STS Industrial - Bolts & Screws

 

LEFT HAND HIGH SPEED STEEL DRILL BITS

Left handed 118 degree point drill bits are most commonly used to drill out, and remove broken bolts from tapped holes. Bright finish for added lubricity and resistance to wear.

Left Hand High Speed Steel Drill Bit

  • FRACTIONAL JOBBER LENGTH LEFT HAND BITS:

    Standard length fractional series left hand drill bits. Shank diameter equal to drill diameter.

    Left Hand High Speed Steel Drill Bit

    SIZE

    DECIMAL EQUIVALENT

    FLUTE LENGTH

    OVERALL LENGTH

      1/16 0.0625   7/8 1  7/8
      5/64 0.0781 1 2
      3/32 0.0938 1  1/4 2  1/4
      7/64 0.1094 1  1/2 2  5/8
      1/8 0.1250 1  5/8 2  3/4
      9/64 0.1406 1  3/4 2  7/8
      5/32 0.1563 2 3  1/8
     11/64 0.1719 2  1/8 3  1/4
      3/16 0.1875 2  5/16 3  1/2
     13/64 0.2031 2  7/16 3  5/8
      7/32 0.2188 2  1/2 3  3/4
     15/64 0.2344 2  5/8 3  7/8
      1/4 0.2500 2  3/4 4
     17/64 0.2656 2  7/8 4  1/8
      9/32 0.2813 2 15/16 4  1/4
     19/64 0.2969 3  1/16 4  3/8
      5/16 0.3125 3  3/16 4  1/2
     21/64 0.3281 3  5/16 4  5/8
     11/32 0.3438 3  7/16 4  3/4
     23/64 0.3594 3  1/2 4  7/8
      3/8 0.3750 3  5/8 5
     25/64 0.3906 3  3/4 5  1/8
     13/32 0.4063 3  7/8 5  1/4
     27/64 0.4219 3 15/16 5  3/8
      7/16 0.4375 4  1/16 5  1/2
     29/64 0.4531 4  3/16 5  5/8
     15/32 0.4688 4  5/16 5  3/4
     31/64 0.4844 4  3/8 5  7/8
      1/2 0.5000 4  1/2 6

    All dimensions are in inches.

  • NUMBER SERIES LEFT HAND BITS:

    Standard length drill bits. Number series sizing. Shank diameter equal to drill diameter.

    Left Hand High Speed Steel Drill Bit

    SIZE

    DECIMAL EQUIVALENT

    FLUTE LENGTH

    OVERALL LENGTH

    1 0.2280 2  5/8 3  7/8
    2 0.2210 2  1/2 3  7/8
    3 0.2130 2  1/2 3  3/4
    4 0.2090 2  1/2 3  3/4
    5 0.2055 2  1/2 3  3/4
    6 0.2040 2  1/2 3  3/4
    7 0.2010 2  7/16 3  5/8
    8 0.1990 2  7/16 3  5/8
    9 0.1960 2  7/16 3  5/8
    10 0.1935 2  7/16 3  5/8
    11 0.1910 2  5/16 3  1/2
    12 0.1890 2  5/16 3  1/2
    13 0.1850 2  5/16 3  1/2
    14 0.1820 2  3/16 3  3/8
    15 0.1800 2  3/16 3  3/8
    16 0.1770 2  3/16 3  3/8
    17 0.1730 2  3/16 3  3/8
    18 0.1695 2  1/8 3  1/4
    19 0.1660 2  1/8 3  1/4
    20 0.1610 2  1/8 3  1/4
    21 0.1590 2  1/8 3  1/4
    22 0.1570 2 3  1/8
    23 0.1540 2 3  1/8
    24 0.1520 2 3  1/8
    25 0.1495 1  7/8 3
    26 0.1470 1  7/8 3
    27 0.1440 1  7/8 3
    28 0.1405 1  3/4 2  7/8
    29 0.1360 1  3/4 2  7/8
    30 0.1285 1  5/8 2  3/4
    31 0.1200 1  5/8 2  3/4
    32 0.1160 1  5/8 2  3/4
    33 0.1130 1  1/2 2  5/8
    34 0.1110 1  1/2 2  5/8
    35 0.1100 1  1/2 2  5/8
    36 0.1065 1  7/16 2  1/2
    37 0.1040 1  7/16 2  1/2
    38 0.1015 1  7/16 2  1/2
    39 0.0995 1  3/8 2  3/8
    40 0.0980 1  3/8 2  3/8
    41 0.0960 1  3/8 2  3/8
    42 0.0935 1  1/4 2  1/4
    43 0.0890 1  1/4 2  1/4
    44 0.0860 1  1/8 2  1/8
    45 0.0820 1  1/8 2  1/8
    46 0.0810 1  1/8 2  1/8
    47 0.0785 1 2
    48 0.0760 1 2
    49 0.0730 1 2
    50 0.0700 1 2
    51 0.0670 1 2
    52 0.0635   7/8 1  7/8
    53 0.0595   7/8 1  7/8
    54 0.0550   7/8 1  7/8
    55 0.0520   7/8 1  7/8
    56 0.0465   3/4 1  3/4
    57 0.0430   3/4 1  3/4
    58 0.0420  11/16 1  5/8
    59 0.0410  11/16 1  5/8
    60 0.0400  11/16 1  5/8

    All dimensions are in inches.

    • DRILL SELECTION

      DRILL BIT SELECTION GUIDE:

      Use this chart to help you find the best drill bit for the job. Simply choose your material and then the corresponding tool that best fits your application.

      Drill Bit Selection Guide

    • FEEDS AND SPEEDS

      RECOMMENDED FEED RATES AND SPEED:

      Drill Bit Recommended Feed Rates and Speeds

      Feeds – Feed rates for drilling are governed by the drill diameter, machinability of materials and depth of hole. Speeds – The speed of a drill is determined by the rate which the outer periphery of the tool rotates in relation to material being cut. In general, the SFM at which a drill will operate is within a range based upon the workpiece material, its condition, hardness and depth of hole. It is usually advisable to start the drilling process at a slower SFM and then increase to the maximum.
      RPM = SFM/TD x 3.82 = Revolutions Per Minute
      SFM = RPM x TD x .26 = Surface Feet Per Minute
      TD = Tool diameter in inches

      Drill Bit Feed Rates Technical Data

    • TROUBLESHOOTING

      DRILL TROUBLESHOOTING GUIDE:

      The guide below can help identify the causes of some common issues that can be experienced while drilling.

      Drill Bit Troubleshooting Guide

Sources: Drillco Cutting Tools Product Catalog 2013, Champion Cutting Tools 2011 Product Catalog, Norseman/CTD Product Catalog 2013

Note: All material included on this page is informational only, and should not be used as one’s sole source for design purposes. STS Industrial, Inc. and its affiliates do not guarantee the accuracy of the information on this site, and retain no liability for the use or misuse of the information contained on this site.