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    58 Products
    About Drill Bits
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    Compare material, finish, length class, and decimal size equivalents.

    Left-Hand Cobalt Steel Drill Bits

    The flutes spiral in the opposite direction of other bits and stay sharp longer than high-speed steel. They’re primarily used to remove stripped screws. Choose a bit that’s slightly smaller than the diameter of the screw’s head. Set your power tool to rotate in reverse. Slowly drill in the center of the screw head, maintaining constant pressure. As the bit penetrates, it will catch onto the screw and reverse it out of the hole. If the screw is badly stripped, you might need to punch a starter hole. Also known as reverse-flute bits.
    Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.
    Maintenance Length—Shorter than jobbers' length, these bits are more rigid for less wobble when drilling hard material. Also known as mechanics’ bits.
    Titanium Nitride (TiN) Coated—Drill at higher speeds and last longer than uncoated and oxide-coated bits, especially on tough materials like hardened steel and nickel.
    Titanium Aluminum Nitride (TiAlN) Coated—The hardest and most wear-resistant coating, especially at high temperatures. These bits are best for hard and abrasive materials, such as iron, titanium, and fiberglass.
    Uncoated—Polished to eject chips, these are also known as bright finish bits.
    Shank
    Drill Bit
    Size
    Decimal Size
    Equiv.
    Overall
    Lg.
    Max. Drilling
    Dp.
    Type
    Size
    Drill Bit
    Point Type
    Each
    Jobbers' Length
    Image of Product. Side1 orientation. Drill Bits. Left-Hand Cobalt Steel Drill Bits, Jobbers' Length, Round Shank.

    Round Shank

    Image of Specification. Split. Front orientation. Contains Border. Split Point. For Metal.

    Split

     
    Uncoated
    1.5 mm0.0591"
    48 mm22 mmRound
    1.5 mmSplit
    3474A4800000
    2.0 mm0.0787"
    51 mm25 mmRound
    2 mmSplit
    3474A490000
    2.5 mm0.0984"
    60 mm35 mmRound
    2.5 mmSplit
    3474A510000
    3.0 mm0.1181"
    70 mm41 mmRound
    3 mmSplit
    3474A520000
    3.5 mm
    0.1378"
    73 mm45 mmRound
    3.5 mmSplit
    3474A530000
    4.0 mm0.1575"
    83 mm54 mmRound
    4 mmSplit
    3474A5400000
    4.5 mm
    0.1772"
    86 mm56 mmRound
    4.5 mmSplit
    3474A5500000
    5.0 mm0.1968"
    92 mm62 mmRound
    5 mmSplit
    3474A5600000
    5.5 mm
    0.2165"
    95 mm64 mmRound
    5.5 mmSplit
    3474A5700000
    6.0 mm0.2362"
    102 mm70 mmRound
    6 mmSplit
    3474A5800000
    6.5 mm
    0.2559"
    105 mm73 mmRound
    6.5 mmSplit
    3474A5900000
    7.0 mm0.2756"
    105 mm73 mmRound
    7 mmSplit
    3474A6100000
    7.5 mm
    0.2953"
    111 mm78 mmRound
    7.5 mmSplit
    3474A6200000
    8.0 mm0.315"
    114 mm81 mmRound
    8 mmSplit
    3474A6300000
    8.5 mm
    0.3346"
    121 mm87 mmRound
    8.5 mmSplit
    3474A6400000
    9.0 mm0.3543"
    124 mm89 mmRound
    9 mmSplit
    3474A6500000
    9.5 mm
    0.374"
    127 mm92 mmRound
    9.5 mmSplit
    3474A6600000
    10.0 mm0.3937"
    130 mm95 mmRound
    10 mmSplit
    3474A6700000
    10.5 mm
    0.4134"
    133 mm98 mmRound
    10.5 mmSplit
    3474A6800000
    11.0 mm0.4331"
    140 mm103 mmRound
    11 mmSplit
    3474A6900000
    11.5 mm
    0.4528"
    143 mm106 mmRound
    11.5 mmSplit
    3474A7100000
    12.0 mm0.4724"
    149 mm111 mmRound
    12 mmSplit
    3474A7200000
    12.5 mm
    0.4921"
    152 mm114 mmRound
    12.5 mmSplit
    3474A7300000
    13.0 mm0.5118"
    152 mm114 mmRound
    13 mmSplit
    3474A7400000
     
    Maintenance Length
    Image of Product. Side1 orientation. Drill Bits. Left-Hand Cobalt Steel Drill Bits, Maintenance Length, Round Shank.

    Round Shank

    Image of Specification. Split. Front orientation. Contains Border. Split Point. For Metal.

    Split

     
    Titanium Nitride (TiN) Coated
    5/64"
    0.0781"
    2"0.88"Round
    5/64"Split
    3474A280000
    7/64"
    0.1094"
    2 1/4"0.84"Round
    7/64"Split
    3474A290000
    1/8"
    0.125"
    2 1/4"1.06"Round
    1/8"Split
    3474A310000
    5/32"
    0.1563"
    2 5/8"1.27"Round
    5/32"Split
    3474A320000
    3/16"
    0.1875"
    2 7/8"1.34"Round
    3/16"Split
    3474A330000
    7/32"
    0.2188"
    3 1/8"1.42"Round
    7/32"Split
    3474A340000
    1/4"
    0.25"
    3 3/8"1.63"Round
    1/4"Split
    3474A350000
    5/16"
    0.3125"
    3 3/4"1.97"Round
    5/16"Split
    3474A3600000
    3/8"
    0.375"
    4 1/8"2.06"Round
    3/8"Split
    3474A3700000
     
    Titanium Aluminum Nitride (TiAlN) Coated
    5/64"
    0.0781"
    2"0.88"Round
    5/64"Split
    3474A380000
    7/64"
    0.1094"
    2 1/4"0.84"Round
    7/64"Split
    3474A390000
    1/8"
    0.125"
    2 1/4"1.06"Round
    1/8"Split
    3474A410000
    5/32"
    0.1563"
    2 5/8"1.27"Round
    5/32"Split
    3474A420000
    3/16"
    0.1875"
    2 7/8"1.34"Round
    3/16"Split
    3474A430000
    7/32"
    0.2188"
    3 1/4"1.42"Round
    7/32"Split
    3474A4400000
    1/4"
    0.25"
    3 3/8"1.63"Round
    1/4"Split
    3474A4500000
    5/16"
    0.3125"
    3 3/4"1.97"Round
    5/16"Split
    3474A4600000
    3/8"
    0.375"
    4 1/8"2.06"Round
    3/8"Split
    3474A4700000
     
    Uncoated
    5/64"
    0.0781"
    2"0.88"Round
    5/64"Split
    3474A110000
    7/64"
    0.1094"
    2 1/4"0.84"Round
    7/64"Split
    3474A120000
    1/8"
    0.125"
    2 1/4"1.06"Round
    1/8"Split
    3474A130000
    5/32"
    0.1563"
    2 5/8"1.27"Round
    5/32"Split
    3474A140000
    3/16"
    0.1875"
    2 7/8"1.34"Round
    3/16"Split
    3474A150000
    7/32"
    0.2188"
    3 1/8"1.42"Round
    7/32"Split
    3474A160000
    1/4"
    0.25"
    3 3/8"1.63"Round
    1/4"Split
    3474A170000
    9/32"
    0.2813"
    3 5/8"1.7"Round
    9/32"Split
    3474A180000
    19/64"
    0.2969"
    3 5/8"1.87"Round
    19/64"Split
    3474A1900000
    5/16"
    0.3125"
    3 3/4"1.97"Round
    5/16"Split
    3474A2100000
    11/32"
    0.3438"
    4"1.98"Round
    11/32"Split
    3474A2200000
    3/8"
    0.375"
    4 1/8"2.06"Round
    3/8"Split
    3474A2300000
    13/32"
    0.4063"
    4 3/8"2.14"Round
    13/32"Split
    3474A2400000
    7/16"
    0.4375"
    4 5/8"2.22"Round
    7/16"Split
    3474A2500000
    15/32"
    0.4688"
    4 3/4"2.23"Round
    15/32"Split
    3474A2600000
    1/2"
    0.5"
    5"2.31"Round
    1/2"Split
    3474A2700000
     
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