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Rose's metal

From Wikipedia, the free encyclopedia
Rose-shaped cast of Rose's metal

Rose's metal, Rose metal or Rose's alloy is a fusible alloy with a low melting point.

Rose's metal consists of 50% bismuth, 25–28% lead and 22–25% tin. Its melting point is between 94 and 98 °C (201 and 208 °F). The alloy does not appreciably contract or expand on solidification, this characteristic being a function of its bismuth percentage, but does slightly contract on cooling.[1]

Uses

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Rose's metal has several common uses:

  1. As a solder. It was used to secure cast iron railings and balusters in pockets in stone bases and steps.
  2. As a heat transfer medium in heating baths.
  3. As a malleable filling to prevent tubes and pipes from crimping when bent. Rose's metal is melted and poured into the tube. It then solidifies in place but remains malleable. This allows the tube or pipe to be bent and reworked without crimping. After the desired shape is achieved the Rose's metal is remelted and removed, leaving the pipe or tube in its modified shape.

History

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It was discovered by the German chemist Valentin Rose the Elder, the grandfather of Heinrich Rose.

Similar metals

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Alloy Melting point Eutectic? Bismuth
%
Lead
%
Tin
%
Indium
%
Cadmium
%
Thallium
%
Gallium
%
Antimony
%
Rose's metal 98 °C (208 °F) no 50 25 25
Cerrosafe 74 °C (165 °F) no 42.5 37.7 11.3 8.5
Wood's metal 70 °C (158 °F) yes 50 26.7 13.3 10
Field's metal 62 °C (144 °F) yes 32.5 16.5 51
Cerrolow 136 58 °C (136 °F) yes 49 18 12 21
Cerrolow 117 47.2 °C (117 °F) yes 44.7 22.6 8.3 19.1 5.3
Bi-Pb-Sn-Cd-In-Tl 41.5 °C (107 °F) yes 40.3 22.2 10.7 17.7 8.1 1.1
Gallium 30.0 °C (86 °F) Pure metal - - - - - - 100
Galinstan −19 °C (−2 °F) no <1.5 9.5–10.5 21–22 68–69 <1.5

References

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  1. ^ "Low melting-point (fusible) alloys" (PDF). Belmont Metals. Retrieved 5 December 2019.