NEW DESIGN OF ONE STEP FOR BOTH OF WINGS AND DRILLING POINT

SPIRAL THREAD TO THE WINGS END HELP MUCH MORE EFFICT IN PENETRATION AND CHIPS REMOVING, ESPECIALLY FOR APPLICATION OF HARD WOOD AND THICK METAL PLATE.

BEST PERFORMANCE ON THICKNESS OF HARD WOOD 3/4"~1-1/8",

AND METAL PLATE 2MM~6MM

SCREW DIMENSION: #6(M3.5)~5/16(M8)

SCREW LENGTH:1"(25MM)~4"(100MM)