S-92981A912 M4 ASTM A108 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Strength & Durability: Made from high-grade alloy steel with a tensile strength of 140,000 psi and Rockwell C32 hardness, ensuring reliable performance in demanding applications.
• Precision Shoulder for Accurate Alignment: Features a 40mm shoulder length with tight tolerances (±0.25mm) to maintain precise component positioning and reduce assembly errors.
• Enhanced Corrosion Resistance: Black oxide finish provides superior protection against rust and wear, extending the screw's service life in harsh environments.
• Secure & Easy Installation: Hex socket drive (2.5mm) with a knurled head offers improved grip and torque application, minimizing slippage during fastening.
• Consistent Thread Performance: Right-hand metric thread (M4 x 0.7mm coarse pitch) with Class 5g6g fit ensures smooth engagement and reliable holding power.
• Broad Industry Compliance: Meets ASTM A108 specifications and is RoHS 3/REACH compliant, supporting use in regulated and eco-conscious industries.
• Versatile Industrial Application: Ideal for machinery, automotive, and precision equipment where high tensile strength and exact shoulder dimensions are critical.

Professional Applications & Engineering Value

This M4 shoulder screw is engineered to address common industrial challenges such as misalignment and component wear. The alloy steel construction, combined with a black oxide finish, delivers excellent resistance to corrosion and mechanical stress, making it suitable for heavy-duty applications in automotive assemblies, industrial machinery, and precision instruments. The 40mm shoulder length with minimal tolerance ensures accurate pivoting and spacing, reducing the need for additional bushings or washers. Its hex drive socket head and knurled texture facilitate quick, secure installation with standard tools, enhancing assembly efficiency. By integrating metric coarse threads and high tensile strength, this fastener provides reliable performance in dynamic environments, minimizing downtime and maintenance costs.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including a shoulder length tolerance of 0 to 0.25 mm and a shoulder diameter tolerance of -0.072 to -0.01 mm. The thread fit conforms to Class 5g6g per metric standards, ensuring compatibility and performance. It is manufactured in compliance with ASTM A108 and meets regulatory requirements such as RoHS 3 (2015/863/EU) and REACH (EC 1907/2006), confirming its suitability for global industrial use without hazardous substances.