Description: 13Pcs HSS Drill Bit Set 1.5-6.5mm Twist Drill Bit 1/16’’-1/4’’ Inch Hex Shank Drive Quick Change High Speed For Drill Machine Chuck
A twist drill is a metal rod of a specific diameter that has two, three or four spiral flutes running most of its length. Two-flute drills are for primary drilling, whereas three- and four-flute drills are only for enlarging cast or punched holes in a production situation. The section between the two flutes is called the web, and a point is formed by relief grinding the web to an angle of 59° from the drill’s axis, which is 118° inclusive. This forms a sloped cutting edge at the edge of the flute, which is called the lip. A twist drill is very inefficient at the point because the web leaves scant exit space for debris (called swarf) and because the point has a low surface speed compared to the periphery. For this reason, a good scheme for drilling larger holes is to first drill 1/4″ or less and then follow with the drill of the desired diameter.
100% brand new and high quality.
This set of durable 13 piece drill bits lasts six times longer than standard drill bits.
Titanium coating facilitates faster penetration with less effort.
Suitable for use with sheet iron, aluminum, copper, wood, plastic etc.(Not for stainless steel and other high hardness metal.)
High hardness, high wear-resistance and high toughness.
The one-in-all formation of grinding, precise size, long lifespan, durable.
1 x 13Pcs HSS Drill Bit Set 1.5-6.5mm Twist Drill Bit 1/16’’-1/4’’ Inch Hex Shank Drive Quick Change High Speed For Drill Machine Chuck