Are these "Lathe-Lines" on this medal??

keets

I was looking at some archived medals this morning trying to sort out some planchet type questions and ran across an 1870 Pilgrim HK-13 which I had never seen before. The medal is quite striking in appearance but what really caught my attention are the circular lines which are clearly visible on the reverse of the medal. I've included a link to the NGC cert page to allow viewing the medal in the holder, but it doesn't appear that the lines are on the plastic. I've seen this before and have a few medals with the same appearance, raised circular lines that are part of the design and flow uniterrupted over the other design elements/lettering. If you can offer a good description of how/why this sometimes occurs, please do. Post an image if you have one.

Thanks in advance.

Al H.

NGC cert page link --- https://ngccoin.com/certlookup/3740160-013/67/

dcarr

It is possible that they are lathe lines.
It is also possible that they are due to some imperfection in the rolled steel rod that would have been cut to length and then lathed again to make the individual die blank.
Or it could be some concentric rings on the planchet that was struck.

Do other examples of this same medal (from the same die) also have the rings ?

davewesen

those perfect circles were made by a lathe, the question is when

on stock before die was made or on punch used to make blanks

you might be able to determine if the rings are above or below the surface, but does it matter?

moursund

Whoever made that was too lathey to polish those away...

bsshog40

I'm wondering if it's not part of the design. I don't see any lathe lines on the reverse. Plus the lines go over the book which would be hard to lathe over an edge like that without jumping.

keets

after the die blanks are turned I'd expect that at least the working end would be ground flat.

a question to Dan --- I purchased two of your Panama Canal medals and they have these lathe lines on them, I'm sure you're aware of that. what was your process in making those medals which resulted in the lines?? it seems that would answer the question of when/how they developed on this medal since the process(s) are probably similar.

keets

I'm wondering if it's not part of the design. I don't see any lathe lines on the reverse. Plus the lines go over the book which would be hard to lathe over an edge like that without jumping.

I've viewed/owned enough of these to say it is not part of the design, and yes, if you look closely they are present on both obv/rev.

ctf_error_coins

Looks like it to me.

Here is mine for comparison ...

BuffaloIronTail

@moursund said:
Whoever made that was too lathey to polish those away...

OH BROTHER!

Pete

moursund

@BuffaloIronTail said:

@moursund said:
Whoever made that was too lathey to polish those away...

OH BROTHER!

Pete

Thank you, thank you! I'll be here all week!

dcarr

@keets said:
after the die blanks are turned I'd expect that at least the working end would be ground flat.

a question to Dan --- I purchased two of your Panama Canal medals and they have these lathe lines on them, I'm sure you're aware of that. what was your process in making those medals which resulted in the lines?? it seems that would answer the question of when/how they developed on this medal since the process(s) are probably similar.

Those would have been caused during the engraving of the dies. The engraving starts in the center and spirals outward. Very small vertical positioning errors can cause the appearance of concentric circles. The circles are typically very narrow and shallow ridges or grooves.

cmerlo1

I wish I'd kept this 1866 Shield Nickel. The lathe lines through the stars and rays from 8:00 to 3:00 are a design improvement, I think

MsMorrisine

the commonly referred to lathe lines are on the die.

the end of the blank die is machined to a conical shape, and not flat. that conical shape is pressed into the hub.

the conical end should be polished to remove the lathe lines.

if there are other sources of lathe lines, then someone else would have to explain it.

keets

moursund

@MsMorrisine said:
the commonly referred to lathe lines are on the die.

the end of the blank die is machined to a conical shape, and not flat. that conical shape is pressed into the hub.

the conical end should be polished to remove the lathe lines.

if there are other sources of lathe lines, then someone else would have to explain it.

Thanks for the explanation. Better lathe than never...

jesbroken

@bsshog40 said:
I'm wondering if it's not part of the design. I don't see any lathe lines on the reverse. Plus the lines go over the book which would be hard to lathe over an edge like that without jumping.

I have seen several others without the concentric lines, Bobby.
Jim

ricko

I have always referred to them as lathe lines.... right or wrong term, it has been commonly applied to this feature for as long as I can remember. Cheers, RickO

Zoins

@MsMorrisine said:
the commonly referred to lathe lines are on the die.

the end of the blank die is machined to a conical shape, and not flat. that conical shape is pressed into the hub.

the conical end should be polished to remove the lathe lines.

if there are other sources of lathe lines, then someone else would have to explain it.

I know the US Mint creates this this way today, but were dies created this way in 1870, per the medal in the OP?

Zoins

@dcarr said:
Do other examples of this same medal (from the same die) also have the rings ?

Here are 3 of mine, none of them have pronounced rings from the photos, but second one has some faint lines over the Bible. The first two are silver plated and the 3rd one is gilt.

crazyhounddog

I’ve been a machinist all my life. So, with that said I find it difficult to believe someone was parting off slugs all day to be struck? I have always been under the impression that they, the mint, punched out the disks. It would be VERY time consuming to part each one off on a lathe. Punching goes fast from a rolled sheet. The lathe lines I believe come from the die itself.

BuffaloIronTail

Lathe Lines on a 1935-P Buffalo Nickel.

Pete

keets

Punching goes fast from a rolled sheet. The lathe lines I believe come from the die itself.

I don't know that anyone has suggested that the planchets were cut individually from a bar, I know I didn't. the "lathe lines" as I've always understood them to be called(see RickO's post above) are transferred to the planchet when it's struck. with that said, I wasn't trying to find out how they got there, only if others agreed that's what they are along with posting examples they own.

apparently they aren't as uncommon as I assumed.

keets

below is a link which includes images of the "lathe lines" on a finished die which weren't polished off.

https://cointalk.com/threads/what-lathe-lines-look-like-on-a-die.200381/

MsMorrisine

I have a few well circulated Kennedy with lathe lines tucked away

Type2

I don’t know but it is a nice one.👍

MsMorrisine

https://forums.collectors.com/discussion/comment/9442575/#Comment_9442575

Goldminers

There are similar circular lines on this US Philadelphia Mint medal from 1960. They are easily seen in the fields, but they are also on the horse in several locations.

moursund

The US mint used to use a lathe to produce those concentric rings. Now I think they use lather-beams. 😏

leothelyon

Here's a 1938 movie/video on how coins are made. At the 2:13 mark, you'll see how those "lathe lines are made. Don't be afraid to click on the link. Several of my JN's have lathe lines, a clear indicator of an EDS strike.
https://www.bing.com/videos/search?q=how+coins+are+made&&view=detail&mid=4DBC86B1D5C99F8470A84DBC86B1D5C99F8470A8&rvsmid=9DBF4FB84F1CE988510B9DBF4FB84F1CE988510B&FORM=VDQVAP

Leo

Broadstruck

Yes lathe lines.

I like them as they are only seen on very early strikes