Pennyweight Troy weights were defined in such a way that the old Tower pound came out to exactly 5400 Troy grains (also known as barleycorns), the Tower pennyweight Troy grains (and thus approximately 1.46 grams). After 1527, the English pennyweight was the Troy pennyweight. of 24 Troy grains. Thus the Troy pound, ounce, and pennyweight, with their definitions given in terms of the Troy grain instead of in terms of the Tower grain, were 1/15 or 6.667% more than the Tower equivalents. The Troy pound and the pennyweight lost their official status in the United Kingdom in the Weights and Measures
Great Recoinage of 1816 shillings weighing 87.2727 grains (or 5.655 grams), half-crowns of 218.1818 grains (14.138 grams) and crowns of 436.3636 grains (28.276 grams). Over the many reigns until decimalisation other denominations came and went, such as the threepence, sixpence, florin, and double florin, always weighing exactly one troy pound per 66 shillings (irrespective of fineness, which was reduced to 50% in 1920, and to 0% in 1947). This made 5 sterling silver shillings (which is 1 crown), about the weight of .9091 troy ounce of sterling silver. Great Recoinage of 1816 The Great Recoinage of 1816 was an attempt by the British Government