Hex Head Captive Screw

The hex head captive screw features an internal hex (Allen) drive that delivers high torque in a compact head profile, making it ideal for tight-clearance applications inside engines, transmissions, precision machinery, and motorcycle assemblies. This design minimizes tool interference and provides precise clamping force where external wrench access is limited. The product is a preferred choice for precision assemblies that demand reliable, high-torque fastening in restricted spaces.

Manufactured to ISO 4762, SAE J429 Gr.8/10.9/12.9, and GB/T 70.1 standards, the hex head captive screw is available in grades 8.8, 10.9, and 12.9. Materials include 45# carbon steel and 42CrMo alloy, heat-treated for uniform hardness. Grade 12.9 achieves tensile strength ≥1220 MPa and yield strength ≥1080 MPa. The hex socket meets H12 tolerance for secure tool engagement. Surface options such as zinc, nickel, or Dacromet provide corrosion resistance from 240 to 720 hours under harsh conditions.

Thread sizes range from M2–M24, with lengths of 3–150 mm, and are available with cylindrical or countersunk heads. Thread accuracy is 6g, and head height tolerance is ±0.02 mm. Cold-forming and precision milling ensure accurate socket dimensions, while rolled threads provide consistent torque transfer (≤2% variation). We offer customized thread sizes, lengths, head styles, and finishes, including fine-pitch or shoulder variants, to meet specific space-constrained, high-torque requirements.

We operate dedicated milling and heat-treatment lines for the hex head captive screw. Each batch undergoes socket accuracy, torque, and mechanical testing. IATF 16949 certification ensures full traceability. We provide custom assemblies and technical support, offering high-torque performance and precise dimensions for precision assemblies that demand reliability in a compact design.