S-90550A240 4-40 x 1/2" ASME B18.3, ASTM F879, MIL-DTL-18240 Venting Stainless Steel Hex-Drive Flat Head Screws
Venting Stainless Steel Hex-Drive Flat Head 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, ideal for harsh industrial environments
- Precise Class 3A thread fit ensures reliable engagement and vibration resistance in critical assemblies
- Vented design (0.035" diameter) prevents pressure buildup and allows for fluid/gas passage in specialized applications
- 82° countersink angle provides flush mounting for clean, aerodynamic, and snag-free surfaces
- Hex drive (1/16") compatibility enables high-torque installation with standard tools, reducing stripping risks
- Full threading along 1/2" length maximizes grip strength and load distribution across the entire fastener
- Compliance with major standards including ASME B18.3, ASTM F879, and MIL-DTL-18240 guarantees consistent quality
Professional Applications & Engineering Value
Engineered for precision-critical industries, these 4-40 UNC flat head screws address common challenges in aerospace, electronics, and machinery assembly. The 18-8 stainless steel material offers excellent resistance to oxidation and chemical exposure, while the coarse thread spacing facilitates quicker installation in softer materials or blind holes. The vented feature is particularly valuable in pressurized systems or environments requiring drainage, preventing failure due to trapped moisture or air. With a Class 3A thread fit, these screws maintain tight tolerances for high-vibration applications, reducing maintenance needs and enhancing operational reliability. Their compliance with RoHS 3 and REACH ensures they meet global environmental and safety standards.
Specification Summary & Compliance
This 4-40 UNC flat head screw features a 1/2" length with fully threaded coarse spacing and precise Class 3A thread fit for superior mechanical performance. It meets ASME B18.3, ASTM F879, and MIL-DTL-18240 specifications, ensuring dimensional accuracy and manufacturing consistency. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, confirming its suitability for use in regulated industries without hazardous substance restrictions.
