The Peg-Leg

Working hub and working die polishings and treatments
October 8, 2010

High relief Proof Hub and Die Abradings and Polishings

By Thomas Kalantzis

Early on in the hubbing processes, the mint found it necessary to change the relief of some high relief working hubs so that the working die produced from the hub could with-stand the strikes and or striking pressure, at the working hub level because of striking issues they had on the die ( the working die broke up early and as a result the costs would go up and put them behind in production ) the mint abraded the hub then made the die, the die then is finely polished cleaning up the field so it did not look abraded, my thinking at this time is, had the relief not been addressed at the hub level, the working die would not last long and would begin to break up much sooner then intended, and is one reason we see many coins with what is known as a peg-leg for 1971 s proof, the are in liberty missing the lower serif on the bottom of the leg of the are of proof coins, I have added pictures to show both hub and die abrasion and die abrasions.

On the hub the details are raised and rounded high relief, a coin looks like the hub, numbers and lettering and head and bust come out at you, on dies the head and bust as well as the letters and numbers are incuse.
All working hubs were made with a full are first, as the working dies started cracking up, the mint realized they had a big problem in that the relief was causing the dies to crack up prematurely so as a temporary fix to abrade the working hubs ( the are in liberty and the Liberty area seemed to be most affected ) then remade working dies with the same working hub but this time the are in liberty is a peg-leg and much lower to the field, then a die made from that same hub would need the field ( die ) polished to cover up what was done on the hub level, polishings to the die bring the field and a letter or number apart from each other as well as thinning of the letters.

The 1972 proof peg legs are more then likely from a reserved hub made in 1971 after the fix to be used for 1972 and is why they are peg-leg also but look somewhat different then the 1971 peg-legs looked, the 1972 has a rounder peg-leg, these peg-legs were hubbed not abraded at the working hub level, different looking.

The low relief working die was abraded, not for the same reason however abrading the die can bring the field and a letter or other digits a part from each other, but rather to remove clash marks and any other mint errors introduced to the working die via the process, by abrading a BS working die then a polishing to remove the scaring that effects the die when it is abraded on none proof die, at the die level you can polish the abraded area but still will see there work in the form of rough surface under high magnification 200x, Raised area or raised scares that happens when abrading a none proof die as apposed to the high relief proof dies that were polished smooth with different scaring at 200x, looks more like tiny struck-through fragments but yet smooth do to die polishing.

When abrading high relief dies a finer treatment was needed, to remove any issues brought on from the hub abrading s, on the working dies, the working die would go through a very fine treatment of polishings and treatment's to cover up there errors, sometimes the eye area we see polishings and removal of parts of the eye area, also the the liberty area ( are ) and also the E of WE and on some the date digits, they have become artists at the mint being able to remove detail, on the hub side for instance the last number in the date was not added to an undetermined number of hubs, early on this was done so the mint could just add the last number as apposed to the whole date, as we have seen on some die representatives with that same doubling pattern, found from mint to mint, also year to year, as time goes on more representatives will be found.

The Proof and Business struck coins from the San Francisco mint, because were sold for more money for there 40% silver content had seen far less Clash dies ( Better quality control and top of the line press ) then other mints and as a result few die representatives are known and considered rare by many, one die that comes to mind is the one peg-leg 40% silver business strike that had issues and received polishings to the working dies produced by one or a few working hubs, from one working die to the next working die made from that same working hub we see degrees of polishings to each of the working dies.

My thinking at this point is for high relief proof, first the hub was abraded for relief and metal flow reasons, all to do with extending die life, anything done by hand may and did in many cases have caused issues on the field so when the die was made the field would have had to be polished, so my feeling is to make the are in liberty have a peg-leg both the hub and the die respectively would have been worked on each in there own way, the hub to relieve the relief to extend the life of the die, and the die to cover up any introduced damage done on the hub.

In conclusion I found this abrading-polishing-retreating on the hubs and die's in the minting process important, we need to be able to understand what was done and why, the effect of what was done, what it means to be abrade and polish at the hub level and the die level, and why.
All of the above is still going through learning pains, as research continues we will learn more.

Every day we learn a bit more that helps us better understand.

Posted by Thomas Kalantzis. Posted In : Working hub and Working die