S-91084A120 ASTM A108 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 M8x1.25 threaded components, eliminating compatibility issues in mixed-standard assemblies.
• Superior Corrosion Resistance – Black-oxide steel surface treatment provides enhanced durability and protection against rust in demanding industrial environments.
• High Tensile Strength & Hardness – With 78,000 psi tensile strength and Rockwell B85 hardness, it withstands heavy loads and repeated use without stripping or deformation.
• Precision Thread Fit – Class 2B (inch) and Class 6H (metric) thread fits ensure tight, secure connections that minimize vibration loosening and leakage risks.
• Convenient External Hex Drive – 1/2" hex drive with 2-1/2" length offers ample torque application surface for easy installation and removal using standard tools.
• Compliance with Industry Standards – Manufactured to ASTM A108 specifications and RoHS 3 compliant, ensuring material consistency and environmental safety for global supply chains.
• Robust Hexagonal Design – Hex shape provides superior grip and torque transmission, reducing slippage during high-stress operations.

Professional Applications & Engineering Value

This female hex thread adapter solves critical challenges in machinery, automotive, and heavy equipment industries where inch and metric systems intersect. The black-oxide steel construction resists corrosion in humid or outdoor settings, while the Class 2B/6H thread fit maintains sealing integrity under vibration. Engineers value its ability to bridge 5/16"-18 to M8x1.25 connections without custom machining, reducing downtime in assembly lines. The external hex drive design allows quick tool engagement, making it ideal for maintenance tasks requiring frequent adapter use. By meeting ASTM A108 material standards, it delivers consistent performance in high-torque applications like hydraulic systems and structural fastening.

Specification Summary & Compliance

Thread dimensions adhere to Class 2B (inch) and Class 6H (metric) tolerance standards for precise fit. Manufactured under ASTM A108 guidelines for material quality and strength. Fully RoHS 3 (2015/863/EU) compliant with exemption 6(a)-I, ensuring regulatory acceptance for industrial and export use. The adapter maintains dimensional accuracy across 1/2" hex drive and specified thread lengths (5/8" inch, 16 mm metric) for reliable performance in conversion applications.