If you like fine silver, you’re going to love Argentium® Sterling 970

What is Argentium® Sterling Silver 970?To help clarify what AS 970 is, here are a couple of simple definitions to help describe the differences:

Fine Silver: More than 999/1,000 pure silver (99.9% pure silver). Fine silver is considered by many to be too soft for fabrication and use in many forms of jewelry.

Sterling Silver: An alloy of fine silver (92.5%) and other metals, usually copper (7.5%). US law states that all objects marked "sterling," "925" or "925/1000" must contain no less than 92.5% fine silver.

Argentium® Sterling Silver 925: Argentium® Sterling Silver 925 contains at least 92.5% fine silver, but replaces a small amount of the copper that is usually the other 7.5% with germanium.

Argentium® Sterling Silver 970: Argentium® Sterling Silver 970 is like Argentium® Sterling Silver 925 except that it contains at least 97% fine silver.

Why use Argentium® Sterling Silver 970 instead of fine silver?
1. It also improves the tarnish resistance even further than AS 925.

2. Those who have trouble wearing regular sterling silver jewelry should have little or no trouble wearing AS 970 because of it's low copper content.

3. It‘s much harder! AS 970 can be precipitation hardened in the same manor that you would harden Argentium® Sterling 925.

How hard is it?
AS 970 will precipitation harden to the same hardness as AS 925 (approximately 120HV). After precipitation hardening AS 970 or AS 925, you should notice quite a difference, depending on the thickness of the metal, as I did when I precipitation hardened an adjustable ring http://argexp.blogspot.com/2005/08/heat-hardened-argentium-sterling.html .

To help get a better understanding as to how hard it is, please click on the following link http://argexp.blogspot.com/2006/04/hardness-argentium-sterling-vs-gold.html .

Where can you get it? As far as I know the only place to get it at this time is Stern-Leach.

How does it cast?
More to come soon!

Can't wear Sterling Silver? Try Argentium® Sterling instead

An acquaintance of mine has never been able to wear Sterling silver because it always leaves her skin black in a very short time. I told her about Argentium® Sterling Silver and asked her if she would be willing to be my Guinea Pig to see if she had the same reactions to Argentium® Sterling. I gave her a bracelet (pictured above) and I am pleased to report that she wore it for two weeks continuously without developing any black marks what so ever. Her daughter also had the same problem and has been wearing it for over three weeks. She too has had no problems.

The bracelet was made by fusing Argentium® Sterling Silver jump rings. I used My-T-Flux® to aid in the fusing of the jump rings.

Casting with Argentium® Sterling Silver - What does it look like?

When I cast with Argentium® Sterling silver, I use a torch (MAPP gas) and a centrifuge. After heating the crucible, I add the required amount of AS. After I have started to heat the Argentium® Sterling somewhat, I add a pinch of Borax. The AS melts quite quickly and as soon as it is fully molten, I release the centrifuge. Once the piece is cast, I let it air cool. This will help the Argentium® to become quite hard. Below is a picture of the button of a cast using Argentium® Sterling Silver.

After removing the cast from the flask, I bush it off with a toothbrush. The pictures below show a cast made from Argentium® Sterling Silver (left) and one made using regular Sterling Silver (right). The cast made from AS is somewhat gray but compared to the regular Sterling Silver, it is quite bright.

As you can see, there is quite a difference! The piece is ready to pickle.

Casting Flask Temperature: Additional Information

Peter Johns, the inventor of Argentium® Sterling, sent me the following information:

"We have found that flask temperature is not critical but metal temperature is. Metal temperature should be between 1740 F and 1800 F. Flask temperature should be what is normal in standard sterling for size and weight of the piece."

"If you are casting into a steel mould I always file all sides of the ingot before rolling. I always thought this was normal practice but I recently found somebody who was not doing it and they were not getting good results."

Question: Casting Flask Temperature.

Question: I am buying AS casting grain and will use it for vacumn casting wax models as well as ingot casting rough plate to mill into sheet metal. Do you have any cautions about casting and then milling the plate? What temperature do you have the flask at when you are ready to take it out of the kiln?

Cynthia Eid's article on Argentium® http://www.cynthiaeid.com/argentium_4-8.html should be very helpful to you. She recommends a flask temperature of below 1250F. I would recommend letting the crucible cool completely before removing the piece. Your casting will be very hard and you may see no need to precipitation harden it.

I haven't been able to afford a roller mill so I won't be much help there. Once you get comfortable with Argentium® Sterling you may want to try "super annealing". First dim the lights, then heat the Argentium® Sterling up to a slight red glow for a few seconds. Be very careful not to overheat the Argentium® Sterling. If you heat it as much as you would regular Sterling Silver it will be too hot. The trick is to quench the alloy just at the right time. Too late, it will only anneal as normal. Too soon, it will develop stress cracks. The time that is right is just after the red glow is gone when seen from a darkened room.