S-90420A665 1/4"-20 x 3" Tapping Screws

Key Features & Benefits at a Glance

• Superior corrosion resistance with 18-8 stainless steel construction and galvanic-barrier coating for extended service life in harsh environments
• Eliminates pre-drilling requirements thanks to the integrated drilling tip that penetrates up to 0.21" thickness in steel and sheet metal
• Enhanced holding power and stability from the flanged design that distributes load and prevents pull-through
• Quick installation and high torque capability with external hex drive and coarse UNC threads for faster driving and secure fastening
• Optimized thread engagement through thread forming (CSD) design that creates strong, permanent threads in base materials
• Versatile material compatibility specifically engineered for use in steel, stainless steel, and sheet metal applications
• Reliable partial threading ensures precise clamping force control while minimizing thread damage during installation

Professional Applications & Engineering Value

These galvanic-barrier coated stainless steel tapping screws solve critical industrial fastening challenges by combining material excellence with intelligent design. The 18-8 stainless steel core provides inherent corrosion resistance, while the specialized coating creates an additional barrier against galvanic corrosion when joining dissimilar metals. The thread forming CSD design with UNC coarse threads eliminates the need for tapped holes, reducing installation time and labor costs in steel, stainless steel, and sheet metal assemblies. The integrated drilling tip (No. 3 type) penetrates up to 0.21" thickness without pre-drilling, preventing material displacement and ensuring precise hole alignment. This makes them ideal for HVAC systems, electrical enclosures, metal framing, and industrial equipment where vibration resistance, corrosion protection, and installation efficiency are paramount.

Specification Summary & Compliance

This 1/4"-20 x 3" tapping screw features UNC coarse threads with standard Class 2A thread tolerances for reliable engagement. The partially threaded design provides controlled clamping, while the flanged hex head with external drive ensures secure installation. Manufactured from 18-8 stainless steel with galvanic-barrier coating, these screws comply with industry standards for thread forming screws (CSD type) and meet RoHS and REACH environmental requirements for industrial use.