S-91205A564 1/4"-28 x 7/8" ASME B18.3, ASTM A574 Alloy Steel Thread-Locking Socket Head Screws
Alloy Steel Thread-Locking 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
- Permanent vibration resistance with nylon patch thread locker that eliminates the need for separate locking hardware
- Exceptional tensile strength of 170,000 psi provides reliable performance in high-stress applications
- Superior corrosion protection from the black-oxide finish on alloy steel, enhancing durability
- Precise Class 3A thread fit ensures smooth installation and secure fastening in demanding assemblies
- Wide temperature tolerance from -70° to 250°F maintains locking integrity in varied environments
- Secure hex drive engagement with 3/16" drive size allows for high-torque installation without slippage
- Full thread coverage along the 7/8" length offers consistent clamping force and versatile positioning
Professional Applications & Engineering Value
This 1/4"-28 UNF socket head cap screw is engineered to solve critical industrial challenges, such as component loosening under vibration and thermal cycling. The permanent nylon patch thread locker provides reliable locking without additional components, ideal for machinery, automotive, and aerospace assemblies where maintenance access is limited. Manufactured from black-oxide alloy steel, it resists corrosion while maintaining high tensile strength and hardness (Rockwell C37), ensuring long-term performance in harsh conditions. The fine UNF threads and Class 3A fit deliver precise engagement, reducing the risk of cross-threading and improving assembly efficiency in precision equipment.
Specification Summary & Compliance
This screw features a Class 3A thread fit with UNF fine threads (1/4"-28) and right-hand direction for standardized assembly. It complies with ASME B18.3 and ASTM A574 specifications, ensuring dimensional accuracy and manufacturing consistency. Additionally, it meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) compliance standards, supporting environmentally responsible sourcing and use in regulated industries.
