TOOLTALK Drill Bits Drill Bit Length 1. S crew Machine/Stub Length Short, sturdy drills used in very tight spaces with extra strength requirements. 1 4 2. M echanic Length Shorter than jobber drills and used in tight spaces. Typically have flattened shanks to prevent slippage in a drill chuck. 3. J obber Length Most common drill length. 2 5 4. S ilver & Deming/Reduced Shank For use when the drill diameter exceeds the drill chuck diameter. 3 5. L ongboy/Extra Length Used for deep holes and has a long reach. Drill Points Flatter points have better cutting action. Steeper points create torque. 118° - All-purpose drill for soft metal, wood and plastic. 135° Split Point – Self-centering drill for most metals. Other points include: 118° Split Point, 130°, 135°, 140°, and 150° Drill Bit Angles ‘Explained’ 118° 135° Straight Shank Drills Standard Flute – Most common. Capable of cutting a depth 4x the diameter. Most effective in light duty applications. Fast Spiral Drills – Ideal for medium and deep hole drilling of low strength materials like: brass, bronze and aluminum. Parabolic Drills – For deep hole drilling. Ideal for low to medium strength materials. Capable of drilling a depth 10x the diameter. Slow Spiral Drills – Used for long, chipping materials like aluminum and copper. Half Round Drills – Used for deep hole drilling for very soft materials like rubber and brass. Reduced Shank Drills Popular choice for maintenance and repair due to shank size being smaller than drill diameter. Can drill larger holes than standard drill chuck capacity. 3/8" Reduced Shank – Drills holes up to 1/2" width, 3/8" drill chuck. 1/2" Reduced Shank (Silver & Deming) – Drills holes up to 1-1/2" width, 1/2" drill chuck. 3/4" Reduced Shank – Drills holes up to 2" with 3/4" drill chuck. Looking for Metalworking Tools? Contact Fastenal at 844.365.8665 or cuttingtoolsupport@fastenal.com Go to www.fastenal.com/metalworking for previous Tool Talks
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