Reference tables for the shop
The numbers, not the fluff.
Size and gauge charts for people who already know what they're looking for. Every value here is calculated from the standard formulas and checked against known reference pairs — so you can verify any row yourself instead of trusting a table someone scraped from somewhere else.
665 rows across 9 charts. Inch and metric on every table. No ads in the middle of the data.
| Chart | What's in it | Rows | |
|---|---|---|---|
| Tap Drill Sizes | UNC, UNF and metric — plus the engagement each real drill actually gives. | 80 | |
| Drill Bit Sizes | Fractional, number, letter and metric in one sorted list, with equivalence groups. | 352 | |
| Thread Sizes | Pitch diameter, minor diameter and tensile stress area from the 60° form. | 80 | |
| Sheet Metal Gauge | Steel, galvanized, stainless and aluminum — four different gauge systems. | 24 | |
| AWG Wire Sizes | Diameter, area, resistance and voltage drop. Computed, not copied. | 44 | |
| Pipe Sizes (NPS) | OD, wall, ID and flow area across Schedule 10 through 160. | 23 | |
| Socket Sizes | Which socket fits which bolt, and which SAE/metric pairs actually substitute. | 31 | |
| Bolt Torque | Computed from proof load, split by dry, plated and lubricated. | 21 | |
| Bulb Socket Sizes | E12 through E40 and the pin bases — the other kind of socket. | 10 |
Why another spec site
Most reference charts online are transcriptions of transcriptions. When a digit gets dropped, it propagates — and nothing on the page tells you where the number came from or how to check it.
Every table here ships with its formula and its verification set. The tap drill chart states the two equations it uses and names the six known thread-to-drill pairs it was checked against. If a value looks wrong, you have everything you need to prove it.
What this site will not do
Some numbers belong to standards bodies that sell them, and copying those tables would be both illegal and a disservice. The wire chart gives diameter, resistance and voltage drop — all computable — but no ampacity values, because those live in NEC Table 310.16 and vary by the code edition your jurisdiction adopted. The site points you at the free official reading room instead of guessing on your behalf.