| Pennyweight | |
|---|---|
.jpg) 17th-century Irish weight, 8dwt | |
| General information | |
| Unit system | Troy weight |
| Unit of | Mass |
| Symbol | dwt |
| Conversions | |
| 1 dwtin ... | ... is equal to ... |
| Troy | 1⁄240 troy pound |
| Avoirdupois | 48⁄875 oz |
| SI units | 1.55517384 g |
Apennyweight (dwt) is a unit ofmass equal to 24 grains,1⁄20 of atroy ounce,1⁄240 of atroy pound,48⁄875avoirdupois ounce[1] and exactly 1.55517384 grams.[2] It is abbreviateddwt,d standing fordenarius – (an ancient Roman coin), and later used as the symbol of an oldBritish penny (see£sd).
In the Middle Ages, anEnglish penny's weight was literally, as well as monetarily,1⁄20 of an ounce and1⁄240 of a pound ofsterling silver. At that time, the pound unit in use in England was theTower pound, equal to 7,680 Tower grains (also known as wheat grains). The medieval English pennyweight was thus equal to 32 Tower grains. When Troy weights replaced Tower weights in 1527, the Troy weights were defined in such a way that the old Tower pound came out to exactly 5,400 Troy grains (also known as barleycorns), the Tower pennyweight22+1⁄2 Troy grains (and thus approximately 1.46 grams). After 1527, the English pennyweight was the Troy pennyweight.[3] 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, were1⁄15 or 6.667% more than the Tower equivalents.
The troy pound and the pennyweight lost their official status in theUnited Kingdom in theWeights and Measures Act of 1878; only the troy ounce and its decimal subdivisions remained official. The troy ounce enjoys a specific legal exemption frommetrication in the UK.[4]
The pennyweight is the common weight used in the valuation and measurement of precious metals. Jewellers use the pennyweight in calculating the amount and cost of precious metals used in fabricating or casting jewellery. Similarly, dentists and dental labs still use the pennyweight as the measure of precious metals in dental crowns and inlays.[5]
Pennyweight and grains are still used to weighgooseberries in competitions inCheshire, northwest UK. Over thePennines inYorkshire the alternativedrams and grains measurement has been used since a new set of scales was purchased by the Egton Bridge Old Gooseberry Society in 1937. As of 2018, the world record for the heaviest gooseberry of41 dwt 11 gr (64.5 g) was held by Kelvin Archer of Cheshire.[6]
The most common abbreviation for pennyweight isdwt;d, for the Romandenarius, was the abbreviation forpenny beforeDecimalisation of the British monetary system. Alternate abbreviations arepwt andPW.
Although the abbreviations are the same, the pennyweight bears no relation to the weight of the Americanpenny nail. That name is derived from the price for a hundred nails in 15th centuryEngland: the larger the nail, the higher the cost per hundred.[7][8][9][10]The pennyweight also bears no relation to the weight of the American "penny" (1 cent) coin, which weighs 2.5 g (for those minted after 1982).[11]
| 1 pennyweight | = 24 grains |
| =1⁄20 Troy ounce | |
| =1⁄240 Troy pound | |
| =1.55517384 grams |
pennyweight.
Part II Weighing and Measuring for Trade ... 8 Units of measurement, weights and measures lawful for use for trade ... (2) No person shall use for trade—(a) the ounce troy, except for the purposes of transactions in, or in articles made from, gold, silver or other precious metals, including transactions in gold or silver thread, lace or fringe...
This section is for those in the trade. Those in the trade include jewellers, dentists and dental laboratories who have a store front, State ID numbers and Federal ID numbers ... We do not list a dental estimating factor as there is no standard gold percentage for dental solids
Applied to nails, such adjectives denote the original price (in 15th c.) per hundred; as fivepenny nail, a nail which cost 5d. a hundred, tenpenny nail, a nail costing 10d. a hundred. (These names persisted after the prices fell, as they began to do in some places before 1500, and they were eventually used to designate sizes of nails.)[permanent dead link]
{{cite book}}: CS1 maint: postscript (link)The following table gives specifications for The United States Mint legal tender coins presently in circulation