S-90910A721 4-40 x 5/8" ASME B18.3 Stainless Steel Button Head Torx Screws
Stainless Steel Button Head Torx 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
- Superior corrosion resistance with 18-8 stainless steel construction and passivated finish, ideal for harsh industrial environments
- Enhanced torque transmission through T8 Torx drive design, minimizing cam-out and tool wear during installation
- Precise Class 3A thread fit ensures secure fastening with reduced risk of cross-threading in critical assemblies
- High tensile strength rating of 60,000 psi provides reliable performance under mechanical stress and vibration
- Optimized button head profile offers low-profile clearance while maintaining excellent bearing surface
- Full threading along 5/8" length enables maximum grip range and adjustment flexibility
- Compliance with ASME B18.3 standards guarantees consistent dimensional accuracy and interchangeability
Professional Applications & Engineering Value
Engineered for precision assemblies requiring reliable fastening under demanding conditions, these 4-40 UNC Torx screws combine 18-8 stainless steel's inherent corrosion resistance with a passivated surface treatment for enhanced protection against chemical exposure and oxidation. The T8 drive system delivers superior torque transfer compared to traditional drives, reducing installation errors in automated or high-volume production environments. With Class 3A thread tolerances and coarse thread spacing, these fully threaded button head screws provide exceptional pull-out resistance in materials ranging from metals to engineered plastics, making them ideal for electronics enclosures, machinery guards, and precision instrumentation where vibration resistance and consistent clamp load are critical.
Specification Summary & Compliance
Manufactured to ASME B18.3 specifications with Class 3A thread fit and UNC coarse thread profile. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations. Mechanical properties include Rockwell B55 hardness and 60,000 psi tensile strength.
