S-91870A711 4-40 x 1/4" ASME B18.3 Tamper-Resistant Torx Stainless Steel Flat Head Screws

Key Features & Benefits at a Glance

• Enhanced tamper resistance with Torx T10 drive for secure installations in restricted-access environments
• Superior corrosion protection from 18-8 stainless steel construction and passivated finish for long-term reliability
• High-load bearing capacity with 70,000 psi tensile strength and Rockwell B70 hardness for demanding applications
• Precision thread engagement through Class 3A fit and UNC coarse threading for vibration-resistant fastening
• Flush mounting capability with standard 82° countersink angle and flat head design for smooth surface profiles
• Full-length threading ensures maximum grip along the entire 1/4" shaft length
• Regulatory compliance meets ASME B18.3 specifications and international environmental standards

Professional Applications & Engineering Value

Engineered for critical security applications, these 4-40 UNC flat head screws with tamper-resistant Torx T10 drive provide reliable protection against unauthorized access in public infrastructure, electronic enclosures, and industrial equipment. The 18-8 stainless steel material combined with passivated finish delivers exceptional corrosion resistance in harsh environments, while the Class 3A thread fit ensures precise, vibration-resistant connections. The flat head design with 82° countersink creates seamless surface integration, making these fully threaded screws ideal for applications requiring both security and aesthetic considerations.

Specification Summary & Compliance

Manufactured to ASME B18.3 specifications with Class 3A thread fit and UNC coarse thread spacing. Features include right-hand threading, standard flat head profile, and dimensional accuracy with 0.255" head diameter and 1/4" length. Compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) environmental regulations, ensuring safe use across global markets.