S-91771A557 1/4"-28 x 1/2" ASME B18.6.3 Stainless Steel Phillips Flat Head Screws
Stainless Steel Phillips Flat 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
- Superior corrosion resistance with passivated 18-8 stainless steel construction, ideal for harsh industrial environments
- High tensile strength of 80,000 psi ensures reliable performance under heavy loads and vibration
- Precision Class 2A thread fit guarantees smooth installation and secure fastening in fine-thread applications
- Fully threaded design provides maximum grip and load distribution along the entire length
- 82° countersink angle and flat head profile enable flush mounting for clean, professional finishes
- Phillips No. 3 drive offers efficient torque transfer and reduced cam-out during installation
- Compliance with ASME B18.6.3, RoHS 3, and REACH ensures quality, safety, and environmental responsibility
Professional Applications & Engineering Value
These 1/4"-28 UNF flat head screws are engineered to address critical challenges in industrial assembly, where corrosion resistance, high tensile strength, and precise thread fit are paramount. The passivated 18-8 stainless steel material combats rust and chemical exposure, extending service life in demanding settings like machinery, automotive, and outdoor equipment. The fine UNF threads and Class 2A fit provide superior holding power in thin materials, reducing the risk of stripping. With an 82° countersink angle, they sit flush to prevent snagging and improve aesthetics, while the Phillips drive ensures quick, secure installation. Ideal for applications requiring RoHS and REACH compliance, these screws deliver reliability where regulatory standards and durability are non-negotiable.
Specification Summary & Compliance
This screw features a 1/4"-28 UNF fine thread with Class 2A fit for precise dimensional accuracy, a fully threaded right-hand design, and mechanical properties including 80,000 psi tensile strength and Rockwell B80 hardness. It conforms to ASME B18.6.3 manufacturing specifications and meets RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulatory requirements, ensuring environmental safety and industry-standard performance.
