BATT™ Alloy was developed for the purpose of casting hard, dimensionally stable, nontoxic polishing laps for gem faceting applications.

Tin and its alloys such as solders and type metal have made excellent faceting laps because of their ability to become "charged" with diamond and other polishes. Tin's low coefficient of friction or lubricity minimizes grabbing or dragging of the lap surface against the stone. But lead in these alloys adds no real benefits, and, with the use of acidic coolants such as vinegar, can produces toxic mists.

Pure tin's biggest problem, and one which is also present in many of its alloys is that it creeps in use, so is not dimensionally stable. It never work-hardens. This is beneficial when people are drawing or spinning deep shapes in pewter. Often with pure tin, the meets of the facets are not as hard as we would like them. So commercial laminated tin laps work well, at first, but become "bumpy" or "Orange peeled", and thinner at the edges.

The new alloy, which has completed its SEVENTH year, and now used by THOUSANDS of experienced and beginning gemcutters was named "BATT".

Being solid castings, finished on both sides, BATT ™ laps are more versatile than the one-sided laminated laps.

Because they are solid castings, they may be resurfaced many times, to provide years of use!

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Tuning the metallurgy:

In this metallograph, note the highly ordered grain structure in "BATT" as various alloying components sequentially crystallize when the alloy cools. Here, it is easy to see why the alloy can trap abrasive or polish grains.

Another purpose of this alloy is also to provide better performance on water suspensions of common polishes, as well as with diamond compounds.

Comparative Hardnesses of some tin alloys: