S-91251A089 1/4"-20 x 4 1/2" ASTM A574 Alloy Steel Socket Head Screws
Alloy Steel Socket 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 tensile strength of 170,000 psi ensures reliable performance under high-stress conditions, reducing the risk of fastener failure.
- Corrosion-resistant black-oxide finish on alloy steel provides enhanced durability and longevity in harsh industrial environments.
- Precise Class 3A thread fit guarantees tight, secure fastening with minimal play, improving assembly accuracy.
- Partially threaded design allows for controlled clamping force and easier alignment in applications requiring specific grip lengths.
- Hex socket drive with 3/16" drive size enables high-torque installation and removal, reducing tool slippage and damage.
- UNC coarse threading offers quick assembly and superior resistance to vibration loosening in demanding applications.
- Compliance with ASTM A574, RoHS 3, and REACH ensures material consistency, environmental safety, and regulatory acceptance for global use.
Professional Applications & Engineering Value
This Black-Oxide Alloy Steel Socket Head Cap Screw is engineered to address critical challenges in industrial assembly, such as vibration-induced loosening and corrosion. The UNC coarse thread and Class 3A fit provide a robust grip in materials like steel and aluminum, making it ideal for machinery, automotive, and heavy equipment applications. Its partially threaded rod type allows precise load distribution, reducing stress concentration. With a Rockwell C37 hardness and 170,000 psi tensile strength, it withstands extreme mechanical loads while the black-oxide surface resists rust, extending service life in humid or abrasive conditions. These features ensure reliable performance in high-tensile strength and corrosion-resistant fastening needs, minimizing maintenance downtime.
Specification Summary & Compliance
This fastener adheres to Class 3A thread fit for precise dimensional accuracy and UNC coarse thread standards. It meets ASTM A574 specifications for high-strength alloy steel socket head cap screws, ensuring consistent manufacturing quality. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, it supports environmental and health safety standards for industrial use.
