S-91259A425 10-24 ASME B18.3, ASTM A108 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Durability: Alloy steel construction with black oxide finish provides superior corrosion resistance and long-lasting performance in demanding environments.
• High Tensile Strength: Rated at 140,000 psi tensile strength and Rockwell C32 hardness to withstand heavy loads and prevent mechanical failure.
• Precision Fit & Alignment: Class 3A thread fit and controlled shoulder diameter tolerance ensure accurate assembly and reliable component positioning.
• Secure, Non-Slip Fastening: Knurled head texture combined with hex socket drive allows for high-torque installation without slipping or stripping.
• Broad Industrial Compliance: Meets ASME B18.3 specifications and is RoHS 3 & REACH compliant for safe, regulated use across various sectors.
• Optimized for Coarse Thread Applications: 10-24 UNC coarse thread design enables quick assembly and better performance in materials requiring deeper engagement.
• Consistent Shoulder Dimensions: 3/8" shoulder length with tight length tolerance provides a stable bearing surface for rotating parts and precise spacing.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical alignment and durability challenges in mechanical assemblies. The black oxide finish enhances corrosion resistance, making it suitable for environments exposed to moisture or chemicals. Its 10-24 UNC coarse thread and Class 3A fit ensure secure fastening with minimal risk of cross-threading, while the precisely machined shoulder acts as a reliable axle or pivot point in machinery, conveyor systems, and automation equipment. The knurled socket head allows for high-torque application, preventing tool slippage during installation. Ideal for use in robotics, automotive jigs, and precision manufacturing fixtures, this screw provides consistent performance where exact part positioning and high tensile strength are paramount.

Specification Summary & Compliance

This shoulder screw adheres to ASME B18.3 standards, with a Class 3A thread fit for superior precision. Key dimensional tolerances include a shoulder diameter of 1/4" (tolerance: -0.004" to -0.002") and shoulder length of 3/8" (tolerance: -0.005" to 0.005"). The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and regulatory acceptance in industrial markets.