S-93985A521 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Precise shoulder positioning with 1/8" diameter and 7/16" length tolerances as tight as ±0.002" for accurate component alignment
• Exceptional mechanical durability from 416 Stainless Steel offering 120,000 psi tensile strength and Rockwell C26 hardness
• Reliable thread engagement with Class 2A UNC coarse threads ensuring consistent fastening in industrial applications
• Easy installation and removal via 5/64" hex socket drive for secure tool grip and reduced assembly time
• Corrosion-resistant performance in demanding environments thanks to 416 Stainless Steel construction
• Environmental regulation compliance with RoHS 3 and REACH standards for safe, sustainable usage
• Smooth head texture preventing damage to mating surfaces while maintaining a professional finish

Professional Applications & Engineering Value

This 4-40 UNC shoulder screw delivers critical precision in machinery where alignment and rotational control are paramount. The 416 Stainless Steel construction resists corrosion while the Class 2A thread fit maintains consistent clamping force in vibrating environments. Its 1/8" shoulder diameter acts as a precise pivot or spacer in assemblies like rotating shafts, bearing mounts, and precision instruments. The coarse thread spacing enables quick assembly in production lines, while the socket head design allows access in confined spaces. Engineers specify this shoulder screw for applications requiring exact shoulder positioning and reliable performance under mechanical stress.

Specification Summary & Compliance

Manufactured to exact Class 2A thread fit standards with UNC coarse threading (4-40 size). Shoulder diameter tolerance: -0.001" to 0", shoulder length tolerance: 0" to 0.002". Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Material certification includes 416 Stainless Steel with verified Rockwell C26 hardness and 120,000 psi tensile strength.