S-8077A673 1/4"-28 ASME B18.3 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional corrosion resistance in harsh environments due to 316 stainless steel construction, ideal for marine, chemical, and outdoor applications.
• Superior mechanical strength with 70,000 psi tensile and 35,000 psi shear strength, ensuring reliable performance under high-stress conditions.
• Precise alignment and smooth rotation enabled by the standard shoulder fit and fine UNF thread with Class 3A tolerance for minimal backlash.
• Secure, non-slip installation provided by the knurled socket head and hex drive, allowing for high torque application without stripping.
• Enhanced durability and wear resistance from the black oxide finish, which also adds a sleek, professional appearance.
• Broad regulatory compliance including ASME B18.3, RoHS 3, and REACH, ensuring safety and environmental standards are met for global industrial use.
• Optimized for precision assemblies with controlled shoulder diameter and length tolerances, reducing the need for additional components in machinery and fixtures.

Professional Applications & Engineering Value

This 316 stainless steel shoulder screw is engineered to address critical challenges in precision industrial applications, such as aligning rotating parts in machinery, securing bearings, and acting as axles or pivots. The Class 3A UNF fine thread ensures tight, vibration-resistant connections, reducing maintenance needs in automated systems. Its black oxide finish not only enhances corrosion resistance but also minimizes galling, a common issue in stainless steel fasteners. With a knurled socket head and hex drive, it offers easy installation in confined spaces, making it ideal for high-torque assembly in automotive, aerospace, and electronic equipment where reliability and long service life are paramount.

Specification Summary & Compliance

This shoulder screw adheres to Class 3A thread fit per UNF standards, ensuring high precision and interchangeability. Dimensions include a 1/4"-28 thread with fine spacing, 3/8" shoulder diameter, and 1 3/4" shoulder length, manufactured to tight tolerances (e.g., shoulder diameter: -0.004" to -0.002"). It meets ASME B18.3 specifications for dimensional consistency and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free of hazardous substances for safe use in various industries.