S-91857A535 1/4"-20 x 3/8" ASME B18.6.3 Stainless Steel Round Head Slotted Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance in harsh chemical environments thanks to 316 stainless steel construction with passivated surface treatment
• Exceptional mechanical strength with 100,000 psi tensile strength and Rockwell B100 hardness for reliable performance under heavy loads
• Precise thread engagement with Class 2A UNC coarse threads ensuring consistent fastening and vibration resistance
• Full threading capability along the entire 3/8" length for maximum grip and uniform stress distribution
• Industry-standard compliance with ASME B18.6.3 specifications for dimensional accuracy and interchangeability
• Environmental regulation adherence meeting RoHS 3 and REACH requirements for safe industrial usage
• Traditional slotted drive design providing reliable installation with standard screwdriver tools

Professional Applications & Engineering Value

This 316 stainless steel rounded head screw delivers critical performance advantages in demanding industrial settings where corrosion resistance and mechanical integrity are paramount. The combination of UNC coarse threading and Class 2A fit ensures rapid installation with excellent vibration resistance, while the passivated finish significantly enhances the material's natural resistance to chlorides, acids, and other aggressive chemicals. Engineers specify these fully threaded machine screws for chemical processing equipment, marine hardware, food processing machinery, and pharmaceutical applications where ASME B18.6.3 compliance guarantees dimensional consistency across replacement components. The rounded head profile distributes clamping force evenly while the slotted drive accommodates both manual and automated assembly processes.

Specification Summary & Compliance

This fastener maintains Class 2A thread tolerances per UNC standards with precise dimensional control including 0.25" thread diameter and 3/8" length. Manufacturing adheres to ASME B18.6.3 specifications for rounded head machine screws. Regulatory compliance includes RoHS 3 (2015/863/EU) restrictions on hazardous substances and REACH (EC 1907/2006) chemical safety requirements, ensuring environmental responsibility and workplace safety.