This M21 x 125mm brass hex head cap screw offers superior corrosion resistance and excellent conductivity. Its robust design ensures reliable fastening in demanding environments, making it a preferred choice for specialized industrial applications.
| Standard | ISO 9001 |
| Material | Brass |
| Finish | Plain |
| Grade | N/A |
| Size | M21 |
| Length | 125mm |
| Head Width | 31mm |
A high-performance industrial component, this M21 x 125mm brass hex head cap screw features a nominal diameter of M21, a substantial 125mm length for deep component engagement, and a 31mm hex head width for robust torque application. Constructed from high-grade brass (e.g., UNS C36000/C26000), it exhibits exceptional resistance to corrosion, particularly in marine and humid atmospheres, and possesses excellent electrical conductivity. The inherent malleability of brass also allows for a degree of deformation under load, contributing to a secure, vibration-resistant joint. Its imperial equivalent thread pitch is typically 2.5mm. This specification ensures compatibility with a wide range of metric threaded holes.
This component strictly adheres to the tolerances, material specifications, and quality benchmarks set by the world's leading industrial manufacturers.
1. Select the appropriate tool, such as a wrench or socket, that fits the 31mm hex head snugly. 2. Ensure the mating threaded hole is clean and free of debris. 3. Insert the cap screw and thread it by hand for the initial engagement to prevent cross-threading. 4. Tighten the cap screw using the selected tool to the recommended torque specification for M21 brass fasteners, taking care not to overtighten and strip the threads or damage the brass material.
| Standard System | Designation |
|---|---|
| ISO Equivalent | ISO 898-1 / ISO 4014 |
| DIN Equivalent | DIN 931 / DIN 933 |
| Primary Standard | ISO 9001 |
| 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 |
|---|---|
| Using excessive force leading to stripping of brass threads. | Always refer to recommended torque charts for brass fasteners of this size and use a torque wrench for precise tightening. |
| Using incorrect tool size on the hex head, causing damage and difficulty in removal. | Ensure the wrench or socket used is precisely the correct size (31mm) for the hex head to ensure proper grip and prevent deformation. |
| Not verifying thread compatibility with the mating component. | Confirm that the M21 metric thread of the cap screw matches the thread specification of the component being fastened. |
A: This Hex Head Cap Screw, Brass is manufactured from Brass.
A: Electrical connections and grounding hardware, Marine hardware and fittings, Corrosive environment assemblies.
Conversion factor: 1 ft-lb ≈ 1.356 Nm
| Status | Mating Component | Standard | Torque Spec | Engineering Notes |
|---|---|---|---|---|
| No verified compatibility data found for this component. | ||||