S-90275A558 1/4"-28 x 5/8" ASME B18.6.3 Steel Slotted Flat Head Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments
• Precise flush mounting enabled by standard 82° countersink angle and flat head design for seamless surface integration
• Enhanced thread engagement through Class 2A fine thread fit (1/4"-28 UNF) ensuring vibration-resistant, secure fastening
• Exceptional mechanical strength with 60,000 psi tensile strength and Rockwell B70 hardness for heavy-duty applications
• Full-threaded right-hand design providing maximum grip length and consistent load distribution across the entire fastener
• Tool-friendly installation with slotted drive style accommodating standard screwdrivers for quick assembly
• Regulatory compliance assurance meeting ASME B18.6.3 specifications and international environmental standards (RoHS 3 & REACH)

Professional Applications & Engineering Value

These 1/4"-28 UNF flat head screws deliver critical engineering solutions where surface-flush fastening and high tensile strength are paramount. The zinc-plated steel construction provides essential corrosion protection for machinery, automotive assemblies, and electrical enclosures exposed to harsh conditions. The fine thread spacing and Class 2A thread fit ensure superior vibration resistance in dynamic applications, while the 82° countersink angle allows for seamless integration in precision-machined components. With full threading and 60,000 psi tensile strength, these slotted flat head screws maintain joint integrity under sustained mechanical stress, making them ideal for critical industrial fastening where reliability cannot be compromised.

Specification Summary & Compliance

Manufactured to exact ASME B18.6.3 specifications with Class 2A thread fit tolerances ensuring precise dimensional accuracy. The 1/4"-28 UNF fine thread configuration maintains standardized compatibility across industrial applications. Full compliance with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations guarantees safe usage in regulated industries. The 82° countersink angle adheres to industry-standard profiles for consistent performance in countersunk applications.