quadrans

thumb|–270 BC thumb|Cast coin. Obverse: bust of Hercules l.; three pellets. Reverse: prow of [[galley; three pellets.]] thumb|Teruncius (Apulia, [[Lucera), BC]] thumb|Augustus Quadrans thumb|Quadrans of Domitian The quadrans () or teruncius () was a low-value Roman bronze coin worth one quarter of an as. The quadrans was issued from the beginning of cast bronze coins during the Roman Republic, showing three pellets representing three unciae as a mark of value. The obverse type, after some early variations, featured the bust of Hercules, while the reverse featured the prow of a galley. Coins with the same value were issued from other cities in Central Italy, using a cast process.

After BC, when bronze coinage was reduced to the semuncial standard, the quadrans became the lowest-valued coin in production. Surviving quadrantes from this period (though that name is not shown on the coins) typically have weights between 1.5 grams and 4 grams, perhaps depending in part on the alloy or metals contained. It was produced sporadically until the time of Antoninus Pius (AD 138–161). Unlike other coins during the Roman Empire, the quadrans rarely bore the image of the emperor, due to its small size.