S-93310A721 4-40 x 3/16" 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 nylon patch thread locker ensures reliable fastening in dynamic environments from -70° to 250°F
- Superior corrosion resistance from 18-8 stainless steel construction maintains integrity in harsh industrial conditions
- Precise Class 3A thread fit delivers consistent engagement and reduced assembly issues in critical applications
- High-strength performance with 70,000 psi tensile strength and Rockwell B55 hardness withstands heavy mechanical loads
- Quick installation through 1/16" hex drive design allows efficient assembly with standard tools
- Full threading coverage provides maximum grip length and uniform stress distribution
- Regulatory compliance meets MIL-DTL-18240 specifications while being RoHS 3 and REACH compliant
Professional Applications & Engineering Value
Engineered for demanding industrial applications, these 4-40 UNC rounded head screws solve critical fastening challenges where vibration resistance and corrosion protection are paramount. The 18-8 stainless steel construction combined with Class 3A thread precision ensures reliable performance in machinery, electronics, and aerospace assemblies. The integrated nylon patch thread locker prevents loosening under continuous vibration, eliminating the need for secondary locking components. With coarse UNC threading and fully threaded design, these button head screws provide rapid installation and superior holding power in tight spaces, making them ideal for maintenance-critical equipment and precision instruments where downtime is unacceptable.
Specification Summary & Compliance
This 4-40 UNC screw features precise Class 3A thread fit with coarse thread spacing and right-hand threading. Manufacturing complies with MIL-DTL-18240 specifications, ensuring consistent quality and performance. The product is fully RoHS 3 (2015/863/EU) Compliant and REACH (EC 1907/2006) Compliant, meeting international environmental standards for industrial use.
