Box of 100. 4-40 x 3/8 Slotted H/W Zinc Plated Swageform® Swageform® Is THE High Performance Threadforming Screw. Swageform® thread forming screws have been superior performers in automotive, industrial, and consumer assembles for over 25 years, yet they still represent the most efficient, cost-effective concept in thread-forming screw design. Although many improvements have been made in the product's performance, the principle behind its sucesss is as applicaple and as flawless today as it was at its inception, and will remain so as long as thread forming features are a necessity to modern assembly methods. Swageform® screws very simply, exhibit performance capabilities and economies far beyond those of thread-forming and thread-cutting tapping screws. Swageform® thread forming screws allow you to eliminate the tapping process as the screw will form your threads during installation-if you are tapping holes into metals,consider the savings of eliminating a costly process step.