This M21 x 79mm Hex Head Cap Screw, crafted from high-performance Polycarbonate, offers exceptional strength, corrosion resistance, and electrical insulation. Engineered for demanding applications requiring a robust and non-metallic fastening solution.
| Standard | ASTM A106 |
| Material | Polycarbonate |
| Finish | Black Oxide |
| Grade | N/A |
| Size | M21 |
| Length | 79mm |
| Head Width | 25mm |
Precision-manufactured to tight tolerances, this M21 x 79mm Polycarbonate Hex Head Cap Screw features a 25mm head width. Polycarbonate provides excellent impact strength, chemical resistance to many acids and alkalis, and is inherently non-conductive, making it suitable for environments where electrical conductivity is a concern or can cause interference. Its UV stability ensures longevity in outdoor applications. The metric M21 thread form guarantees secure engagement with corresponding nuts and tapped holes, ideal for structural assembly in chemical processing, medical equipment, and marine environments where traditional metal fasteners would degrade or pose a risk.
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-tighten the M21 x 79mm Polycarbonate Hex Head Cap Screw to engage the threads. 3. Using an appropriate wrench or socket, tighten the screw to the required torque, avoiding over-tightening which can strip the polycarbonate threads.
| 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 screw, leading to stripped threads or cracking of the polycarbonate head. | Utilize a torque wrench and adhere to manufacturer-recommended torque values for polycarbonate fasteners. Hand-tighten first, then apply controlled torque. |
| Using inappropriate tools that can damage the hex head or the screw material. | Employ tools specifically designed for hex head fasteners, ensuring a snug fit to prevent slippage and material damage. Avoid excessive force. |
A: This Hex Head Cap Screw, Polycarbonate is manufactured from Polycarbonate.
A: Chemical processing equipment, Medical device assemblies, Marine and offshore applications.
Conversion factor: 1 ft-lb ≈ 1.356 Nm
| Status | Mating Component | Standard | Torque Spec | Engineering Notes |
|---|---|---|---|---|
| No verified compatibility data found for this component. | ||||