S-91829A521 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and passivated finish for extended service life in harsh environments
• Precise alignment and positioning thanks to the 1/8" shoulder diameter with tight tolerance (-0.001" to 0") for reliable mechanical assembly
• High mechanical strength offering 70,000 psi tensile strength and Rockwell B55 hardness for demanding industrial applications
• Easy installation and removal with socket/slotted drive combination and right-hand UNC coarse threads for efficient assembly
• Consistent thread performance through Class 2A thread fit ensuring smooth engagement and vibration resistance
• Regulatory compliance assurance meeting RoHS 3 and REACH standards for safe use across global markets
• Versatile shoulder design featuring 7/16" shoulder length with precise tolerance (0" to 0.002") for accurate component spacing

Professional Applications & Engineering Value

Engineered for precision mechanical systems, this 4-40 UNC shoulder screw solves critical alignment challenges in industrial equipment. The 18-8 stainless steel construction with passivated finish provides exceptional corrosion resistance, making it ideal for manufacturing environments exposed to moisture or chemicals. The 1/8" shoulder diameter with precise tolerance maintains component positioning in assemblies where radial clearance is critical, while the Class 2A thread fit ensures reliable fastening in vibrating applications. These shoulder screws deliver consistent performance in precision instruments, automation equipment, and mechanical linkages where dimensional stability and corrosion resistance are paramount for long-term reliability.

Specification Summary & Compliance

This precision shoulder screw features 4-40 UNC coarse threads with Class 2A thread fit for standard industrial applications. The shoulder maintains tight dimensional control with diameter tolerance of -0.001" to 0" and length tolerance of 0" to 0.002". Manufactured from 18-8 stainless steel with Rockwell B55 hardness and 70,000 psi tensile strength, the component is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations for environmental safety and industrial use.