S-90402A108 4-40 x 3/8" ASME B18.13 Steel Pan Head Phillips Screws with External-Tooth Lock Washer
Steel Pan Head Phillips Screws with External-Tooth Lock Washer
Image may differ from product. See technical specification for details.
Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Washer & Nut
Material & Strength
Temperature & Environment
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Key Features & Benefits at a Glance
- Superior vibration resistance with integrated external-tooth lock washer that maintains clamping force under dynamic loads
- Enhanced corrosion protection through zinc-plated steel construction for extended service life in industrial environments
- High tensile strength of 60,000 psi ensures reliable performance in demanding applications
- Quick installation and removal with Phillips No. 1 drive and coarse UNC threading for efficient assembly
- Consistent thread engagement through Class 2A thread fit and fully threaded design
- Secure locking capability with external-tooth washer that prevents loosening in high-vibration settings
- Industry-standard compliance meeting ASME B18.13 specifications for reliable performance
Professional Applications & Engineering Value
These 4-40 UNC zinc-plated steel screws with external-tooth lock washers provide critical vibration resistance in industrial assemblies where loosening can compromise safety and performance. The coarse thread design enables faster installation in various materials while maintaining Class 2A thread fit precision. The integrated lock washer creates continuous spring tension that counters vibrational forces, making these rounded head Phillips screws ideal for machinery, electrical enclosures, and automotive components. The zinc-plated steel construction offers corrosion resistance while the 60,000 psi tensile strength ensures structural integrity in high-stress applications. The fully threaded design maximizes thread engagement for superior holding power across the entire fastener length.
Specification Summary & Compliance
Manufactured to precise Class 2A thread fit tolerances with 4-40 UNC coarse threads and right-hand threading. Complies with ASME B18.13 manufacturing standards and features Rockwell B69 hardness rating. Meets environmental regulations including RoHS 3 (2015/863/EU) compliance and REACH (EC 1907/2006) compliance for restricted substance control. The external-tooth lock washer provides reliable locking performance with 0.23" OD and 0.018" thickness specifications.
