Roller Mark?

[JVC]

I have noticed that some morgan dollars have marks on the cheek of Miss Liberty. Is this a roller mark on this 1885 S morgan?

 

[James_OldeTowne]

Yep, classic roller marks on an issue known for them.

[RWB]

Please define "roller mark."

[JVC]

Thanks for the confirmation. These marks appear often for this date even in ms 65 and 66 grades.

[JVC]

It is my understanding that roller marks are created during the minting process. In preparation for creating coin blanks for stamping each coin, metal ignot is pulled between rollers to create planchets of the desired thickness. Debris builds up on the rollers and carves grooves or lines in the planchets. When the coin is struck many of these lines are eliminated by the devices rising from the planchet during striking. If the force of the srike is not great enough then the lines remain on the coin.

[RWB]

On your Morgan dollar, are the marks incuse or raised? Under magnification, what do the marks look like - sharp, soft-edged, shallow, deep, etc.?

[johnny9434]

welcome to the forums as well jvc. hae fun

[James_OldeTowne]

Please define "roller mark."

 

 

 

 

[WoodenJefferson]

[RWB]

...I'm skeptical about the breakdown rolls or drawbench being responsible for "roller marks." Hence the questions about their appearance.

[fishfinder]

Roller marks; straight, long, parallel, shallow, fine, little to no depth variation, can run under devices on fields, more common on devices with large coins, edges?? (I would think they would be on the sharp side and would be related to the offending grit that caused them).

 

Adjustment marks; vary in depth, shorter, haphazard, multi directional, before 1840.

 

Cleaning marks; shorter, may not be parallel, not perfectly straight, post mint.

 

Just my take.

I would like to hear about your skepticism RWB.

[Buffalo Head]

Roller marks; straight, long, parallel, shallow, fine, little to no depth variation, can run under devices on fields, more common on devices with large coins, edges?? (I would think they would be on the sharp side and would be related to the offending grit that caused them).

 

Adjustment marks; vary in depth, shorter, haphazard, multi directional, before 1840.

 

Cleaning marks; shorter, may not be parallel, not perfectly straight, post mint.

 

Just my take.

I would like to hear about your skepticism RWB.

 

 

 

Agreed. Just the same way I look at it, and your discription is very well put!....Joe

[Buffalo Head]

I'm pretty sure these are roller marks if this will help in any way....Joe

 

 

These are adjustment marks.....Ya need to roll in to see them....

 

[RWB]

Anyone have detailed images or descriptions?

 

Will explain skepticism once I have more info on the appearance and micro structure of these critters.

 

{Is that your gold? Nice!}

[BillJones]

The two coins that Buffalo Head posted clearly show the effects of roller or drawing bench lines. Let's put this way. Those lines were clearly on the planchet before the coin was struck, and the dies did not fill enough to obliterate them. They are not from the reeded edge of another coin scraping against the face of the piece because they are simply too long and straight.

 

One coin which almost always shows pre-strike marks on the planchet is the 1926 Philadelphia Sesquicentennial half dollar. That coin often shows pock marks on Washington’s cheek that were planchet marks. The trouble was the dies that struck that coin were so shallow that they not could remove the tiny planchet imperfections.

 

[JVC]

On some dates of Morgan Dollars these roller marks appear time and time again at or near the same spot of the cheek of Ms. Liberty. 1885 and 1887 S Morgan dollars exhibit this trait.

[fishfinder]

Here is a well known so called "finest known" Morgan with roller marks on the cheek.

PCGS 1880-S MS69 PL (Heritage photo).

[C.I.]

Roller marks (I call planchet striations) are more common than one might think. Here are a few 84's but I have them in other years as well.

 

Chet

[James_OldeTowne]

...I'm skeptical about the breakdown rolls or drawbench being responsible for "roller marks." Hence the questions about their appearance.

I'm not so sure that the term "roller marks" attempts to convey the process that caused the striations. Rather, as I denoted in my post above, the marks that occur bear a resemblance to what painters call "roller marks".

 

Oddly enough, I just had a couple of rooms painted, which is what has that association fresh in my mind.

[Buffalo Head]

...I'm skeptical about the breakdown rolls or drawbench being responsible for "roller marks." Hence the questions about their appearance.

I'm not so sure that the term "roller marks" attempts to convey the process that caused the striations. Rather, as I denoted in my post above, the marks that occur bear a resemblance to what painters call "roller marks".

 

Oddly enough, I just had a couple of rooms painted, which is what has that association fresh in my mind.

 

I believe the term "roller marks" is from the feed roller that pushes the rather large sheet of silver along it's way when the planchets are punched out I have been a machinist/tool maker all of my life and am very familiar with these processes. I believe the term striations are marks on the planchet that did not strike out such as these roller marks we are looking at here....I could be wrong but this is the way I understand it.....Joe

 

[Keigwin]

There are also reducer roller marks, not just from feeders. Same idea, though.

Lance.

 

[fishfinder]

The way I understood it they are from a sheet of metal being rolled repeatedly in decreasing increments until the proper thickness is obtained. When debris gets on the surface it leaves long scratches. This happens prior to the planchets being cut.

[Keigwin]

The way I understood it they are from a sheet of metal being rolled repeatedly in decreasing increments until the proper thickness is obtained. When debris gets on the surface it leaves long scratches. This happens prior to the planchets being cut.

Exactly. Here's an early example of problems the Mint was having with reducing rollers. Notice the upper areas near the rim.

Lance.

[RWB]

Anyone have detailed images or descriptions?

 

[WoodenJefferson]

roller marks: Term to describe the mostly parallel incuse lines seen on some coins after striking. These were originally thought to be lines resulting from debris "scoring" the metal strips before the blanks were cut. However, new research has pointed to the final step of strip preparation, the draw bar. To reduce the strips to proper thickness, the final step was to pass them through the draw bar. It certainly seems logical that debris in the draw bar may cause these lines, if so, then draw-bar marks or lines would be a more appropriate term.

 

Found that definition ~here~ so, what's a draw bar? Does it roll, stationary? What?

[PerryHall]

roller marks: Term to describe the mostly parallel incuse lines seen on some coins after striking. These were originally thought to be lines resulting from debris "scoring" the metal strips before the blanks were cut. However, new research has pointed to the final step of strip preparation, the draw bar. To reduce the strips to proper thickness, the final step was to pass them through the draw bar. It certainly seems logical that debris in the draw bar may cause these lines, if so, then draw-bar marks or lines would be a more appropriate term.

 

Found that definition ~here~ so, what's a draw bar? Does it roll, stationary? What?

 

The draw bar explanation makes the most sense since any defects on the edges of the opening of the draw bar would leave longitudinal parallel depressions on the surfaces of the strips. I can't see how that would happen with the strip passing through a pair of rollers unless there are are defects on the rollers that continue around the entire circumference of each roller.

[fishfinder]

What information I could find on the drawing bench; it was introduced by Franklin Peale after the late 1830's having observed Europe's designs. After going through the reducing rollers the strips were trimmed and annealed then drawn through two steel cylinders (dies) perpendicular to each other that revolved in opposite directions. I found it interesting that the SF mint had two (and N.O. one) adjustment lathes for silver dollars where planchets were reduced 20 at a time. What held these planchets while being lathed? I also noted that the CC mint utilized guides to keep the strips flat while being rolled. It would seem that these processes along with machinery pushing coins out of collars etc. there could be various causes for the so called " roller mark". Why do the SF an O mint Morgans have these marks on the devices while others (esp. older?) have them in the fields.

[Conder101]

However, new research has pointed to the final step of strip preparation, the draw bar. To reduce the strips to proper thickness, the final step was to pass them through the draw bar. It certainly seems logical that debris in the draw bar may cause these lines, if so, then draw-bar marks or lines would be a more appropriate term.

The problem with this explanation is that similar marks are still seen on coins today and on non-precious metal coins such as cents and five cent pieces (and todays coppernickel clad) which did not use draw bars. Another term for them is planchet striations. They can be seen on both fields and devices but are more common on the devices because the fields of the dies tend to crush them and wipe them out

[PerryHall]

Anyone know how the rollers are made? If they were machined on a lathe, they could have light machining lines around the circumferences of the individual rollers and these machining marks would be transferred to the rolled strips from which the planchets are punched..

[AegisIII]

Another mystery. Planchet striations also appear on Zincolns. Since these are plated after the planchets are punched out, it is perhaps a bit odd that the striations appear. Granted, the plating is thin. But it is something to think about. BTW, is Mike Diamond on these forums?

 

Shown are two Lincolns, struck off-center (and more), showing planchet striations in the unstruck portion, both pre-1982 and post-1982.