S-91286A109 1/4"-20 x 7/8" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws
High-Strength Grade 8 Steel Hex Head Screws
Image may differ from product. See technical specification for details.
Basic Information
Head Parameters
Dimensions
Thread Parameters
Tip & Drive Parameters
Material & Strength
Temperature & Environment
- Fast delivery
- Enjoy discounts on bulk purchases
- Secure Payment
- Fast Global Shipping
Key Features & Benefits at a Glance
- Exceptional load-bearing capacity with 150,000 psi tensile strength for reliable performance in high-stress applications
- Superior corrosion protection through zinc-flake coating that withstands harsh industrial environments
- Optimized torque transmission with external hex drive design for secure installation and removal
- Enhanced thread engagement with UNC coarse threading that resists vibration loosening
- Precision manufacturing with Class 2A thread fit ensuring consistent performance and easy assembly
- Maximum material strength from Grade 8 classification with Rockwell C33 hardness for long-term durability
- Full-length threading providing complete engagement along the entire 7/8" length for superior holding power
Professional Applications & Engineering Value
These Grade 8 hex head screws deliver critical performance in demanding industrial settings where failure is not an option. The high-strength steel construction combined with Rockwell C33 hardness ensures these fasteners maintain integrity under extreme mechanical stress, making them ideal for heavy machinery, structural assemblies, and automotive applications. The zinc-flake coating provides superior corrosion resistance that outperforms conventional platings, extending service life in challenging environments. With UNC coarse threads and Class 2A fit, these screws offer excellent vibration resistance while maintaining easy installation - solving common challenges of joint integrity and maintenance efficiency in industrial fastening systems.
Specification Summary & Compliance
Manufactured to precise dimensional standards with Class 2A thread fit and UNC coarse threading (1/4"-20). Complies with ASME B18.2.1 and SAE J429 specifications for Grade 8 fasteners. Meets environmental compliance standards including RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations. Features external hex drive with 7/16" head width and 5/32" head height for standardized tool compatibility.
