High-Quality Stainless Steel B8 and B8m Stud Bolts
Originally introduced in 1936, the ASTM A193 specification is widely used in the petroleum and chemical industries. This standard covers both inch and metric series products and includes alloy steel and stainless steel bolting materials suitable for high-temperature or high-pressure applications. The fasteners are commonly used in pressure vessels, valves, flanges, and fittings. While national coarse (UNC) thread pitches are typically available, for traditional applications, threads are specified at 8 threads per inch (tpi) for diameters above one inch.
Common Grades of A193
| B8 |
Class 1 – Stainless steel, AISI 304, solution annealed. |
| B8M |
Class 1 – Stainless steel, AISI 316, solution annealed. |
| B8 |
Class 2 – Stainless steel, AISI 304, solution annealed, strain hardened. |
| B8M |
Class 2 – Stainless steel, AISI 316, solution annealed, strain hardened. |
| Grade |
Size |
Tensile ksi, min |
Yield, ksi, min |
Elong, %, min |
RA %, min |
HBW |
HRC |
| B8 Class 1 |
All |
75 |
30 |
30 |
50 |
223 max |
35 max |
| B8M Class 1 |
All |
75 |
30 |
30 |
50 |
223 max |
96 max |
| B8 Class 2 |
Up to 3/4 |
125 |
100 |
12 |
35 |
321 max |
35 max |
| 7/8 - 1 |
115 |
80 |
15 |
35 |
| 1-1/8 - 1-1/4 |
105 |
65 |
20 |
35 |
| 1-3/8 - 1-1/2 |
100 |
50 |
28 |
45 |
| B8M Class 2 |
Up to 3/4 |
110 |
95 |
15 |
45 |
321 max |
35 max |
| 7/8 - 1 |
100 |
80 |
20 |
45 |
| 1-1/8 - 1-1/4 |
95 |
65 |
25 |
45 |
| 1-3/8 - 1-1/2 |
90 |
50 |
30 |
45 |
| Element |
B8 (AISI 304) |
B8M (AISI 316) |
| Carbon |
0.08% max |
0.08% max |
| Manganese |
2.00% max |
2.00% max |
| Phosphorus, max |
0.045% |
0.045% |
| Sulfur, max |
0.030% |
0.030% |
| Silicon |
1.00% max |
1.00% max |
| Chromium |
18.0 - 20.0% |
16.0 - 18.0% |
| Nickel |
8.0 - 11.0% |
10.0 - 14.0% |
| Molybdenum |
 |
2.00 - 3.00% |
| Bolt Grade |
Nuts |
Washers |
| B8 Class 1 |
A194 Grade 8 |
SS304 |
| B8M Class 1 |
A194 Grade 8M |
SS316 |
| B8 Class 2 |
A194 Grade 8 |
SS304 |
| B8M Class 2 |
A194 Grade 8M |
SS316 |
| Wide Product Range |
We offer a wide range of stainless steel hardware solutions for different applications. |
| Excellent Service |
We provide honest and sincere service to our clients with a strong commitment to quality and reliability. |
| Superior Quality |
Our strict quality control ensures that all products meet the highest standards and enjoy a great reputation in the market. |
| OEM Capabilities |
We can produce custom-made parts based on your drawings or samples. |
| Fast Delivery |
We maintain large stock and offer quick delivery—3 days for stock items, 7–15 days for custom production. |
| Low MOQ |
We support small orders to meet various business needs efficiently. |
| Sample Charge |
Sampling Time |
| Customized as per request |
5–7 days |
| Free for existing molds |
3 days |
| Carton Size: 25*16*25CM |
| Wooden Pallet/Case Size: 110*90*80CM |
| Color-printed boxes and cartons can be customized according to customer preferences. |
Company Profile:Hand Industrial Ltd was established in 2010 and is a professional manufacturer and supplier of stainless steel hardware. Our product range includes stainless steel bolts, threaded studs, machine screws, tapping screws, self-drilling screws, and more in materials such as SS 304, SS 316, SS 316L, SS 410, etc. We can produce to DIN, ANSI, BS, ISO, JIS standards, and OEM services are available. Our products are popular in Europe, Australia, North America, the Middle East, Southeast Asia, and some African countries.
We supply a wide range of super alloy steel hex bolts, hex socket bolts, threaded studs, hex nuts, and plain washers.
We also provide various sizes of SS hex bolts, hex socket bolts, threaded nuts, hex nuts, and plain washers.Swing Head 5-axis CNC Machining Center
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