Category: Jewelry Making
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Subject: Jewelry making with 925 silver
Question: What is the difference between "Dead soft," "hard," and "half hard" when buying raw sheet silver? I know when buying solder, it refers to the firing temperature - is it the same with 20 gauge sheet silver? Or does it have something to do with the pliability?

Answer: hello Marsha,
actually the terms refer to temper of the metal and the amount or rqather the degree of compaction of the crystalline structure- Dead soft refers to annealed metal that is easiest to work- most metals are sold in dead soft or half hard temper- you can always request your materials be sent to you DS-I don't know of a single dealer that won't honour that request. If you buy half hard and are going to use the 20 g sheet for cutting out a backing plate to solder a bezel to that would be acceptable, however if more than one operation is to be carried out you would need to anneal to make bends, adjust prongs, etc as metal work hardens easily- particularly lower karat golds and sterling.Fine silver and high karat golds contain less (or no ) copper as in the case of golds 18 kt and upwards fine silver and very littlle copper per gram of fine gold so it is more forgiving in terms of workability and requires less annealing. Many jewelrs don't use fine silver arguing that it is too soft-I use exclusively fine silver and work harden pieces to a most durable finished piece- also using .999 silver means less chance of firescale since no copper is in the material and hence, no cupric oxides can build up-although it is a good practice to dip anything soldered in an antifirescale/ firecoat flux like Cupronil, by 4S labs ( i sell it as do many jewelry suppliers because it is one of the more consistent and to me most reliable formulas for silverwork on the market- and the manufacturer is a traditional native american silversmith that has been selling the product which is based on a Hopi traditional formula since the early 1970's)..that formula had been used by the hopi for many years before 3S began selling it.It has never failed as a dip to prevent firescale or a flux for all grades of solder and is the least toxic of any others available-though I do use batterns type flux when working 22kt or higher gold when there are more than three joins to be made in a particular element, Cupronil works best for an all purpose flux/firecoat and is handier than making ones own pripp's type flux/firecoat in one consistent product..
As for 20 gauge sheet,or any gauge you choose you get the maximum weight buying full hard as the crystals are fully compacted, but for practicality I personally buy everything dead soft to save time- the weight loss is negligible - if you look at a catalogue like Hoover and Strong's, they print the weight per foot or inch of various metals- looking at that may help illustrate the minute differences in weights in various tempers.
Solder flow points are not exacrtly the same- they simply indicate the point at which the compound flows having no relation to hard metal, or soft metal- hard solder is used to make the first in a series of soldering operations, medium to add onto that and easy to add finishing touches if necessary to silverwork..with gold particularly higher karats you can use hard up to three operations without it burning out the binders in the solder ( zinc oxides) that allowfor a clean join.
I recommend your reading Tim McCreight's The Complete Metalsmith for a really good background in both metal tempers and solder flow differences..there are a number of other authors as well that define it exceptionally well-Harold O'Connor's "Jewelers Bench Reference" is a particularly good source of info as is Hoover and Strong's refernce section in the back of their catalogues and on line.
O hope this helps clarify the differences in temper as to metals and flow points as to solder for you..