Rose's metal

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

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

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

Similar metals

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

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