S-90390A148 1/4"-20 x 3/4" Tapping Screws

Key Features & Benefits at a Glance

• Superior thread cutting performance for reliable, self-tapping installation in aluminum, brass, cast iron, and sheet metal without pre-threading.
• Enhanced corrosion resistance with zinc-plated steel construction, extending service life in demanding industrial environments.
• Secure, high-torque driving provided by the T27 Torx drive, reducing cam-out and tool slippage for efficient assembly.
• Flush, low-profile seating with a standard flat head and 82° countersink angle for a smooth, finished surface.
• Robust UNC coarse threading ensures quick engagement and strong holding power in a wide range of materials.
• Full 3/4" length and complete threading offer maximum grip and uniform stress distribution along the entire fastener.
• Compliance with RoHS 3 standards guarantees environmentally safe materials for global manufacturing and supply chain requirements.

Professional Applications & Engineering Value

These 1/4"-20 T27 Torx flat head tapping screws are engineered to solve common fastening challenges in metal fabrication and assembly. The thread cutting (Type F) design and zinc-plated steel material work together to create durable, permanent threads in aluminum, brass, cast iron, and sheet metal, eliminating the need for separate tapping operations and reducing assembly time. The Torx T27 drive allows for higher torque application with minimal risk of stripping, which is critical in automated or high-volume production lines. Combined with the 82° countersink angle and UNC coarse thread, these screws provide a secure, vibration-resistant connection that maintains integrity under stress, making them ideal for construction, machinery, and metalworking applications where reliability is non-negotiable.

Specification Summary & Compliance

This screw features a 1/4"-20 UNC coarse thread with standard Class 2A tolerances for consistent fit. It is fully threaded with a blunt tip and right-hand thread direction, designed as a Type F thread cutting screw for use with a No. 1 drill bit (0.228" diameter). The product is manufactured in compliance with RoHS 3 (2015/863/EU), ensuring it meets strict environmental and safety regulations for hazardous substance restrictions.