Does the mint actively look out for DDOs/DDRs, etc...?

[riff]

do they have someone looking out for these things as they mint coins? and if so, do they "stop the press" when they find one to replace the die? just something i have always wondered.

[Maineman750]

Yes, that is generally what they do.

[trails]

It depends how obvious the DDO / DDR is. The FY 2009 Lincoln cent series is a great example of the mint just letting go with the DDRs and DDOs, even though some of them were very obvious under minimal magnification. However, the Washington D.C. Quarter with very obvious DDR may have had that die pulled and replaced.

[coppercoins]

They don't actually check the coins. The dies are inspected prior to use. They are supposed to be caught before they start minting coins. Once the dies have been hung on the press to mint coins, they are considered checked; the process is not halted to inspect the coins or dies for doubling. The only work stoppage after the dies begin to mint coins is for die damage or wear.

One thing to remember is that the mint creates coins on a mass utility level in the billions of pieces using hundreds of die pairs. They don't care about little doubled eyelids, flyspeck doubled columns and the like. These are considered a tolerable part of the minting process and are allowed to pass through the system without issue.

[Justafarmer]

As Chuck said - once placed in service it is rare a die is pulled from coin production due to design issues. In most cases a woeking die that produces a variety is going to produce approximately the same number of coins as a die that does not exhibit these features.

[Maineman750]

I'm having a tough time believing there is no inspection of coins when you consider the 72 die #4, the 92 CAM's,or any of the rare varieties.

[mustbebob]

There are other reasons why there may be reduced numbers of varieties like the 72 Die-004 and the 92 CAMs. If memory serves me correctly, the 72 die-004 had numerous rim cuds, even in EDS. They could have changed the die early becuase of that. There is also the possibility that it was the end of the year and the dies only struck a smaller amount of coins before being replaced with dies for the next year. I guess when you are dealing with machinery, there are any number of things that could hapen that may reduce a striking run.

[Maineman750]

I do understand about the rim cuds Bob, but they still had to see them.Even just one day should produce a huge amount of any of the varieties I've used as an example.Having worked 8 years in a machine shop,I wouldn't have lasted a month if I ran parts all day off one set up without spot checking to be sure nothing had changed.I just find it tough to believe that even a government facility would be that lacking in the QC Dept.


I just took this excerpt from a US Mint slide show:
"The coins fill a collection box called a trap. An inspector checks the coins to see if they meet United States Mint quality standards.

Coins are compared to both visual and fill standards. Next, critical Statistical Process Control (SPC) and capability quality data are entered into the United States Mint's data collection system to track key processes.If an error is spotted, coins in the collection box are scrapped and sent to coin destruction machines called wafflers. These machines use two high-pressure rollers to impress a ridged pattern into the metal. Distorted and mutilated, the metal loses denomination value. However, it is recycled for future use.

[riff]

here is a pretty cool old '40's era movie about the coin making process i found a minute ago. it covers everything from the raw metal, to the finished product. it kind of glossed over my question though.

http://www.youtube.com/watch?v=mBjD9N1APsw

[mustbebob]

I wasn't the one who said they didn't check coins Roger. That was Chucks reply, and as far as the accuracy of his statement is concerned, I really don't know. I was only looking to give a couple of reasons why some of them may be scarce. There very well may be 100 thousand 1972P Die -004s out there, but they just have never been reported, or they are all sitting in my storage locker with the other million coins During the Mint tour I took in 1998, they did stop at a couple of the traps and looked at coins. However, it was with a small loupe. I wouldn't of expected them to catch a Die-004 that way either. You also need to consider that the 1972P Die-004 is a rather minor doubled die. If I was an inspector and did manage to see that one, it would have been too minor to scrap an entire run for, and I would have let it go. As far as the Close AMs..uness you are specifically looking for that sort of thing, I don't know if it would have ever been caught.
Of course there is always human error. If you are looking at hundreds of dies a day, or thousands of coins, I am sure many things are missed.

[Maineman750]

Well, I'm guessing nobdy read the text I posted above, but yes they do check coins for problems.Here is the slide show : http://www.usmint.gov/mint_tours/?action=vtshell

And I also saw a picture of a worker inspecting coins at the press, they compare them to a large photo taped on the side of the press.

Bob...why aren't you somewhere else ?

[mustbebob]

Bob...why aren't you somewhere else ?

Tired of waiting at Hospital. Little Gabriel was chasing all the nurses around and they kicked us out ! Actually...my daughter told me to wait at home...she's getting a little bitchy. I have no idea why

[GrumpyEd]

I remember reading that the 55 DDO was noticed in the trap but some had already overflowed or been mixed in with a large group. The only way to get them all would have been scrap the large group but the mint needed to ship coins so they let the large group ship with some of the DDOs.

I'm don't think that story matches all of the evidence. The entire population of 55 DDOs is a few bricks worth. Not long ago there was discovery of a 55 DDO with lots of polish lines and clash rework. That makes me think they ran the die until it clashed and they reworked it and then caught the DDOs soon after the rework (since most do not have it). That still doesn't explain why the population is not bigger since (if the info is correct) that the reworked one was a later die state and I think many coins would be produced before the die state changed. I'm no expert on die states, maybe an explanation is that they ran the die for only a short time and clashed it then reworked it and caught it soon after and the one with the polish lines might be the same die state but reworked BUT others say it is a later state based on wear other than the rework.

Maybe some experts have ideas about it, it would be great to hear it! Lets hear some!

Here's a link that shows the 55 DDO from the die after rework:

http://forums.collectors.com/messageview.cfm?catid=26&threadid=792187

I think many other more minor DDO examples are ones where the mint might ignore them. If there's a low population it's because the die failed fast or the year ended or they're so minor that most are not ever found by searchers. There are many searchers that look for big DDOs but a lot less that would even notice a 72 die-4 and evidence shows the die was failing early. Coins like that might be found in already searched rolls because the searchers only looked for the big ones.

I doubt that in 1992 the mint workers were looking for CAMs, however many they made were probably a small fraction of the coins since thousands of die pairs were used. Still the population seems small so maybe the dies were not used long or were eventually noticed and scrapped.

[jcuve]

It's hard to fully speculate on the '55 without seeing an example with the abrasion marks in person. I seriously doubt it was LDS. Wexler notes it as being stage B on his site, that's without any info on die state. The photos of that stage don't strike me as being LDS, maybe EMDS/MDS.

I think it is safe to say that many of the larger doubled dies, with lower populations, were somehow identified and pulled. As to when, or the specifics, we may never know.

[coppercoins]

Okay..to clarify...

They DO check the coins to make sure the machines are working correctly and aren't minting total junk, but the inspection of the actual DESIGN on the die ends at the die making stage. Once the dies are hung on the press to mint coins, they are considered good to make coins and the DESIGN on the coins are not checked thereafter. ANY facility that makes hundreds of millions of anything each year is going to spot check the product for quality, but they DO NOT sit with microscopes and make sure there aren't any doubled columns on the cents they mint.