S-91205A536 1/4"-20 x 7/16" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws
Alloy Steel Thread-Locking Socket 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
- Vibration-resistant locking with permanent Nylon Patch thread locker that maintains integrity from -70° to 250°F
- Exceptional tensile strength of 170,000 psi for heavy-duty applications and high-stress environments
- Precise Class 3A thread fit ensuring superior engagement and reduced risk of cross-threading in assembly
- Corrosion-resistant black-oxide finish on alloy steel for enhanced durability in demanding industrial conditions
- Reliable hex drive compatibility with 3/16" drive size for secure tool engagement and reduced cam-out
- Full thread coverage along the 7/16" length for consistent clamping force and versatile mounting options
- High hardness rating of Rockwell C37 providing excellent wear resistance and long service life
Professional Applications & Engineering Value
This black-oxide alloy steel socket head cap screw delivers critical performance where vibration resistance and structural integrity are paramount. The permanent Nylon Patch thread locker effectively prevents loosening under dynamic loads, making it ideal for machinery, automotive assemblies, and precision equipment subjected to constant motion or thermal cycling. Engineered with Class 3A UNC coarse threads, it ensures rapid installation and reliable fastening in high-volume production environments. The combination of 170,000 psi tensile strength and Rockwell C37 hardness provides exceptional load-bearing capacity for critical joints, while the black-oxide surface treatment offers additional protection against corrosion in industrial settings. These socket head cap screws solve common engineering challenges of fastener failure, maintenance downtime, and assembly inconsistency.
Specification Summary & Compliance
Manufactured to exacting ASME B18.3 specifications with ASTM A574 material standards, these screws feature Class 3A thread fit for precision engagement and UNC coarse thread spacing for efficient assembly. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets. Thread specifications include 1/4"-20 UNC right-hand threads with standard socket head profile and 3/16" hex drive compatibility.
