Reworked dies........

[Tiger 1]

I was curious about 'reworked' dies. This terminology is frequently used to describe a frame or core that may not neatly fit unto a known type or maker pattern.

This is solely an opinion question as we don't know for sure.

How many makers in your oponion used 'reworked' dies?

This also begs a second question.

Why would a company 'rework' a hardened tool steel die when hubbing a new die from the master hub be much easier? The hubbing would be done on a soft or annealed tool steel blank before it was hardened and tempered for production use.

There are no right or wrong answers here. Just looking to hear opinions.

Thanks.

Tony

[streptile]

Hi Tony,

In my opinion there is no such thing as a "re-worked die."

I am very open to changing this opinion, but I have seen little to convince me that such a thing is possible, and plenty to convince me that it is not.

I suspect similar dies are made by making another die all together, from the same master.

In my opinion, your question is a very good one, about a subject that very much needs exploration. I hope some of the RK guys will see this thread and comment.

[Leroy]

This is a very interesting subject and one which has been touched on, peripherally, in many threads.

IMO, there are many possible children of a "mother die", but only one "mother" at a time.

[Biro]

I was curious about 'reworked' dies. This terminology is frequently used to describe a frame or core that may not neatly fit unto a known type or maker....Tony

I would have to say I see this phrase 're-worked dies' used predominantly in relation to WW2 spangen that are nearly but not quite fitting the exact die characteristics of something else (the length of veins on wing feathers being a classic example)

My question - which merely expands on yours Tony - is if a difference between two items is as minuscule as an extra millimeter of 'feather vein' and needs microscopic photography to be discovered in the first place, then why on earth would there have been any need to "re-work the dies".

Surely if you could 'rework a die' you would do it only to make substantial aesthetic alterations (for some reason) or to fix something that was terminally broken, and usually, neither scenario applies!!

I'm not suggesting reworking didn't or can't happen - I dont know - I have great suspicions a Godet PLM eagle may have been "re-worked" in some fashion to form the 'Schickle' PLM eagle but can't post pictures from where I am right now to substantiate that. Whether that was a re-working of some sort of 'master die' or merely a casting process, i dont know. Maybe later....

Suffice to say, it is an extremely over-used and misunderstood phrase and I look forward to learning from some of our more experienced engineering types about just what is and isn't possible and feasible in relation to 're-working' master dies.


An excellent topic my friend

Thanks for the photos by the way - jaw dropping!!

Marshall

[Douglas 5]

re: reworked dies :
A term I as well picked up here and used at first to describ the variation in appearance of frames by the same maker .
Realizing later after a visit to the town cast and die foundry that one absolutly cannot grid, file ,chizel etc on hardened steel -
re-working a hardened die is not possible - it just chips .... polishing is all one can do .
The next resonable possibilty I had that could account for the differences was a copy off a master die . After seeing the pictures
I was some what close but it turned out to be much more ingenious procedure . To this day I wish very much for the benefit
of all collectors that the owner would reconsider and have at least some of his pictures and documents posted .

Regards Douglas

[Tiger 1]

Interesting thoughts all.

I was doing some reading up in a related numistmatic field when that question struck me. Coins and military medals and decorations have much in common when it comes to manufacture of each.

What I am surprised of is the longevity of a die used to stamp very hard coins such as the US 5 cent piece. The planchetes for this coin is 75% copper and 25% nickle. This alloy is very hard and thus very tough on the dies. Average longevity of these dies are about one quarter million coins before the dies become tired.

Just some thoughts.

Tony

[Eric Von Rader]

I have had the privilege of working as a Tool Maker building many Injection molds draw, punch, progressive dies, and worked in a foundry as an engineer for a small stent. Also was a tooling engineer in die casting for many years.

Steel refurbishments/repair/ heat treatment/ special steel coating technology has came a long way since WW2. That being said depending on how the tool was made IE type of steel, steel hardness,type of wear or damage, would determine the method of "repairs" or "refurbishment". Welding up a small die would have been extremely difficult in WW2 and causes other problems if not done properly. Hand polish/repairs would had been more practical but depending on the type of wear would determine if a new die would be needed. My experience would lead me to believe that very minor repairs would/could had done, but rarely needed as the materials being used were soft and easy to stamp. Of course a fresh die will make super sharp and crisp details, ever look at an early GO dagger by Alcoso vs a late war? Or even some of the late war badges. Once a die is repaired it would be noticeable under magnification, as the steel is removed or "displaced" its gone for good. One can hand work out minor flaws or dings to make them less noticeable.

[Leroy]

What would make a hardened steel die, used for (at the most) a few thousand stampings of a relatively soft and thin metal (i.e. silver cross frames) fail? Would it be a defect in the die itself or would it be caused, rather, by some fault in how the die was used (alignment, pressure, etc.)?

[Eric Von Rader]

What would make a hardened steel die, used for (at the most) a few thousand stampings of a relatively soft and thin metal (i.e. silver cross frames) fail? Would it be a defect in the die itself or would it be caused, rather, by some fault in how the die was used (alignment, pressure, etc.)?

Great point, if RK were truly limited and the production lots small, why spend the funds to build a higher quality long lasting die? It would be easy to damage a die by improper press settings, varying sheet stock thickness, mis aligned dowel pins, press platens, over tonnage settings, (crush the die) or the wild card......stupidity.

[Bob Hritz]

Setting the 'drift' or throw of a press is a very special skill. Any press must be set to exact measurement of the closed die and material. If the drift is too tight, the die will fracture. If the drift is too short, the stamed article will not fill the die and will come out weak in detail. Either is wasteful.

There is repair of fractured dies by pressing them into a die block, which will hold the die tight and allow for further use. If there is damage to the die from chipping, the stamped article will have to fe hand finished, which is not cost effective.

Many dies can be made from the positive mother die. When the hardened mother die is forced into the annealed daughter die, there is still hand finishing necessary to the daughter die before it is hardened. This usually consists of polishing, or blasting with fine particulates to get the fine finish and frosting, respectfully, from the finished stamping.

There is no alchemy or black art involved in die making and the procedure has been around for many decades. Coins have been stamped for thousands of years, from the crudest 'cobs' made by a spin thrust press to fine proof like coins made on machinery that has been used for well over 150 years.

A hardened tool steel die that shatters or cracks is more often replaced than repaired to save in hand work finishing.

Dies do require maintainence. They are prone to rust and need to be regularily cleaned with a serices of wire hand brushes from soft copper to stiff steel. The dies get polluted with oil, dirt, and the material from the stampedings. These are hand brused clean and the use of copper picks are required if pollution is in deeper places of the die. They must be cleaned and kept in polish to produce quality strikes. We can see the results of polluted dies from many of the flaws, which appear as dents or divits in the finished product. We see the result of die cracks from raised flaws on the finished product.

Bob Hritz (Worked with a number of men missing fingers from inproper die press use)

[Tiger 1]

Well said Bob.

Tony

[Tiger 1]

Marshall,

Glad you like them. Onward snd upward with the craft. Enjoy them my friend.

Tony