High-strength M21x20mm hex head cap screw crafted from premium Aluminum 6061. Offers exceptional corrosion resistance and a lightweight profile, ideal for critical industrial assemblies.
| Standard | ASTM A106 |
| Material | Aluminum 6061 |
| Finish | Black Oxide |
| Grade | N/A |
| Size | M21 |
| Length | 20mm |
| Head Width | 24mm |
Designed for demanding industrial environments, this M21x21mm hex head cap screw is manufactured from Aluminum 6061, a robust alloy known for its excellent strength-to-weight ratio and superior corrosion resistance, particularly in marine and chemical atmospheres. The nominal thread diameter is 21mm, with a precise grip length of 20mm. The head features a standard 24mm hex width, compatible with common industrial tooling for secure installation. This fastener is engineered for applications requiring reliable joining without the significant weight penalty of steel, making it suitable for aerospace, automotive, and structural components where weight optimization is paramount.
This component strictly adheres to the tolerances, material specifications, and quality benchmarks set by the world's leading industrial manufacturers.
1. Ensure mating threads are clean and free from debris. 2. Hand-thread the cap screw to confirm proper engagement and alignment. 3. Tighten to the manufacturer-specified torque using a calibrated torque wrench, avoiding over-tightening.
| Standard System | Designation |
|---|---|
| ISO Equivalent | ISO 898-1 / ISO 4014 |
| DIN Equivalent | DIN 931 / DIN 933 |
| Primary Standard | ASTM A106 |
| Tensile Strength | Standard Commercial Spec |
| Yield Strength | Standard Commercial Spec |
| Hardness | Varies by specific batch |
| Bolt Size | Dry Torque (ft-lbs) | Lubricated Torque (ft-lbs) |
|---|---|---|
| M21 | Check Calculator | Reduce by 25% |
| Size / Type | Est. Weight (lbs/100) | Shipping Weight (kg) |
|---|---|---|
| M21 | Varies by dimension | Contact Sales |
| Environment | Rating |
|---|---|
| Indoor / Dry | Excellent |
| Outdoor / Exposed | Moderate |
| Marine / Saltwater | Not Recommended |
| Chemical / Acidic | Not Recommended |
| ❌ Mistake | ✅ Correct Approach |
|---|---|
| Over-tightening the aluminum screw, potentially stripping the threads or deforming the mating component. | Always use a calibrated torque wrench and adhere to recommended torque values for Aluminum 6061 fasteners. |
| Using excessive force with impact tools, which can damage the fastener or surrounding materials. | Hand-tighten initially, then use a torque wrench for final tightening. Avoid impact drivers with aluminum fasteners. |
A: This Hex Head Cap Screw, Aluminum 6061 is manufactured from Aluminum 6061.
A: Aerospace structural components, Automotive chassis and body assemblies, Marine equipment and fixtures.
Conversion factor: 1 ft-lb ≈ 1.356 Nm
| Status | Mating Component | Standard | Torque Spec | Engineering Notes |
|---|---|---|---|---|
| No verified compatibility data found for this component. | ||||