S-91309A505 1/4"-28 x 3/4" ASME B18.2.1, SAE J429 Low-Strength Steel Hex Head Screws
Low-Strength Steel Hex 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 zinc plating for extended service life in harsh industrial environments
- High tensile strength of 60,000 psi ensures reliable fastening under heavy loads and vibration
- Rockwell B69 hardness provides excellent durability and resistance to wear and deformation
- Precision Class 2A thread fit guarantees smooth assembly and consistent torque performance
- UNF fine threading offers superior vibration resistance compared to coarse thread alternatives
- External hex drive design enables easy installation with standard tools and high torque application
- Full threading along the entire 3/4" length provides maximum grip and adjustment flexibility
Professional Applications & Engineering Value
These 1/4"-28 UNF hex head screws deliver exceptional engineering value in demanding applications where vibration resistance and corrosion protection are critical. The steel construction with zinc plating creates a robust barrier against environmental factors, while the fine UNF threading maintains secure fastening in high-vibration machinery, automotive assemblies, and industrial equipment. The external hex drive allows for high-torque installation without stripping, and the Class 2A thread fit ensures precise engagement for consistent clamping force. These fully threaded screws are engineered to prevent loosening under dynamic loads, making them ideal for critical joints in manufacturing, construction, and heavy equipment where reliability is paramount.
Specification Summary & Compliance
This 1/4"-28 UNF hex head screw features precise Class 2A thread fit tolerances and complies with ASME B18.2.1 manufacturing specifications. The product meets RoHS 3 (2015/863/EU) compliance for hazardous substance restrictions and REACH (EC 1907/2006) regulations for chemical safety. With 60,000 psi tensile strength and Rockwell B69 hardness, these screws maintain dimensional accuracy and performance consistency across industrial applications.
