Zak Jewelry Tools

Castaldo® Molding Rubber - 5 lb. Ready Cut

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Castaldo® Molding Rubber. Just enough jewelry molding rubber to make 15-25 standard size jewelry molds. Available in White Label® (regular/firm), Gold Label® (premium/soft) and No Shrink Pink®. Complete instructions are enclosed in each box. Strips measure 18" x 2 7/8th" x 1/8th" (45.7 cm x 7.3 cm x 3 mm). Instructions.

  Gold Label® White Label® No Shrink Pink®
Shore A Hardness 37.3 42.1 43.2
Vulcanizes at: 307 ̊F/ 152 ̊C 307 ̊F/ 152 ̊C Variable*
Rubber shrinkage 2.1% 2.3% As low as 0.0%
Elongation before break 706% 688% 728%
Tensile strength before break

Very Strong

2,475 psi

13.9 n/mm²

Very Strong

2,215 psi

15.3 n/mm²

Strong

1,116 psi

7.7 n/mm²

Tear Strength Die C before break

134 lb./in.

23.4 n/mm

137 lb./in.

24 n/mm

81 lb./in.

14.2 n/mm

Uses Strong, flexible molds Strong, firm molds Strong, 0% shrinkage molds
Color Natural tan Natural tan Pink
MSDS Here Here Here