A unique thread design and quality controlled manufacture spell the Zip-In difference. Zip-In's sophisticated heat treat process allows the screw to taper to a fine, sharp point without sacrificing critical point strength. A single starting thread is formed down to the very tip of the point and is the source of Zip-In's penetrating power. A second thread above the point engages after initial penetration and drills in the screw double fast. Zip-In screws are faster driving, with a greater capacity for fastening heavier gauges of sheet metal than any other self-piercing type.

Malco® Zip-In Sheet Metal Screw, #8 Thread, Double Thread, 1/4 in Dia Head, Hexagonal Washer Head, Slotted Drive, 3 in L Thread, White Bright Zinc-Plated

• Undercut indented hex washer slotted head
• Burr-free
• Full 1/4 in (# 8) head will not strip out of hex driver opening
• One 1/4 in hex driver accommodates all sizes
• Undercut - always seats flush
• Some screws sizes available in pails
• Trademarked and patented head markings indicate one and only genuine zip-ins
• Combination lead double thread design: single starting thread machined down to very tip of screw point, instantly penetrates and engages in heavy gauge sheet metal and layered light gauge
• Consistent hard point quality controlled heat treat
• Sharp tapered point will not mushroom or break
• No walking

• Video Link https://youtu.be/s-iC8Zp8zKg