ASTM A193 Grade B8MLN is a standard material specification for corrosion resistant 316LN fasteners such as bolts, screws, studs, threaded rods and other externally threaded parts, for use in high tensile, high temperature and special purpose applications such as pressure piping & pressure vessels bolting. Grade B8MLN is a carbide solution treated 316LN stainless steel material having classified under tensile class 1 & 1D with minimum tensile requirement of 75 ksi, yield 30 ksi and maximum hardness limit of 223 HBW or 96 HRB. This specification covers requirements for chemical composition, mechanical properties, hardness, heat-treatment and recommended nuts-washers for Grade B8MLN Fasteners.
| Element | Austenitic Stainless Steel |
|---|---|
| UNS S31653 / AISI 316LN / 1.4429 | |
| CompositionA, % | |
| Carbon | 0.03 max |
| Manganese | 2.00 |
| Phosphorus | 0.045 max |
| Sulfur | 0.030 max |
| Silicon | 1.00 max |
| Chromium | 16.00 - 18.00 |
| Nickel | 10.00 - 13.00 |
| Molybdenum | 2.00 - 3.00 |
| Nitrogen | 0.10 - 0.16 |
A: The intentional addition of Bi, Se, Te, and Pb is not permitted.
| Tensile Class | Diameter, Inch | Tensile Strength, min, ksi |
Yield Strength, min, 0.2% offset, ksi |
Elongation in 4D, min, % |
Reduction of Area, min, % |
Hardness, max |
|
|---|---|---|---|---|---|---|---|
| Class 1 & 1D | All Sizes | 75 | 30 | 30 | 50 | 192 HBW or 90 HRB | |
Heat Treatment: Carbide Solution Treated in finished condition.
| Nut Specification | Washer Specification |
|---|---|
| ASTM A194 Grade 8MLN | ASTM A240 UNS S31653 |
| Commonly Produced B8MLN Fasteners | ||||
|---|---|---|---|---|
| Hex Bolts | Heavy Hex Bolts | Stud Bolts | Threaded Rods | Anchor Bolts |
| Eye Bolts | Socket Head Cap Screws | Countersunk Screws | U Bolts | Square Head Bolts |