CUTTING & DRILLING LESSON 1: What's the Best Drill Bit for Your Job?
CHOOSING THE BEST BIT FOR YOUR JOB
CHOOSING A DRILL POINT ANGLE
135° Drill Points with Split Point: For daily use in the shop or on the jobsite we recommend using a 135° bit. They are ideal for general purpose drilling in higher grade steel, work-hardening Stainless steels, aluminum, wood, brass and plastic. 135° bits have a flatter point with a longer cutting edge that more aggressively removes material. This is a critical feature that helps prevent work hardening, particularly in stainless steel. The Split Point feature of our 135° bits minimizes surface walking when starting a hole and promotes a straighter cut, particularly useful when drilling using hand-held tools.
118° Drill Points: For consumer or retail grade drill bits the 118-degree angle is most common due to it’s lower cost of manufacture. The 118° bits are suitable for general purpose drilling in softer materials such as low carbon steels, aluminum, wood, brass and plastic. When used with a hand-held tool these bits will "walk" on harder materials such as stainless steel and steel and generally require the use of a center punch to keep them in place for the initial cut.
POPULAR DRILL BIT MATERIALS
High-Speed Steel (HSS) is a popular material good for drilling into most steels as well as wood and plastic. High quality HSS bits like our Ultra-Bor series can successfully drill stainless steel when used correctly. HSS bits are the economical choice for most shop and maintenance drilling applications.
Cobalt is considered an upgrade from HSS for some applications due to the addition of Cobalt to the drill material. Cobalt bits feature higher resistance to heat and can hold their edge sharpness longer when drilling materials that are prone to work hardening, such as stainless steel. While Cobalt offers some advantages it is more brittle, making it a poor choice for use in hand-held drill motors where it is prone to breakage. Most of the benefits of Cobalt can be met using a quality HSS bit along with a cutting oil, at much less cost per bit.
FINISHES AND COATINGS
Black & Gold: The Black & Gold Oxide finish increases lubricity to reduce turning resistance and extend tool life.
Black Oxide: The Black Oxide finish resists corrosion and is commonly seen in bits meant for use with ferrous metals.
Bright Finish: An uncoated but polished surface commonly seen in bits used for drilling softer materials
Gold Oxide: Similar to the Black & Gold finish, Gold Oxide increases lubricity and extends tool life.
TIN: An abbreviation for Titanium Nitride. TIN is a gold colored ceramic finish applied to a HSS bit to help the bit keep its edge sharper for longer and to extend bit life. TIN reduces friction allowing for deeper drilling in hard materials and for faster drilling speeds.