noscriptSherwood LETTER I HSS S/S JOBBER DRILL SHR-025-4544J | Cromwell Tools

Sherwood

LETTER I HSS S/S JOBBER DRILL

SKU:

SHR0254544J

MPN:

SHR-025-4544J

£2.39

Ex VAT

£2.87

Inc VAT

OUT OF STOCK

    Product Details

    Letter Sizes Series J100
    General purpose drills for steels, cast steel, grey cast iron, malleable cast iron, nickel brass, aluminium alloy and graphite. Point angle: 118, helix angle: normal, web thickness: standard, relief angle: 8 - 20, tolerance of diameter: h8, tolerance of shank: f11. Manufactured to ANSI B328, BS 328 and DIN 338.


    Number & Letter Gauge Drills
    Gauge drills are still in common use in the U.S. In the past, they were popular elsewhere, but now have been largely discarded in favour of metric sizes. When using a gauge rather than a standard measurement of size the user has to refer to a table of gauge sizes. For example, to drill a hole which is 10 thou (thousandth of an inch = .0010) bigger than a 1/8 inch bolt, the user must first work out that 1/8 inch is
    125 thou, so the hole size needed is 135 thou, and then must look up in a reference book which gauge drill bit is closest to this diameter - a number 29.
    Number gauge sizes are similar or equivalent in some respects to, but different from, American wire gauge.
    Number gauge is usually used from size 80 (the smallest) to size 1 (the largest) followed by letter gauge size A (the smallest) to size Z (the largest). Number gauge is actually defined down to size 97, but these smaller sizes are rarely encountered. It happens that as the technology for making small drill bits and drilling small holes has become more available,
    metric drills have become the norm.
    The gauge-to-diameter conversion does not follow a set formula, but rather was defined as a useful and practical measure. The graph shows how gauge diameters change with gauge. Each step along the horizontal axis is one gauge size.
    The step size between adjacent gauges is smaller for smaller gauges. This is appropriate, because the tolerance of the diameter of drilled holes is closer for smaller drill bits.


    Gauge inch mm
    80 0.014 0.343
    79 0.015 0.368
    78 0.016 0.406
    77 0.018 0.457
    76 0.020 0.508
    75 0.021 0.533
    74 0.023 0.572
    73 0.024 0.610
    72 0.025 0.635
    71 0.026 0.660
    70 0.028 0.711
    69 0.029 0.742
    68 0.031 0.787
    67 0.032 0.813
    66 0.033 0.838
    65 0.035 0.889
    64 0.036 0.914
    63 0.037 0.940
    62 0.038 0.965
    61 0.039 0.991
    60 0.040 1.016
    59 0.041 1.041
    58 0.042 1.067
    57 0.043 1.092
    56 0.046 1.181
    55 0.052 1.321
    54 0.055 1.397
    53 0.059 1.511
    52 0.064 1.613
    51 0.067 1.702
    50 0.070 1.778
    49 0.073 1.854
    48 0.076 1.930
    47 0.079 1.994
    46 0.081 2.057
    45 0.082 2.083
    44 0.086 2.184
    43 0.089 2.261
    42 0.094 2.375
    41 0.096 2.438
    40 0.098 2.489
    39 0.099 2.527
    38 0.101 2.578
    37 0.104 2.642
    36 0.106 2.705
    35 0.110 2.794
    34 0.111 2.819
    33 0.113 2.870
    32 0.116 2.946
    31 0.120 3.048
    30 0.129 3.264
    29 0.136 3.454
    28 0.141 3.569
    27 0.144 3.658
    26 0.147 3.734
    25 0.149 3.797
    24 0.152 3.861
    23 0.154 3.912
    22 0.157 3.988
    21 0.159 4.039
    20 0.161 4.089
    19 0.166 4.216
    18 0.169 4.305
    17 0.173 4.394
    16 0.177 4.496
    15 0.180 4.572
    14 0.182 4.623
    13 0.185 4.699
    12 0.189 4.801
    11 0.191 4.851
    10 0.194 4.915
    9 0.196 4.978
    8 0.199 5.055
    7 0.201 5.105
    6 0.204 5.182
    5 0.206 5.220
    4 0.209 5.309
    3 0.213 5.410
    2 0.221 5.613
    1 0.228 5.791


    A	0.234	5.944
    B 0.238 6.045
    C 0.242 6.147
    D 0.246 6.248
    E 0.250 6.350
    F 0.257 6.528
    G 0.261 6.629
    H 0.266 6.756
    I 0.272 6.909
    J 0.277 7.036
    K 0.281 7.137
    L 0.290 7.366
    M 0.295 7.493
    N 0.302 7.671
    O 0.316 8.026
    P 0.323 8.204
    Q 0.332 8.433
    R 0.339 8.611
    S 0.348 8.839
    T 0.358 9.093
    U 0.368 9.347
    V 0.377 9.576
    W 0.386 9.804
    X 0.397 10.08
    Y 0.404 10.26
    Z 0.413 10.49

    Product Specification
    Attribute
    Value

    Brand

    Sherwood

    Coolant Delivery

    External

    Cutting Direction

    Right Hand

    Drill Diameter Letter

    I

    Drill Diameter Tolerance

    h8

    ECLASS Code

    21010101

    Finish/Coating

    Black Oxide

    Flute Construction

    Ground Flute

    Flute Length

    69mm

    Flute Type

    Spiral

    Helix Type

    Normal Helix

    Individual or Set

    Individual

    Material

    High Speed Steel

    Number of Flutes

    2

    Overall Length

    109mm

    Point Angle

    118°

    Point Type

    Split Point

    Shank Diameter Tolerance

    f11

    Standards Met

    ANSI B328 BS 328 DIN 338

    UNSPSC Code

    23241634

    Web Thickness

    Standard