Cerrosafe

Cerrosafe is a fusible alloy with a low melting point. It is a non-eutectic mixture consisting of 42.5% bismuth, 37.7% lead, 11.3% tin, and 8.5% cadmium that melts between 70 °C (158 °F) and 88 °C (190 °F). It is useful for making reference castings whose dimensions can be correlated to those of the mold or other template due to its well-known thermal expansion properties during cooling. The alloy contracts during the first 30 minutes, allowing easy removal from a mold, then expands during the next 30 minutes to return to the exact original size. It then continues expanding at a known rate for 200 hours, allowing conversion of measurements of the casting back to those of the mold.[1][2]

Similar metals

AlloyMelting pointEutectic?Bismuth
%
Lead
%
Tin
%
Indium
%
Cadmium
%
Thallium
%
Gallium
%
Antimony
%
Rose's metal98 °C (208 °F)No502525
Cerrosafe74 °C (165 °F)No42.537.711.38.5
Wood's metal70 °C (158 °F)Yes5026.713.310
Field's metal62 °C (144 °F)Yes32.516.551
Cerrolow 13658 °C (136 °F)Yes49181221
Cerrolow 11747.2 °C (117 °F)Yes44.722.68.319.15.3
Bi-Pb-Sn-Cd-In-Tl41.5 °C (107 °F)Yes40.322.210.717.78.11.1
Gallium29.8 °C (86 °F)Pure metal100
Galinstan−19 °C (−2 °F)No<1.59.5–10.521–2268–69<1.5


References

  1. "Brownells Cerrosafe® Chamber Casting Alloy". Archived from the original on September 18, 2017. Retrieved September 18, 2017.
  2. "CS Alloys Safe 165, Cerrosafe". Retrieved September 18, 2017.