.Classic high speed steel（4241） with titanium coating for proven capability and durability in drilling holes in plastic, aluminum, copper, stainless steel and many   other types of sheet metal；

.135° Split point tip: increases cutting speed with self-centering and prevents walking；

.Two-flute design: clears chips faster and allows particles to escape easily；

.1/4" hex shank (6.35mm) can be easily fit into power driver, drill and press drill；

.Includes 10 Step Sizes:9、12、15、18、21、24、27、30、33、36mm