Blue Ribbon™ High Speed Twist Drills
Gauge-Inch-mm Chart
| B&S Gauge |
Millimeter (mm) |
Inch (decimal) |
Inch (fraction) |
|---|---|---|---|
| 1 | 7.348 | 0.289 | — |
| 2 | 6.543 | 0.258 | — |
| — | 6.350 | 0.250 | 1/4 |
| — | 5.953 | 0.234 | 15/64 |
| 3 | 5.827 | 0.229 | — |
| — | 5.556 | 0.219 | 7/32 |
| 4 | 5.189 | 0.204 | — |
| — | 5.154 | 0.203 | 13/64 |
| — | 4.762 | 0.188 | 3/16 |
| 5 | 4.621 | 0.182 | — |
| — | 4.366 | 0.172 | 11/64 |
| 6 | 4.115 | 0.162 | — |
| — | 3.969 | 0.156 | 5/32 |
| 7 | 3.664 | 0.144 | — |
| — | 3.572 | 0.141 | 9/64 |
| 8 | 3.263 | 0.128 | — |
| — | 3.175 | 0.125 | 1/8 |
| 9 | 2.906 | 0.114 | — |
| — | 2.778 | 0.109 | 7/64 |
| 10 | 2.588 | 0.102 | — |
| — | 2.381 | 0.094 | 3/32 |
| 11 | 2.304 | 0.091 | — |
| 12 | 2.052 | 0.081 | — |
| — | 1.984 | 0.078 | 5/64 |
| 13 | 1.828 | 0.072 | — |
| 14 | 1.628 | 0.064 | — |
| — | 1.588 | 0.063 | 1/16 |
| 15 | 1.449 | 0.057 | — |
| 16 | 1.291 | 0.051 | — |
| — | 1.191 | 0.047 | 3/64 |
| 17 | 1.149 | 0.045 | — |
| 18 | 1.024 | 0.040 | — |
| 19 | 0.912 | 0.036 | — |
| 20 | 0.812 | 0.032 | — |
| — | 0.795 | 0.031 | 1/32 |
| 21 | 0.723 | 0.028 | — |
| 22 | 0.644 | 0.025 | — |
| 23 | 0.573 | 0.023 | — |
| 24 | 0.511 | 0.020 | — |
| 25 | 0.455 | 0.018 | — |
| 26 | 0.405 | 0.016 | — |
| — | 0.396 | 0.015 | 1/64 |
| 27 | 0.360 | 0.014 | — |
| 28 | 0.321 | 0.013 | — |
| 29 | 0.286 | 0.011 | — |
| 30 | 0.255 | 0.010 | — |
| 31 | 0.227 | 0.0089 | — |
| 32 | 0.202 | 0.0080 | — |
| 33 | 0.180 | 0.0071 | — |
| 34 | 0.160 | 0.0063 | — |
| 35 | 0.142 | 0.0056 | — |
| 36 | 0.127 | 0.0050 | — |
| 37 | 0.113 | 0.0045 | — |
| 38 | 0.101 | 0.0040 | — |
| 39 | 0.090 | 0.0035 | — |
| 40 | 0.080 | 0.0031 | — |
| B&S Gauge |
Millimeter (mm) |
Inch (decimal) |
Inch (fraction) |
Specifications
| Drill # | Diameter |
|---|---|
| 50 | 0.070″ |
| 51 | 0.067″ |
| 52 | 0.0635″ |
| 53 | 0.0595″ |
| 54 | 0.055″ |
| 55 | 0.052″ |
| 56 | 0.0465″ |
| 57 | 0.043″ |
| 58 | 0.042″ |
| 59 | 0.041″ |
| 60 | 0.040″ |
| 61 | 0.039″ |
| 62 | 0.038″ |
| 63 | 0.037″ |
| 64 | 0.036″ |
| 65 | 0.035″ |
| 66 | 0.033″ |
| 67 | 0.032″ |
| 68 | 0.031″ |
| 69 | 0.0292″ |
| 70 | 0.028″ |
| 71 | 0.026″ |
| 72 | 0.025″ |
| 73 | 0.024″ |
| 74 | 0.0225″ |
| 75 | 0.021″ |
| 76 | 0.020″ |
| 77 | 0.018″ |
| 78 | 0.016″ |
| 79 | 0.0145″ |
| 80 | 0.0135″ |
