S-91259A639 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Superior load-bearing capability with 140,000 psi tensile strength and 84,000 psi minimum shear strength for demanding industrial applications
• Precision thread engagement with Class 3A fit ensuring reliable fastening and vibration resistance in machinery assemblies
• Enhanced corrosion resistance through black oxide finish that provides durable protection in harsh operating environments
• Secure installation and removal with 3/16" hex drive and knurled head texture for superior tool grip and torque transmission
• Accurate component alignment with precisely machined shoulder featuring tight diameter and length tolerances
• Consistent performance backed by Rockwell C32 hardness and alloy steel construction for long-term reliability
• Global compliance assurance meeting ASME B18.3 specifications, RoHS 3, and REACH regulations for international projects

Professional Applications & Engineering Value

This high-strength shoulder screw delivers exceptional engineering value in precision machinery and industrial equipment applications. The 5/16"-18 UNC coarse thread with Class 3A fit ensures rapid assembly while maintaining vibration resistance in rotating components and linkages. The alloy steel construction with black oxide finish provides superior corrosion protection for extended service life in manufacturing environments. The precisely machined shoulder diameter and length tolerances enable accurate component positioning in assemblies, eliminating misalignment issues. The 3/16" hex drive with knurled head offers secure tool engagement for high-torque applications, making these socket head shoulder screws ideal for robotics, automation systems, and heavy machinery where reliability is critical.

Specification Summary & Compliance

This shoulder screw features precision 5/16"-18 UNC coarse threads with Class 3A thread fit for superior engagement. Critical dimensions include shoulder diameter of 3/8" with tolerance of -0.004" to -0.002" and shoulder length of 3 3/4" with tolerance of -0.005" to 0.005". Manufactured to ASME B18.3 specifications using ASTM A574 alloy steel, with full compliance to RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations for global industrial applications.