S-93310A108 4-40 x 3/8" ASME B18.3, ASTM F879, MIL-DTL-18240 Thread-Locking Stainless Steel Button Head Hex-Drive Screws
Thread-Locking Stainless Steel Button Head Hex-Drive 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 permanent nylon patch ensures reliable fastening in high-stress environments
- Superior corrosion resistance from 18-8 stainless steel construction for extended service life in harsh conditions
- High mechanical strength with 70,000 psi tensile strength and Rockwell B55 hardness withstands demanding loads
- Wide temperature tolerance (-70° to 250°F) maintains performance across extreme thermal cycles
- Precision threading with Class 3A fit and UNC coarse threads provides secure engagement and easy installation
- Optimized drive design with 1/16" hex drive enables efficient torque application and reduced stripping risk
- Comprehensive compliance meets ASME B18.3, ASTM F879, and MIL-DTL-18240 standards for quality assurance
Professional Applications & Engineering Value
Engineered for demanding industrial applications, these 4-40 UNC nylon patch locking screws solve critical vibration-induced loosening problems in machinery, electronics, and aerospace assemblies. The permanent nylon patch locking technology creates consistent friction resistance without compromising the 18-8 stainless steel integrity, ensuring reliable performance in corrosive environments. The rounded button head profile provides a low-profile finish while the coarse UNC threading enables rapid installation in various materials. With fully threaded shank design and hex drive compatibility, these fasteners deliver superior clamping force distribution and torque transmission for high-vibration applications where maintenance access is limited.
Specification Summary & Compliance
This 4-40 UNC screw features precision Class 3A thread fit with coarse thread spacing and right-hand threading. Manufactured to ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring dimensional accuracy and performance reliability. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental and safety standards for industrial use.
