Basics of Drill Bits

Straight shank drills are the most common style in the world. Shank size always matches the cutting diameter.

• Twist drill bits are the most widely used drill style globally, suitable for a broad range of applications in both ferrous and non-ferrous materials.

• Parabolic drill bits are designed for deep-hole drilling, minimizing the need for pecking cycles.

• Slow spiral drill bits are ideal for long-chipping materials, such as aluminum and copper, providing improved chip control.

• Fast spiral drill bits are well-suited for short-chipping materials, such as stainless steel, which enhances chip evacuation and reduces heat buildup.

• Half-round drill bits are used for deep-hole drilling of very soft materials, like brass and rubber.

• Straight flute drill bits are designed for drilling extremely hard steels, offering maximum rigidity and strength.

• Core drill bits are used to enlarge or rework existing holes with improved accuracy and finish.

Reduced shank drill bits are commonly used in maintenance and repair applications. Their smaller shank diameter allows them to drill holes larger than the capacity of standard drill chucks.

• A 3/8" reduced shank drill bit can drill holes up to 1/2" in diameter using a standard 3/8" chuck.

• Silver and Deming drills (with a 1/2" reduced shank) can drill holes up to 1-1/2" in diameter using a standard 1/2" drill chuck.

• A 3/4" reduced shank drill can create holes up to 2" in diameter using a standard 3/4" drill chuck.

Taper shank drill bits are long-length drills designed with a Morse Taper shank, made specifically for spindles that accommodate Morse Taper tooling.

• Taper shank drill bits are available in a variety of styles, including stub length, extra-long, core drills, high-helix, slow-helix, and coolant-fed designs.

• General-purpose drill bits are ideal for maintenance, repair, or short production runs in soft ferrous and non-ferrous materials (see Drill Selection Chart on pages 2–3).

• Heavy-duty drill bits feature a split point to reduce walking and reinforced flutes for enhanced rigidity, making them ideal for drilling harder materials.

• High-performance drill bits are engineered for application-specific operations where productivity and cost per hole are critical. To maximize speed and feed rates, always consult the manufacturer's recommended guidelines.

• Screw Machine - Stub length

• Jobber - Standard length

• Taper - Long length

• Extra Length

• Offers a balance of tool life, productivity, and cost-efficiency.

• Performs well in free-cutting and carbon steels, as well as soft non-ferrous materials such as aluminum, brass, bronze, and copper.

• With the proper point angle and helix, cobalt drills offer the most cost-effective solution for machining cast iron, heat-treated steels, and titanium alloys.

• Capable of performing reliably in less-than-ideal setups.

• Provides better wear resistance, higher hardness, and toughness than HSS.

• Resists chipping and microchipping under severe cutting conditions, enabling up to 10% higher speeds compared to HSS.

• Available in complete sets for convenience and versatility.

• Powdered metal offers a cost-effective alternative to solid carbide, providing greater toughness and reduced risk of breakage.

• Tools perform effectively in materials under 30 HRC, including highly abrasive ones like high-silicon aluminums.

• For high-performance applications, carbide drills offer faster speeds, superior heat resistance, and excellent wear durability.

• Offers greater rigidity than HSS, resulting in improved dimensional accuracy and often eliminating the need for reaming.

• Carbide is brittle and prone to chipping under less-than-ideal conditions; heavy feed rates are better suited for HSS and cobalt tools.

• Carbide is commonly used to machine abrasive or difficult materials such as cast iron, non-ferrous alloys, glass, plastics, and composites.

• Carbide-tipped tooling offers many of the advantages of solid carbide tooling at a reduced cost, especially for larger diameter tools.

• Retains lubricants to aid in wear resistance and chip flow.

• Not to be used in non-ferrous materials.

• Polished drill bits do not have a coating, which helps increase chip flow in soft materials.

• For use in aluminum, wood, and plastics.

• Multi-purpose coating that increases tool life and performance.

• Hardness and heat resistance enable operation at speeds and feeds approximately 25–30% higher than uncoated tools.

• Harder and more wear-resistant in moderate temperatures.

• TiCN enables higher spindle speeds, particularly when machining stainless steel, cast iron, and aluminum.

• Requires an increase of 35% to 50% in machining speeds.

• For high temperature and/or abrasive conditions.

• Recommended for stainless steel, high-alloy carbon steels, nickel-based high-temperature alloys, and titanium alloys. Not suitable for aluminum.

• Requires an increase of 75% to 100% in machining speeds.