Reference charts
Hand-built reference tables for working professionals. Each one covers a single lookup completely, cites its data source, and needs no JavaScript.
- Tap Drill Chart (UNC, UNF & Metric) Recommended tap drill sizes for UNC coarse, UNF fine, and metric coarse threads from #4-40 to 3/4-10 and M1.6 to M16, with the 75% thread rule explained.
- Drill Bit Size Chart Every numbered (#80–#1) and letter (A–Z) drill size in decimal inches and millimeters, plus how the wire-gauge series works.
- Fraction to Decimal to Millimeter Chart Wall-chart style lookup from 1/64 inch to 2 inches: exact decimal inches and exact millimeters for every fraction.
- Sheet Metal Gauge Thickness Chart Gauge to thickness in inches and mm for carbon steel (Manufacturers' Standard Gauge) and aluminum (B&S), and why the same gauge number means different thicknesses.
- AWG Wire Size Chart American Wire Gauge from 4/0 to 40: exact diameter and area from the ASTM formula, copper resistance at 20 °C, and NEC 310.16 ampacities.
- Sandpaper Grit Chart (CAMI vs FEPA) US CAMI grades next to European FEPA P-grades with nominal micron particle sizes, and which grade to reach for at each finishing stage.
- Paper Weight Conversion Chart (GSM ⇄ lb) Convert GSM to basis pounds the right way: why you must know the paper type first, with exact factors for bond, text, cover, index, and tag stocks.
- Camera Sensor Size Chart Active sensor dimensions, area, and crop factor for medium format, full frame, APS-C, Micro Four Thirds, 1-inch type, and phone sensors.
Frequently asked questions
Are these charts printable?
Yes. Every table is plain HTML with no scripts, so it prints cleanly from the browser. Print at 100% scale so millimeter columns stay accurate.
Where do the numbers come from?
Each chart cites its source on the page: standards like ASTM B258 (wire), the Manufacturers' Standard Gauge (sheet steel), FEPA grain sizes (abrasives), or exact arithmetic from defined constants. The site keeps a public sources log.
Why a separate section instead of converters?
Most of these lookups are not conversions between two units you type in; they are fixed tables where you scan a row. A static chart answers faster than a form, and it works when JavaScript does not.