S-91257A929 7/8"-9 x 7" ASME B18.2.1, SAE J429 High-Strength Grade 8 Steel Hex Head Screws
High-Strength Grade 8 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
- Exceptional tensile strength of 150,000 PSI ensures reliable performance in high-stress applications, reducing the risk of fastener failure.
- Superior corrosion resistance from zinc yellow-chromate plating extends service life in harsh industrial environments, minimizing maintenance needs.
- High hardness (Rockwell C33) provides excellent wear resistance, maintaining thread integrity and drive engagement over repeated use.
- Coarse UNC threading allows for faster installation and easier alignment, saving time and labor costs in assembly operations.
- Class 2A thread fit ensures consistent, reliable engagement with standard nuts and tapped holes, promoting secure connections.
- Partially threaded design offers optimal clamping force distribution, ideal for applications requiring precise joint compression.
- External hex drive enables high-torque installation with common tools, facilitating quick and secure fastening in confined spaces.
Professional Applications & Engineering Value
This Grade 8 hex head screw is engineered to address critical challenges in heavy machinery, structural steel connections, and industrial equipment assembly. The steel construction combined with zinc yellow-chromate plating provides robust protection against rust and chemical exposure, making it suitable for outdoor and corrosive environments. Its coarse UNC thread resists vibration loosening and simplifies installation in field conditions, while the partial threading ensures maximum grip length without compromising shear strength. Ideal for construction, automotive, and manufacturing sectors, this fastener delivers reliable performance where high tensile strength and durability are non-negotiable, reducing downtime and replacement costs.
Specification Summary & Compliance
This screw adheres to Class 2A thread fit tolerances and UNC coarse thread standards, ensuring precise dimensional accuracy. It meets ASME B18.2.1 and SAE J429 specifications for consistent manufacturing quality. The product is fully compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, guaranteeing environmental safety and regulatory acceptance in global markets.
