Calculate Weight & Metal - Jewelry Casting Tips & Tricks
Calculating Metal Weights for Casting
To begin determining the weight of the metal to be used, all rubber base weights must be measured via scale. Write the exact weight of your rubber base on the bases themselves using a felt pen.
After mounting your wax tree to your rubber base, record the weight of the rubber sprue base and the wax tree combined. Deduct the rubber sprue base weight from the total weight.
This will give you your net wax weight.
To simplify matters, let's assume the specific weight of wax is "1".
Metal weight is calculated by multiplying wax weight by the specific weight of the metal:
| Metal | Spec. weight in g/cm³ |
| Water, wax | 1.00 |
| Aluminum | 2.70 |
| Steel | 7.85 |
| Brass | 8.40 |
| Bronze | 8.80 |
| Silver | 10.50 |
| Nickel silver | 8.40 |
| Gold 333 | 10.90 |
| Gold 585 | 13.70 |
| Gold 750 | 15.20 |
| Gold 900 | 17.40 |
| Palladium 950 | 12.00 |
| Platinum 950 | 20.70 |
Example Wax Weight Calculation: Combined weight (Wax + rubber base) = 43.5g. Subtract weight of rubber base (38g) = 5.5g (wax weight).
| Metal | Wax weight in grams x Specific weight |
Metal weight in grams |
| Silver | 5.5 g x 10.5 | 57.75 |
| Gold 750 | 5.5 x 15.20 | 83.60 |
After the calculation: Place flask cylinder and fix it carefully on the rubber base. Do not touch wax pieces. Mark the rubber bases clearly to avoid confusion when you prepare several flasks!
Log In