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<p>[QUOTE=&quot;zumbly, post: 2334686, member: 57495&quot;]I&#039;m not very geeky when it comes to the actual minting process and metallurgy of the coins I collect, but I&#039;m probably like many others in that I get more interested when those aspects produce striking visual results.&nbsp; Flow lines are one of those things, and they can be quite dramatic in appearance, beautiful even.&nbsp; The Lucius Verus below is a recent addition to the collection, and on the obverse you can see long flow lines radiating outwards from the bust, over the legends and towards the edge of the coin.&nbsp; </p><p><br /></p><p>Flow lines seem particularly common on coins from certain periods (Antonine denarii from my own obsveration), and more obvious on the obverse than the reverse.&nbsp; If you have a coin with strong or dramatic flow lines that make you like it more, please let us see it!</p><p><br /></p><p>[ATTACH=full]473680[/ATTACH]</p><p><b>LUCIUS VERUS</b></p><p>AR Denarius</p><p>3.4g, 19mm</p><p>Rome mint, AD 166-167</p><p>RIC III 574</p><p>O: L VERVS AVG ARM – PARTH MAX, laureate head right.</p><p>R: TR P VII – IMP IIII COS III, Victory advancing left, holding up wreath in right hand and palm in left.</p><p><br /></p><p>The writeup below on flow lines is by Barry Murphy, from an old list posting I dug up online.&nbsp; </p><p><br /></p><p>&quot;Flow lines develop in the die, not the flan. When a coin is struck the flan expands from the center towards the edges. Flow lines appear in spots where the devices meet the fields or anywhere where there is a change in depth of the die. As a flan is struck and the metal expands, there is friction and a change of speed in the flow of the metal wherever there is a change in the depth of the die. The most abrupt change occurs where the devices meet the fields, but there are other places such as around the ears and eyes. This friction is what causes the flow line to appear in the die. At first they are microscopic, but with successive strike they grow. There is much less friction across the fields so you are much less likely to get flow lines in the fields, although, as a die is used more and more, the flow lines extending from the devices can extend across the fields. The most likely places for flow lines to develop are around the bust and at the tops of the letters, extending toward the rims, as you go from device to field. </p><p><br /></p><p>&quot;Where and when flow lines develop are a function of several factors. 1) The depth of the engraving. 2) How close the engraving is to the edge of the die. 3) The hardness of the die and the eveness of that hardess across the die&#039;s surface. 4) Whether the flan is struck hot or cold 5) How hard the dies are routinely struck. All these factors effect the speed the metal flows and in which directions it flows the fastest. The flow lines will develop quickest and deepest where the metal flows the fastest and where the dies are the softest.</p><p><br /></p><p>&quot;Even today, modern dies develop flow lines. It is these microscopic lines in the die that give a coin cartwheel luster. Modern dies though are repolished occasionally so the flow lines tend to be erased repeatedly. Ancient dies were not polished as frequently, if at all with most dies, and the flow lines would continue to grow as the die was used. Two coins struck from the same dies in relative proximity to each other should exhibit the same flow lines.&quot;</p><p><br /></p><p>Here&#039;s an enlarged picture of the fields in front of the bust of my coin, with the lines showing up more clearly.&nbsp; </p><p><br /></p><p>[ATTACH=full]473681[/ATTACH][/QUOTE]</p><p><br /></p>

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