S-91259A436 3/8"-16 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Enhanced Durability & Corrosion Resistance: Black oxide finish provides reliable protection against rust and wear in demanding industrial environments.
• Superior Load-Bearing Capacity: High-strength alloy steel construction delivers 140,000 psi tensile strength and 84,000 psi shear strength for heavy-duty applications.
• Precision Thread Engagement: Class 3A thread fit ensures tight, secure fastening with minimal risk of loosening under vibration or stress.
• Secure Grip & Easy Installation: Knurled head and 1/4" hex drive allow for firm tool engagement and straightforward installation without slippage.
• Accurate Alignment & Bearing Surface: Standard shoulder fit with controlled diameter and length tolerances provides consistent shaft alignment and rotational support.
• Industry Compliance & Reliability: Meets ASME B18.3 specifications and is RoHS 3 and REACH compliant for safe, regulated use in global markets.
• Optimized for High-Stress Applications: Rockwell C32 hardness and coarse UNC threads offer excellent resistance to stripping and deformation.

Professional Applications & Engineering Value

Engineered for precision and endurance, this 3/8"-16 UNC shoulder screw is ideal for applications requiring exact alignment and robust rotational support, such as in machinery assemblies, pivoting mechanisms, and bearing mounts. The alloy steel core, combined with a black oxide finish, resists corrosion and maintains integrity under high tensile and shear loads. Its socket head with knurled texture and hex drive ensure secure tool engagement, reducing installation time and preventing damage in tight spaces. With a Class 3A thread fit and controlled shoulder dimensions, it minimizes play and misalignment, solving common issues like component wobble and premature wear in industrial equipment.

Specification Summary & Compliance

This shoulder screw features a 3/8"-16 UNC coarse thread with Class 3A fit for precise engagement, and shoulder diameter and length tolerances of -0.004" to -0.002" and -0.005" to 0.005", respectively. Manufactured to ASME B18.3 standards using ASTM A574 material, it ensures consistent performance. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, supporting safe and sustainable industrial use.