S-91259A622 5/16"-18 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional strength and durability with alloy steel construction and Rockwell C32 hardness, ensuring reliable performance in demanding industrial environments.
• Precise thread engagement with Class 3A fit and 5/16"-18 UNC coarse threads, providing secure fastening and reduced risk of cross-threading.
• Corrosion-resistant black oxide finish enhances longevity by protecting against rust and wear in harsh operating conditions.
• High load-bearing capacity with 140,000 psi tensile strength and 84,000 psi shear strength, ideal for heavy-duty applications requiring robust fastening.
• Accurate shoulder dimensions featuring a 3/8" diameter and 3/4" length with tight tolerances, enabling precise alignment and smooth rotation in assemblies.
• Easy installation and removal thanks to the hex drive socket head and knurled texture, allowing for efficient tool engagement and reduced slippage.
• Compliance with industry standards including ASME B18.3, RoHS 3, and REACH, ensuring safety, quality, and environmental responsibility.

Professional Applications & Engineering Value

This shoulder screw is engineered to address critical challenges in machinery, automation, and precision equipment, where misalignment and component wear are common issues. The alloy steel material and black oxide finish provide superior resistance to corrosion and mechanical stress, extending service life in high-vibration environments. The 3/8" shoulder diameter and precise tolerances ensure accurate positioning of moving parts, such as in bearings or pulleys, reducing friction and maintenance needs. With UNC coarse threads and Class 3A fit, it offers quick assembly and reliable holding power, making it ideal for heavy-duty fastening in industries like automotive, aerospace, and industrial manufacturing. This screw delivers consistent performance, minimizing downtime and enhancing operational efficiency.

Specification Summary & Compliance

This shoulder screw features a 5/16"-18 UNC thread with Class 3A fit for precise thread engagement, along with a shoulder diameter of 3/8" (tolerance: -0.004" to -0.002") and shoulder length of 3/4" (tolerance: -0.005" to 0.005"). It meets ASME B18.3 specifications for dimensional accuracy and is manufactured in compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, ensuring environmental safety and adherence to global standards.