Home >ASTM A193 B8 CL4 Bolts
Majid Fasteners is a well-established producer and distributor of high quality industrial fasteners in Dubai, UAE, as well as high-performance ASTM A193 B8 Class 4 bolts. Our products are made to accommodate the high requirements of the critical applications with emphasis on high engineering accuracy, superior strengths and high-level corrosion resistance. Our high-quality assurance and supported by modern manufacturing plants provide reliable fastening products to various industries including petrochemical, oil and gas, power generation, marine, and many more. We deliver the best and that is why we are a choice of partners in the region.
The ASTM A193 Grade B8 (Class 4) bolt is manufactured from Cold Formed, Highly Strain Hardened Grade 304 Stainless Steel, which has incredibly high tensile strength and corrosion resistance. In terms of chemistry, Class 4 bolts have a chemical composition consisting of 18% to 20% chromium, 8% to 12% nickel, as well as controlled carbon content for better durability and stability. With regard to mechanical characteristics, Class 4 bolts possess a substantially higher tensile and yield strength than Class 1, Class 2, and Class 3, primarily because of excessive cold working and cold work hardening bringing the tensile strength of Class 4 bolts to approximately 140 ksi. The mechanical performance of Class 4 bolts and their superior resistance to heat, most chemicals, and oxidation qualify them for use in the most demanding industrial and high-pressure applications.
|
Material |
Specification |
Standards |
Size
|
Length |
|
ASTM A193 B8 CL4 Bolt
|
IS
BS
ASTM
|
DIN, ISO, JIS, GB, IS, BS, ASTM |
M 02 to M 160
|
3 mm to 200 mm
|
| Element | B7 | B8 | B8M |
| Carbon | 0.37 – 0.49% | 0.08% max | 0.08% max |
| Manganese | 0.65 – 1.10% | 2.00% max | 2.00% max |
| Phosphorus, max | 0.035% | 0.045% | 0.045% |
| Sulfur, max | 0.040% | 0.030% | 0.030% |
| Silicon | 0.15 – 0.35% | 1.00% max | 1.00% max |
| Chromium | 0.75 – 1.20% | 18.0 – 20.0% | 16.0 – 18.0% |
| Nickel | 8.0 – 11.0% | 10.0 – 14.0% | |
| Molybdenum | 0.15 – 0.25% | 2.00 – 3.00% |
| Grade | Size | Tensile ksi, min | Yield, ksi, min | Elong, %, min | RA % min |
| B7 | Up to 2-1/2 | 125 | 105 | 16 | 50 |
| 2-5/8 – 4 | 115 | 95 | 16 | 50 | |
| 4-1/8 – 7 | 100 | 75 | 18 | 50 | |
| B8 Class 1 | All | 75 | 30 | 30 | 50 |
| B8M Class 1 | All | 75 | 30 | 30 | 50 |
| B8 Class 2 | Up to 3/4 | 125 | 100 | 12 | 35 |
| 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 |
| 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 |
The industries where ASTM A193 B8 Class 4 bolts are applied depict the necessity of extremely high-strength and corrosion-resistant fasteners that can work in the most extreme conditions. These bolts are suitable when used in conditions of great importance in petrochemical industries, oil and gas industries, refineries and high pressurized pipelines. They are applicable in a high-temperature or corrosive environment in pressure vessels, reactors, heat exchangers, flanges, and valves due to their high mechanical property. They are long lasting in marine and offshore structures which come in contact with salt water. They are also applicable in power generation and chemical processing as well as heavy industrial machinery where utmost reliability and safety is vital.
We provide products that come with both mill test certificates and third-party test certificates, ensuring the highest standards of quality and compliance.
