M SS316 Stud Bolts are high performance stainless steel bolting components manufactured from 316 stainless steel according to ASTM A193 Grade B8M requirements. Compared with B8 SS304 stud bolts, B8M stud bolts contain molybdenum elements that provide improved resistance to pitting and corrosion, making them suitable for more demanding environments.
Designed for applications requiring enhanced corrosion protection and long service life, ASTM A193 B8M stud bolts are commonly used in chemical processing equipment, marine environments, offshore facilities, oil and gas systems and other industrial applications exposed to moisture, chlorides or corrosive media. These stud bolts are typically used with ASTM A194 Grade 8M stainless steel nuts for reliable flange connections.
Specification of A193 B8M stud bolts:
A193 B8M stud bolts, made from stainless steel grade 316, find applications in various industries due to their corrosion resistance and mechanical properties. Here are some common applications:
| Product name | ASTM A193 B8M Stud Bolts |
|---|---|
| Diameter | 1/4″ – 4″ |
| Dimension Standard | ASME B18.31.2 |
| Thread | UNC/UNF/8UN |
| Material | Stainless steel, AISI 316 |
| Compatible nuts/washers | A194 GR.8M heavy hex nuts |
| Manufacturing Process | wire drawing, thread rolling, heat treatment, surface treatment |
| Surface treatment | Black Oxide Coating/Zinc Plating (Electroplating)/Hot-Dip Galvanizing/Mechanical Galvanizing/Dacromet Coating/Painting or Powder Coating |
| Application Industry | Piping Systems/Pressure Vessels/Pressure Vessels/Oil and Gas Industry/Power Generation/Chemical Processing |
A193 B8M stud bolts are specifically chosen for their corrosion resistance and mechanical properties in challenging conditions. Always ensure that the selected fasteners meet the requirements of your specific application to ensure safety and reliability.
Chemical Composition:
| Elements | Range | Allowed Variation, % |
|---|---|---|
| Carbon, max | 0.08 % | + 0.01 |
| Manganese, max | 2.00 % | + 0.04 |
| Phosphorus, max | 0.045 % | + 0.010 |
| Sulfur, max | 0.030 % | + 0.005 |
| Silicon, max | 1.00 % | + 0.05 |
| Chromium | 16.00 – 18.00 % | +/- 0.20 |
| Nickel | 10.00 – 14.00 % | +/- 0.15 |
| Molybdenum | 2.00 – 3.00 % | +/- 0.10 |
Mechanical and physical properties:
| Mechanical Requirements, Inch Products | |||||||
|---|---|---|---|---|---|---|---|
| Class | Diameter | Tensile Strength, min, ksi | Yield Strength, min, ksi | Elongation in 4D min, % | Reduction of Area, min, % | Hardness, max | |
| B8M class 1 | All Diameters | 75 | 30 | 30 | 50 | 223 HBW | 96 HRB |
| B8M class 2 | 3/4 and under | 110 | 95 | 15 | 45 | 321 HBW | 35 HRC |
| Over ¾ to 1, incl. | 100 | 80 | 20 | 45 | |||
| Over 1 to 1-1/4, incl. | 95 | 65 | 25 | 45 | |||
| Over 1-1/4 to 1-1/2, incl. | 90 | 50 | 30 | 45 | |||
Quality control of A193 B8M Stud bolts:
| Inspect Item | Detail |
|---|---|
| Dimensional Inspection | Critical dimensions such as bolt diameter, head width, head height, bolt length and thread length are checked using calibrated measuring equipment. Inspection is carried out according to the applicable dimensional standard or customer drawings to ensure consistent fit and interchangeability. |
| Thread Inspection | External threads are inspected using calibrated GO and NO-GO thread gauges to verify thread profile, pitch and dimensional conformity. Additional measurements can be performed when tighter thread tolerances or specific customer requirements apply. |
| Mechanical Testing | Mechanical properties are verified according to the specified material and strength grade. Depending on the applicable standard, testing may include tensile strength, yield strength, hardness and other required mechanical tests, with test results documented in the relevant inspection or material reports. |
| Surface & Coating Inspection | Bolt surfaces are inspected for appearance, defects, coating uniformity and other specified requirements. For coated fasteners, coating thickness and adhesion or other applicable coating characteristics can be checked according to the specified surface treatment standard. |
| Final Inspection & Testing | Before shipment, finished hex bolts undergo final inspection to confirm dimensions, thread quality, mechanical requirements, surface condition, marking and packaging. Inspection records and test reports can be provided according to the order specification and customer requirements. |