ASTM A193 Grade B8CLN Specification
ASTM A193 Grade B8CLN Specification for high tensile bolts, screws, stud bolts, anchor bolts, threaded rods and other externally threaded fasteners, made from 347LN stainless steel.
ASTM A193 Grade B8CLN is a standard material specification for nitrogen enhanced corrosion resistant grade 347LN stainless steel fasteners, for use in high tensile, high temperature and special purpose applications such as pressure piping & pressure vessels bolting. Grade B8CLN is a carbide solution treated 347LN stainless steel further divided into class 1 and class 1D, having similar requirements. ASTM A193 specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8CLN Fasteners.
Tensile Class
| Property | Description |
|---|---|
| Class 1 | Carbide Solution Treated |
| Class 1D | Carbide Solution Treated |
Chemical Composition
| Element | Austenitic Stainless Steel |
|---|---|
| AISI 347LN / UNS S34751 | |
| CompositionA, % | |
| Carbon | 0.005 - 0.020 |
| Manganese | 2.00 |
| Phosphorus | 0.045 max |
| Sulfur | 0.030 max |
| Silicon | 1.00 max |
| Chromium | 17.00 - 19.00 |
| Nickel | 9.00 - 12.00 |
| Columbium | 15 x Carbon Content min |
| Nitrogen | 0.06 - 0.10 |
AThe intentional addition of Bi, Se, Te, and Pb is not permitted.
Mechanical Properties
| Tensile Class | Diameter, Inch | Tensile Strength, min, ksi |
Yield Strength, min, 0.2% offset, ksi |
Elongation in 4D, min, % |
Reduction of Area, min, % |
Hardness, maxA |
|---|---|---|---|---|---|---|
| Class 1 | All Sizes | 75 | 30 | 30 | 50 | 223 HBW or 96 HRB |
| Class 1D | All Sizes | 75 | 30 | 30 | 50 | 223 HBW or 96 HRB |
Heat Treatment: Carbide Solution Treated
A: For sizes 3⁄4 in. in diameter and smaller, a maximum hardness of 241 HBW (100 HRB) is permitted.
