Alloy Steel Fasteners
Chromium-molybdenum and related alloy steels, quenched and tempered for high strength and for elevated or low temperature pressure service.
Alloy Steel Fasteners
Chromium-molybdenum and related alloy steels, quenched and tempered for high strength and for elevated or low temperature pressure service.
Common standards: ASTM A193 B7/B7M/B16, A194 2H/4, A320 L7, A354 BD, A574, ISO 898-1 10.9/12.9
Common Grades
| Grade | Description |
|---|---|
| B7 | AISI 4140/4142 Cr-Mo for high-temperature and high-pressure service |
| B16 | Cr-Mo-V for elevated temperature service |
| L7 | Impact tested for low-temperature service |
| 4340 | Ni-Cr-Mo high strength |
| A354 BD | High strength structural bolting |
General industry information. Grades listed are not a statement of current stock or manufacture; availability is confirmed at enquiry.
Chemical Composition (% typical specification limits)
| Grade | C | Mn | Cr | Mo | Other |
|---|---|---|---|---|---|
| 4140 | 0.38–0.43 | 0.75–1.00 | 0.80–1.10 | 0.15–0.25 | Si 0.15–0.35 |
| 4340 | 0.38–0.43 | 0.60–0.80 | 0.70–0.90 | 0.20–0.30 | Ni 1.65–2.00 |
| B16 | 0.36–0.47 | 0.45–0.70 | 0.80–1.15 | 0.50–0.65 | V 0.25–0.35 |
Limits vary slightly by product standard. Actual heat analysis is reported on the Material Test Certificate.
Mechanical Properties
| Grade / class | Tensile (MPa) | Yield (MPa) | Hardness |
|---|---|---|---|
| ASTM A193 B7 (≤2½ in) | 860 min | 725 min | 35 HRC max |
| ASTM A193 B7M | 690 min | 550 min | 99 HRB max |
| ASTM A193 B16 (≤2½ in) | 860 min | 725 min | 321 HBW max |
| ASTM A320 L7 | 860 min | 725 min | Impact tested |
| ISO 898-1 Class 12.9 | 1220 min | 1100 min | 39–44 HRC |
Minimum values per cited standards; they vary by diameter, condition and heat treatment.
Available Fastener Types
Available as bolts, nuts, screws, washers, studs and special fasteners to drawing, subject to size and standard. Browse all products.
Applications and Industries
Finishing, Quality and Packaging
Finishes such as passivation, plating, galvanizing or customer-specified treatments are selected to suit the material and service. Inspection may include dimensional, visual, mechanical and chemical checks, PMI where applicable, and Material Test Certificates (EN 10204 3.1 where requested). Goods are packed for export. See Quality.