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Reading the spec sheet
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The chart calls for 59/64". The values below are direct conversions of the stored NPT tap-drill row.
Compare 3/4-14 with every other NPT entry in the same source table. The current answer is highlighted.
| Thread | Tap drill | Decimal inches | Millimeters |
|---|---|---|---|
| 1/8-27 NPT | R | 0.339″ | 8.61 mm |
| 1/4-18 NPT | 7/16" | 0.4375″ | 11.11 mm |
| 3/8-18 NPT | 37/64" | 0.578″ | 14.68 mm |
| 1/2-14 NPT | 23/32" | 0.719″ | 18.26 mm |
| 3/4-14 NPTCurrent | 59/64" | 0.922″ | 23.42 mm |
The existing tap-drill lookup is preset to 3/4-14 NPT. Search any thread in the source chart without leaving this page.
Use 59/64". Its decimal diameter is 0.922 inch, or 23.42 mm.
59/64" converts to 23.42 mm. The listed chart designation remains the recommended drill selection for this thread.
Yes. This chart row is in the NPT family, and the comparison table on this page contains only other NPT entries from the same shop chart.
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