411 REFERENCE · Wiktionary
3H
Reference material by Wiktionary contributors. This retains its source identity and is not 411 news reporting.
English
Noun
- s
en British English A grade of pencil with lead that makes lighter marks than a pencil grade 2H but darker marks than a pencil of grade 4H; a pencil with hard lead.
A pencil of grade 3H.
tritium. In this case, the "3" should be superscripted: 3H.
en Tritium