Kat's Casting Notes & Calculations

Sterling Silver Conversion

Measure the grams of Formlabs Castable Resin v2 and enter it in the first column. The second column is the quantity of items, and the third column is an estimate of the grams of metal, and the last column includes an extra percentage that is entered in the box at the top, rounded up to the nearest gram. 

I am working on a fix to NOT round up the last column to a whole number, but instead give it one or two decimal places, or give the option to increase the precision for more expensive metals.

This is ONLY approximate...I'm not a javascript programmer. I have tested the functionality, but would recommend you double-check any questionable numbers. I'll tweak the layout along the way, like resizing columns and lining up the metals.


EXTRA METAL percentage, without the percent sign (example—enter "10" for 10%):    %

Sterling Silver 24K Yellow Gold 18K Yellow Gold 14K Yellow Gold 10K Yellow Gold
Fine Silver Platinum 18K White Gold 14K White Gold 10K White Gold
Caster's Brass Caster's White Bronze Ancient Bronze Yellow Bronze Manganese Bronze
Nickel Silver Aluminum Copper Pewter* Iron (pure)


Grams of
Castable Resin

Item Qty

Description (optional)

Grams of Metal

Grams of Metal + EXTRA%, rounded up

(EXTRA METAL setting above is needed to see total grams of metal)

* The legal specific gravity of Pewter in France is 7.764, however this calculator uses 7.4 which is more common in the US.

Click for a larger version

Specific Gravity Chart and Formlabs Castable Resin Conversion

This chart shows the specific gravity of different precious metals, but also includes the factor needed to convert the weight of a model printed on a Formlabs Form 1 or 2 printer in Formlabs' castable resin. The chart technically is for the v2 of castable resin, but it works well for both versions.

This information is incorporated into the Castable Resin/Metals conversion calculator above. The chart shows the specific gravity and factors used in the calculations.