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.
- Undercut-indented hex washer slotted head always seats flush.
- Full 1/4 in. (No. 8) head will not strip out of hex driver opening at any-time during operation.
- Complete operator control with precise hole alignment.
- Combination lead double thread Instantly penetrates and engages in heavy gauge sheet metal and layered light gauge.
- Starting thread machined down to very tip of screw point.
- Undercut-indented hex washer slotted head always seats flush.
- Full 1/4 in. (No. 8) head will not strip out of hex driver opening at any-time during operation.
- Complete operator control with precise hole alignment.
- Combination lead double thread Instantly penetrates and engages in heavy gauge sheet metal and layered light gauge.
- Starting thread machined down to very tip of screw point.