S-90400A311 4-40 x 5/16" ASME B18.13 Steel Pan Head Phillips Screws with Spring Lock Washer
Steel Pan Head Phillips Screws with Spring Lock Washer
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Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Washer & Nut
Material & Strength
Temperature & Environment
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Key Features & Benefits at a Glance
- Enhanced corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
- Superior vibration resistance through integrated spring lock washer, preventing loosening under dynamic loads
- High-strength performance with 60,000 PSI tensile strength and Rockwell B70 hardness for reliable fastening in critical applications
- Quick installation and removal with No. 1 Phillips drive and fully threaded coarse UNC design
- Optimized load distribution through rounded pan head profile, minimizing surface damage during tightening
- Precision thread fit with Class 2A tolerance ensuring consistent engagement and reliable clamping force
- Regulatory compliance meeting ASME B18.13 standards for dimensional accuracy and material specifications
Professional Applications & Engineering Value
These 4-40 UNC zinc-plated steel screws with integrated spring lock washers provide essential vibration-resistant fastening solutions for industrial equipment, machinery assemblies, and electronic enclosures. The rounded pan head design distributes clamping force evenly while the coarse thread configuration enables rapid installation in various materials. The zinc-plated finish offers reliable corrosion protection in moderate environments, while the fully threaded shank ensures maximum engagement depth. Particularly valuable in applications requiring repeated disassembly, the Phillips drive system combined with the locking washer mechanism maintains joint integrity under cyclic loading conditions common in manufacturing and maintenance operations.
Specification Summary & Compliance
Manufactured to precise Class 2A thread fit tolerances with UNC coarse threads measuring 4-40 size. Compliant with ASME B18.13 specifications for dimensional accuracy and mechanical properties. Meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use in industrial applications worldwide. The spring lock washer component maintains consistent performance within specified torque ranges while the zinc-plated steel construction provides durable corrosion protection.
