S-91327A281 4-40 ASME B18.3 Shoulder Screws
Shoulder Screws
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Vibration-resistant locking with nylon patch thread locker, maintaining secure fastening from -50° to 250° F to prevent loosening in dynamic environments.
- Superior corrosion resistance from 18-8 stainless steel and passivated finish, ensuring long-term durability in harsh industrial conditions.
- High tensile strength of 70,000 psi and Rockwell B55 hardness for reliable load-bearing capacity in demanding applications.
- Precise Class 3A thread fit for tight tolerances and smooth assembly, reducing installation time and improving joint integrity.
- Easy installation and removal with hex socket drive and 5/64" drive size, allowing efficient tool access in confined spaces.
- Standardized UNC coarse threads and right-hand threading for compatibility with common industrial components and simplified inventory management.
- Compliance with ASME B18.3, RoHS 3, and REACH for guaranteed quality, safety, and environmental responsibility in global supply chains.
Professional Applications & Engineering Value
This 4-40 UNC shoulder screw is engineered to address critical challenges in precision assemblies, such as misalignment and vibration-induced failure. The 18-8 stainless steel construction, combined with a passivated finish, provides excellent resistance to rust and chemicals, making it ideal for machinery, electronics, and automotive systems exposed to moisture or temperature fluctuations. The integrated nylon patch thread locker ensures that the screw remains securely fastened even under continuous stress, reducing maintenance needs and downtime. With a Class 3A thread fit and ASME B18.3 compliance, it delivers consistent performance in high-tolerance applications, from mounting bearings to aligning components, enhancing overall equipment reliability and lifespan.
Specification Summary & Compliance
This shoulder screw features a Class 3A thread fit with UNC coarse threads, ensuring precise dimensional accuracy and easy engagement. It adheres to ASME B18.3 manufacturing standards for uniformity and reliability. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming it is free from hazardous substances and suitable for environmentally conscious industrial use.
