Alloy Steel Flat Head Socket Cap Screw Bolt-DIN 7991 Allen Head Hex Drive Machine Screw-Countersunk Bolt

描述

1.Premium Performance – Precision-machined from quenched-and-tempered alloy steel (10.9 or 12.9 grade), these flat head socket cap screws deliver exceptional tensile strength (≈ 150-180 ksi / 1000-1240 MPa) and core hardness (HRC 35-44). The 82° or 90° countersunk head design allows for a completely flush surface when properly installed, eliminating protrusions while maintaining maximum clamping force. Their black oxide or phosphate coating provides basic corrosion protection and reduces light reflection in optical-sensitive environments.

2.Extensive Application Range – Ideal for precision assemblies requiring a smooth, flush surface including aircraft components, automotive trim, furniture manufacturing, industrial machinery guards, jig and fixture design, electronic enclosures, and architectural hardware. The countersunk profile makes these fasteners perfect for high-shear applications and locations where protruding heads would interfere with movement or aesthetics, while still delivering the strength of socket cap screws.

3.Installation Efficiency – The deep internal hex socket accepts standard Allen wrenches or power bits, providing excellent torque transfer without driver slippage even in confined spaces. Precision-machined countersink angles match standard hole preparations exactly, ensuring proper seating and load distribution. Rolled threads with chamfered starting points prevent cross-threading and ensure smooth engagement, while the close dimensional tolerances guarantee consistent fit and flush mounting across production runs.

4.Verified Quality – Manufactured in ISO 9001-certified facilities to strict dimensional standards (DIN 7991/ISO 10642/ASME B18.3) and mechanical property requirements (ISO 898-1). Each production lot undergoes comprehensive testing including surface hardness measurement, core hardness verification, tensile strength testing, and thread dimension validation. Available with EN 10204 3.1 material certificates for critical applications and marked with grade identification and manufacturer codes for full traceability throughout the supply chain.