S-94128A143 4-40 Shoulder Screws

Key Features & Benefits at a Glance

• Precise shoulder fit ensures accurate component alignment and reduces assembly vibration in mechanical applications
• Class 3A thread fit provides superior thread engagement and consistent clamping force for critical connections
• Rockwell C32 hardness delivers excellent wear resistance and maintains dimensional stability under repeated use
• Alloy steel construction offers high strength-to-weight ratio and reliable performance in demanding industrial environments
• Slotted drive design enables easy installation and removal with standard tools while maintaining headless profile
• RoHS 3 & REACH compliance ensures environmental responsibility and meets international regulatory standards
• Coarse UNC threading provides faster assembly and reduced cross-threading risk in production environments

Professional Applications & Engineering Value

This 4-40 UNC shoulder screw with Class 3A thread fit addresses critical alignment challenges in precision assemblies. The alloy steel construction combined with Rockwell C32 hardness ensures dimensional stability under mechanical stress, preventing deformation in high-cycle applications. The precisely machined shoulder with 1/8" diameter and 3/8" length provides accurate pivot points and bearing surfaces in machinery, while the headless design with slotted drive maintains clean profiles in compact spaces. These industrial shoulder screws are engineered to solve alignment and wear issues in rotating assemblies, precision instruments, and mechanical linkages where right-hand coarse threading facilitates efficient assembly operations.

Specification Summary & Compliance

This precision shoulder screw features 4-40 UNC coarse threading with Class 3A fit for superior thread engagement. Critical dimensions include shoulder diameter of 1/8" (-0.001" to 0" tolerance) and shoulder length of 3/8" (0" to 0.005" tolerance) ensuring precise component alignment. Manufactured from alloy steel with Rockwell C32 hardness for durability. Fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, meeting international standards for industrial fasteners.