S-91082A125 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 4-40 (inch) and M3.5 (metric) threaded components, eliminating compatibility issues in mixed-standard assemblies.
• Exceptional Corrosion Resistance – Zinc-plated steel construction provides durable protection against rust and environmental wear, extending service life in harsh industrial conditions.
• High Tensile Strength for Demanding Loads – 78,000 psi tensile strength ensures secure, vibration-resistant fastening under high-stress applications without failure.
• Precision Thread Fit for Leak-Free Performance – Class 2B (inch) and Class 6H (metric) thread tolerances guarantee accurate alignment and prevent loosening in dynamic operations.
• Optimized Torque Application – External hex drive with 1/4" hex size allows for easy installation using standard wrenches, reducing assembly time and tooling complexity.
• Certified Material Integrity – ASTM A108 and ASTM B633 compliance ensures consistent mechanical properties and material quality for engineering reliability.
• Environmentally Compliant Manufacturing – RoHS 3 (2015/863/EU) adherence with exemption 6(a)-I supports sustainable procurement and safe use in regulated industries.

Professional Applications & Engineering Value

This female hex thread adapter bridges critical gaps in multi-standard machinery, electronics, and automotive systems where inch and metric threading coexist. Crafted from zinc-plated steel with Rockwell B85 hardness, it resists deformation under repetitive torque cycles, solving common issues of thread stripping and galvanic corrosion. The external hex drive design ensures straightforward access in confined spaces, while the precise Class 2B and 6H thread fits maintain alignment in high-vibration environments like robotics or conveyor systems. By converting 4-40 to M3.5 threads with 78,000 psi tensile strength, it eliminates the need for custom fittings, reducing inventory costs and assembly errors in OEM and MRO operations.

Specification Summary & Compliance

This adapter meets Class 2B (inch) and Class 6H (metric) thread tolerances for dimensional accuracy, with thread lengths of 1/4" (4-40) and 9.5 mm (M3.5). Manufactured in accordance with ASTM A108 and ASTM B633 standards, it guarantees material consistency and performance reliability. The product is RoHS 3 (2015/863/EU) compliant under exemption 6(a)-I for lead as an alloying element in steel, ensuring adherence to environmental and safety regulations in industrial applications.