S-90298A580 1/4"-20 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Precision shoulder control with ±0.001" diameter and ±0.005" length tolerances ensures perfect alignment and reduced assembly vibration in high-accuracy applications
• Superior corrosion resistance from 18-8 stainless steel construction and passivated finish extends service life in harsh industrial environments
• High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness withstands heavy mechanical loads and repeated use
• Secure fastening engagement through Class 3A thread fit provides tighter tolerances than standard commercial grades for vibration-resistant assemblies
• Easy installation and removal with 5/32" hex socket drive and knurled head design allows positive tool grip even with lubricated gloves
• Industry-standard compatibility with UNC coarse threading ensures interchangeability with existing 1/4"-20 components and tooling
• Regulatory compliance with ASME B18.3, RoHS 3, and REACH standards guarantees material safety and quality consistency for global supply chains

Professional Applications & Engineering Value

This socket head shoulder screw delivers critical precision for applications requiring exact rotational clearance and alignment. The 18-8 stainless steel construction combined with passivated finish provides exceptional resistance to corrosion and chemical exposure in manufacturing environments, food processing equipment, and outdoor machinery. The 5/8" shoulder length with tight diametrical tolerances acts as precise pivot points, bearing surfaces, and alignment guides in assemblies where component spacing must be maintained without binding. The UNC coarse threading and Class 3A thread fit ensure secure fastening in high-vibration applications while the knurled head texture and hex socket drive prevent tool slippage during installation in confined spaces. These shoulder screws solve alignment challenges in robotics, precision machinery, jigs, and fixtures where dimensional accuracy directly impacts operational reliability.

Specification Summary & Compliance

Manufactured to exacting standards with Class 3A thread fit for superior engagement and UNC thread specifications ensuring broad compatibility. Shoulder dimensions maintain precise ±0.001" diameter tolerance and ±0.005" length tolerance for consistent performance. Full compliance with ASME B18.3 manufacturing specifications, RoHS 3 (2015/863/EU) hazardous substance restrictions, and REACH (EC 1907/2006) chemical regulations for international market acceptance.