This M21x30mm brass hex head cap screw offers superior corrosion resistance and non-magnetic properties. Its robust hexagonal head ensures secure tightening for critical fastening applications where material integrity is paramount.
| Standard | ASME B18 |
| Material | Brass |
| Finish | Passivated |
| Grade | N/A |
| Size | M21 |
| Length | 30mm |
| Head Width | 20mm |
Specified by design engineers worldwide, this M21x30mm hex head cap screw is manufactured from high-grade brass, offering excellent corrosion resistance, particularly in marine and humid environments. The material's inherent non-magnetic properties make it suitable for sensitive electrical and electronic assemblies. With a nominal size of M21, a length of 30mm, and a head width of 20mm, it provides robust fastening capability. The ductility of brass also allows for some conformity under load, reducing the risk of stress concentration in critical joints.
This component strictly adheres to the tolerances, material specifications, and quality benchmarks set by the world's leading industrial manufacturers.
1. Ensure the mating threads are clean and free of debris. 2. Hand-thread the screw initially to verify alignment and prevent cross-threading. 3. Tighten using an appropriate wrench or socket, applying torque incrementally to the specified limit for the application.
| Standard System | Designation |
|---|---|
| ISO Equivalent | ISO 898-1 / ISO 4014 |
| DIN Equivalent | DIN 931 / DIN 933 |
| Primary Standard | ASME B18 |
| Tensile Strength | Standard Commercial Spec |
| Yield Strength | Standard Commercial Spec |
| Hardness | Varies by specific batch |
| Copper (Cu) | 60.0 - 63.0% |
| Zinc (Zn) | Balance |
| Lead (Pb) | 2.5 - 3.7% |
| 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 brass screw, which can lead to thread stripping or deformation. | Use a torque wrench and adhere to the recommended torque specifications for brass fasteners in your specific application. |
| Using the wrong size wrench, potentially damaging the hex head and hindering proper tightening. | Ensure the wrench or socket perfectly matches the 20mm head width of the cap screw. |
A: This Hex Head Cap Screw, Brass is manufactured from Brass.
A: Marine hardware and fittings, Electrical connectors and enclosures, Decorative architectural elements, Food processing equipment.
Conversion factor: 1 ft-lb ≈ 1.356 Nm
| Status | Mating Component | Standard | Torque Spec | Engineering Notes |
|---|---|---|---|---|
| No verified compatibility data found for this component. | ||||