Letter O HSS S/S Jobber Drill

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. Gaugeinch mm 800.0140.343 790.0150.368 780.0160.406 770.0180.457 760.0200.508 750.0210.533 740.0230.572 730.0240.610 720.0250.635 710.0260.660 700.0280.711 690.0290.742 680.0310.787 670.0320.813 660.0330.838 650.0350.889 640.0360.914 630.0370.940 620.0380.965 610.0390.991 600.0401.016 590.0411.041 580.0421.067 570.0431.092 560.0461.181 550.0521.321 540.0551.397 530.0591.511 520.0641.613 510.0671.702 500.0701.778 490.0731.854 480.0761.930 470.0791.994 460.0812.057 450.0822.083 440.0862.184 430.0892.261 420.0942.375 410.0962.438 400.0982.489 390.0992.527 380.1012.578 370.1042.642 360.1062.705 350.1102.794 340.1112.819 330.1132.870 320.1162.946 310.1203.048 300.1293.264 290.1363.454 280.1413.569 270.1443.658 260.1473.734 250.1493.797 240.1523.861 230.1543.912 220.1573.988 210.1594.039 200.1614.089 190.1664.216 180.1694.305 170.1734.394 160.1774.496 150.1804.572 140.1824.623 130.1854.699 120.1894.801 110.1914.851 100.1944.915 90.1964.978 80.1995.055 70.2015.105 60.2045.182 50.2065.220 40.2095.309 30.2135.410 20.2215.613 10.2285.791 A0.2345.944 B0.2386.045 C0.2426.147 D0.2466.248 E0.2506.350 F0.2576.528 G0.2616.629 H0.2666.756 I0.2726.909 J0.2777.036 K0.2817.137 L0.2907.366 M0.2957.493 N0.3027.671 O0.3168.026 P0.3238.204 Q0.3328.433 R0.3398.611 S0.3488.839 T0.3589.093 U0.3689.347 V0.3779.576 W0.3869.804 X0.39710.08 Y0.40410.26 Z0.41310.49

Drill Diameter Tolerance	H8
Flute Length	75mm
Flute Construction	Ground flutes
Number of Flutes	2
Shank Diameter Tolerance	F11
Standards Met	ANSI B328 | BS 328 | DIN 338
Series	J100
Point Angle	118\u00b0
Trade Letter	O
Web Thickness	Standard
Material	HSS
Helix Type	Normal Helix
Drill Diameter Letter	O
Finish/Coating	Black Oxide
Gauge Size	O
Flute Type	Spiral
Coolant Delivery	External
Cutting Direction	Right Hand
Overall Length	117mm
Point Type	Split Point