How to hammer this pattern into a die for fine-silver coinmaking

[HammerTitanGuy]

Hello everyone,

I am a silversmith. I am working on my own watch dials. Using a foredom power-graver hammer and a ball nose steel-anvil tip, I have hammered this pattern into my silver blank. The effect is that the force from the hammer has domed this coin. This effect is actually quite desireable and I would like to replicate it.

Someone recommend I use a hydraulic press with a die, and press this pattern into the silver blank.

This is a picture of the silver blank I want to get (

http://imgur.com/s1ZW0X0

)

This a half cross-section of the above (

http://imgur.com/xFmVedN

)

I tried to engrave the die steel (pre heat-treated) with my ball nose steel anvil-tip (used in my engraving) however it bent the tip. Silver is malleable and soft, so the hammer strokes are nice and deep. However, I am unable to replicate this effect in my die.

I would like any guidance about how to make the die. The reference image is of a coin about 38mm/1.5inches in diameter. Would like to retain the scale as seen in the image below. The goal is to have this hammered finish on the dome of the die.

Could you please recommend the best way to make my die so I can get the effect on silver (as linked below)? Thank you for your time.

 

[Leonardo]

I would suggest you to contact a mechanic workshop with a EDM machine. (EDM: Electrical Discharge Machining)
This machines use a copper electrode previously mechanized or engraved with the shape you want to reproduce on the steel to erode the shape on the surface.

You can engrave a thick piece of copper with your pattern making the electrode and then give it to the workshop to make the die in steel.
The copper material should be thick enough to let making a threaded hole on the opposite side to provide means to hold the electrode in the EDM machine.

Once you find the workshop they surely be happy to prepare the right material and give it to you so you can engrave your patter on the surface.

Hope this help a bit!

 

[gtsport]

Engraving pre heat treated steel will destroy tools. you need to engrave annealed tool steel, then have it hardened. O-1, W-1 S-2, S-7, A-2, are all good steels for this purpose

 

[Dave London]

Use a hand punch and suitable hammer

 

[Ken Denning]

The metal is doming because it is being stretched unevenly. Each blow from a "ball" end hammer will stretch and thin the metal in all directions on the side being struck. One alternative is to chase and stretch the metal evenly all the way to the outside edge. This technique is used in raising.

You could anneal the metal after texturing and either press it flat with a die press or use a rawhide mallet. It could then be re-tempered after flattening.

Another possibility is to make a pattern in copper and have a duplicate ground in the die material with a CNC machine.

 

[silverchip]

An easy answer is gonna be a little complicated but I think you can getter dun. I make dies for blanking silver rounds and other parts for myself. The texture you want can be obtained with a rolling mill and texture plate. Then blank out our round blank with a simple die and punch using a hydraulic press. Texture plates are available from different makers online for a reasonable price. My dies are simple 01 bottom plate with a hole bored through on a lathe and the punch can be 1018 steel if you want but O1 can be used as well and both can be heat treated if you want to go down that rabbit hole that far.

 

[gtsport]

I'd go with silverchip's idea. seems the most cost effective.

 

[Goldjockey]

Harper Mfg. in Idaho may be able to make a die for your pattern. Most people use a press to impress the die into metal. However, we used to use a 5 lb sledge hammer and stump mounted anvil to hand stamp large designs and patterns into precious metal. https://makersrow.com/harper-manufacturing-co

Also the pattern itself looks pretty basic. Seems to me you could anneal a flat piece of steel, use a fine rounded polished hardened steel punch to create the finely hammered surface texture in the steel plate. Heat treat the plate to desired hardness, polish the hammered surface of the steel plate, and then use a rolling mill, or hydraulic press to transfer the texture to fine silver strip before drilling the center hole, marking your circumference with a divider and cutting to size.

 

[HammerTitanGuy]

Harper Mfg. in Idaho may be able to make a die for your pattern. Most people use a press to impress the die into metal. However, we used to use a 5 lb sledge hammer and stump mounted anvil to hand stamp large designs and patterns into precious metal. https://makersrow.com/harper-manufacturing-co

Also the pattern itself looks pretty basic. Seems to me you could anneal a flat piece of steel, use a hardened steel punch to create the finely hammered surface texture in the steel plate. Heat treat the plate to desired hardness, polish the hammered surface of the steel plate, and then use a rolling mill, or hydraulic press to transfer the texture to sterling strip before cutting to size and shape, and drilling the center hole.

Hello,

Thank you so much for your response. My sincerest apologies for not being clear in my original post however I have changed my post so it better reflects what I am looking to do. Thank you for linking their site, I am located in South-Asia however I shall get in touch with them and discuss feasibility of die production.

I actually need to create that hammered surface on a domed surface, not a flat surface (as seen in the reference above). How might you change your advice based on the updated information?

 

[HammerTitanGuy]

An easy answer is gonna be a little complicated but I think you can getter dun. I make dies for blanking silver rounds and other parts for myself. The texture you want can be obtained with a rolling mill and texture plate. Then blank out our round blank with a simple die and punch using a hydraulic press. Texture plates are available from different makers online for a reasonable price. My dies are simple 01 bottom plate with a hole bored through on a lathe and the punch can be 1018 steel if you want but O1 can be used as well and both can be heat treated if you want to go down that rabbit hole that far.

Thank you so much for your answer. I shall look into these techniques.

The metal is doming because it is being stretched unevenly. Each blow from a "ball" end hammer will stretch and thin the metal in all directions on the side being struck. One alternative is to chase and stretch the metal evenly all the way to the outside edge. This technique is used in raising.

You could anneal the metal after texturing and either press it flat with a die press or use a rawhide mallet. It could then be re-tempered after flattening.

Another possibility is to make a pattern in copper and have a duplicate ground in the die material with a CNC machine.

Thank you for explaining why it is doming. It makes perfect sense now.

Engraving pre heat treated steel will destroy tools. you need to engrave annealed tool steel, then have it hardened. O-1, W-1 S-2, S-7, A-2, are all good steels for this purpose

Thank you for the recommendations. I shall find out whether these steels are available in my city and get on it!

I would suggest you to contact a mechanic workshop with a EDM machine. (EDM: Electrical Discharge Machining)
This machines use a copper electrode previously mechanized or engraved with the shape you want to reproduce on the steel to erode the shape on the surface.

You can engrave a thick piece of copper with your pattern making the electrode and then give it to the workshop to make the die in steel.
The copper material should be thick enough to let making a threaded hole on the opposite side to provide means to hold the electrode in the EDM machine.

Once you find the workshop they surely be happy to prepare the right material and give it to you so you can engrave your patter on the surface.

Hope this help a bit!

Thank you for your advice! Unfortunately there are no EDM Machine providers in my city however I there are a few in my country. I shall find out and get in touch with them to discuss the feasibility. Thank you for explaining the process!

 

[Goldjockey]

Hello,

Thank you so much for your response. My sincerest apologies for not being clear in my original post however I have changed my post so it better reflects what I am looking to do. Thank you for linking their site, I am located in South-Asia however I shall get in touch with them and discuss feasibility of die production.

I actually need to create that hammered surface on a domed surface, not a flat surface (as seen in the reference above). How might you change your advice based on the updated information?

To preface a bit, my background is in hand fabricated jewelry design and production using many of the traditional processes and techniques employed in traditional Navajo silversmithing, so my suggestions are from that perspective.

Presuming the dome has to be precise, and that you intend to make these in quantity, I would look for a company that could make dies to texture, dome, and cut the parts in one or two processes.

Dies can be quite expensive though, so for limited production, I would texture fine silver strip with a rolling mill as recommended in my previous post. Drill and cut the watch faces to a template, either by hand or with a cutting die or laser. Grind, hone, and polish a doming die to the correct size, shape, and depth, use a cottonwood or similar soft wood stump, and use the polished steel doming die to create the negative impression for doming in the face of the wooden stump. Dome the watch faces, hand polish with wheels and compound, or machine finish with tumbling media, and ceramic polishing media.

 

[Chujybear]

What you are trying to do, it should not be a problem to apply your texture to your watch face first, and then to shape it. I’ve had success with considerably deeper domes and even draws without effecting the texture.
if you are worried you could use a Teflon, or wood dapping block. Then your design would really be safe.
It looks like you are just after a pebbly, or distressed surface, and not the smooth exact pattern that comes with engraving. If I am reading that right, you could use a carbide or diamond burr in your hardened die plates. Just bear in mind that every piece you grind will be raised in the final product (captain obvious

 

[HammerTitanGuy]

Reheating the pattern removes the shine (which comes from hitting the silver with the polished hammer). Repolishing will remove the texture (polishing agents erode details). How to repolish then?

The metal is doming because it is being stretched unevenly. Each blow from a "ball" end hammer will stretch and thin the metal in all directions on the side being struck. One alternative is to chase and stretch the metal evenly all the way to the outside edge. This technique is used in raising.

You could anneal the metal after texturing and either press it flat with a die press or use a rawhide mallet. It could then be re-tempered after flattening.

Another possibility is to make a pattern in copper and have a duplicate ground in the die material with a CNC machine.