S-91082A120 ASTM A108, ASTM B633 Inch-to-Metric Female Hex Thread Adapters

Key Features & Benefits at a Glance

• Seamless Inch-to-Metric Conversion – Enables reliable connection between 5/16"-18 and M4 threaded components, eliminating compatibility issues in mixed-standard assemblies.
• Exceptional Tensile Strength – Withstands up to 78,000 psi, providing dependable load-bearing capacity in high-stress industrial applications.
• Corrosion-Resistant Zinc-Plated Steel – Offers enhanced durability and protection against rust, extending service life in harsh environments.
• Precision Thread Fit – Class 2B (inch) and Class 6H (metric) threads ensure accurate, secure mating with minimal risk of cross-threading or loosening.
• Convenient External Hex Drive – 1/2" hex size and 2 1/2" length allow for easy installation and removal using standard wrenches, improving assembly efficiency.
• Certified Material Quality – Manufactured from ASTM A108 compliant steel with Rockwell B85 hardness, guaranteeing consistent mechanical properties and reliability.
• Regulatory Compliance – Meets RoHS 3 standards, ensuring environmental safety and suitability for global industrial supply chains.

Professional Applications & Engineering Value

This female hex thread adapter is engineered to solve critical challenges in machinery, automotive, and equipment manufacturing where inch and metric thread systems must interface seamlessly. The zinc-plated steel construction provides excellent corrosion resistance, reducing maintenance needs in exposed or humid conditions. With a Class 2B/6H thread fit, it ensures precise alignment and vibration resistance, preventing leaks or joint failures in hydraulic, pneumatic, and structural assemblies. The external hex drive and generous hex length facilitate quick tool access, speeding up installations in confined spaces. Ideal for OEMs and MRO operations, this adapter enhances assembly efficiency while maintaining ASTM A108 material integrity across demanding applications.

Specification Summary & Compliance

This adapter features inch thread size 5/16"-18 with Class 2B fit and metric thread M4 with Class 6H fit, ensuring dimensional accuracy per standard tolerances. It complies with ASTM A108 and ASTM B633 specifications for material and plating quality, and is RoHS 3 (2015/863/EU) compliant under exemption 6(a)-I for lead as an alloying element in steel. The external hex drive measures 1/2" across flats with a 2 1/2" length, supporting reliable torque application in industrial use.