Féadfaidh na toisí seo athrú beagán ag brath ar an ábhar sonrach a úsáidtear, mar shampla cruach dhosmálta nó alúmanam.
Seo é an tábla a thaispeánann an tiús iarbhír de chruach leatháin i milliméadar agus orlach i gcomparáid le méid an tomhsaire:
| Tomhsaire Uimh | orlach | méadrach |
| 1 | 0. 300" | 7.6mm |
| 2 | 0. 276" | 7.0mm |
| 3 | 0. 252" | 6.4mm |
| 4 | 0. 232" | 5.9mm |
| 5 | 0. 212" | 5.4mm |
| 6 | 0. 192" | 4.9mm |
| 7 | 0. 176" | 4.5mm |
| 8 | 0. 160" | 4.1mm |
| 9 | 0. 144" | 3.7mm |
| 10 | 0. 128" | 3.2mm |
| 11 | 0. 116" | 2.9mm |
| 12 | 0. 104" | 2.6mm |
| 13 | 0. 092" | 2.3mm |
| 14 | 0. 080" | 2.0mm |
| 15 | 0. 072" | 1.8mm |
| 16 | 0. 064" | 1.6mm |
| 17 | 0. 056" | 1.4mm |
| 18 | 0. 048" | 1.2mm |
| 19 | 0. 040" | 1.0mm |
| 20 | 0. 036" | 0.9mm |
Am postála: Jul-04-2023