Predecimal Threepence Diameter1834 – 1944: 16mm1937 – 1967: 22mm Weight1834 – 1944: 1.41g1937 – 1967: 6.80g Composition1834 – 1920: 0.9250 silver1921 – 1944: 0.500 silver1937 – 1967: nickel-brass Click here to download the QR code for this page