Cerrotru Alloy

Cerrotru is a low-temperature, lead-free metal alloy containing 42% Tin and 58% Bismuth that melts at just 281F. Cerrotru has only slight expansion during solidification.

Our Cerrotru is cast in 1 lb ingots and is sold by the LB.

Discounts available on quantity orders:

6-15 lbs = $2.50 discount per pound
16-25 lbs = $5.00 discount per pound
26+ lbs = please contact for pricing


Cerrotru Alloy

Typical Applications

With the density of .315 lbs./In3 (or 8.7 g/cc), Cerrotru — a Eutectic alloy—is used to anchor shafts in permanent magnet rotors, aircraft assembly fixtures, metallic components in glass, magnets in fixtures. At the net maximum expansion of .0005″ per inch and the melting temperature is 281 °F (or 138.0 °C), Cerrotru can also be used in a variety of manufacturing processes, where plastics are heavily involved, such as injection molding, encapsulating, plastic sheet forming, denture production, prosthetic development, potting electronic components and low-temperature lead-free solder.

Typical Uses of Specific Low Melting Point Alloys:  

a) 158º Fusible Alloy – Anchor bushings in drill jigs, Internal or external support of delicate parts for machining, Cores for spinning, Fusible mandrels in filament winding., Fiberglas lamination, Drop hammer and embossing dies, Tube bending filler (up to 1-3/4″ diameter) ,Heat transfer medium in processing plastics, chemicals, etc. (up to 255°F), Shielding Blocks for Nuclear Medicine

b) 158º-190º Fusible Alloy- Toy soldier casting , Proof casting cavities (threads, dies, moulds, blind holes), Duplicate patterns in foundry match-plate making, Supporting work pieces while machining, Spray coating wood patterns, Masks for electroplating and spray-painting.

c) 203º Fusible Alloy- Cadmium Free alternative for LOW 158 for Nuclear Medicine.

d) 212º Fusible Alloy- A tin/bismuth alloy (containing lead) which melts at the low temperature of 212º.

e) 217-440º Fusible Alloy-  Originated by GE for anchoring punches in dies, Anchor non-moving parts in machinery; hold down bolts in concrete floors, locator parts in tooling docks, Split jaw chucks, jigs, fixtures, Metal forming dies, form blocks, joggle jaws, Repairing broken dies, Filling blowholes in castings.

f) 255º Fusible Alloy- Anchor cutlery handles, inserts in wood, metal parts in glass (Tuflex doors), Make fusible spinning chucks, Mandrel for electroforms, Drop hammer dies, stretch form blocks, Moulds for plaster, plastics, Tube bending filler (over 1-3/4″ diameter), Hydrodynamic forming, seamless fittings, Duplicate patterns in pottery and foundry, Liquid metal in autoclaves, heat-treating, Heat transfer (Up to 327 °F), Shielding Blocks for Nuclear Medicine

g) 281º Fusible Alloy- Anchor shafts in permanent magnet rotors, locator members in aircraft assembly fixtures, metal parts in glass, magnets in fixtures, Make nests for parts in jigs and dial feed stations, Cores for electroforming, Embossing dies, form blocks, Joggle jaws, Lost wax pattern dies, Duplicate foundry patterns, Tracer models in profiling, Molds for plastics, sheet plastics, plastic teeth, prosthetic development, Potting electronic components, Laps for rifle barrels.

h) 281-338º Fusible Alloy- Parallels LOW 281 in its end uses, Electroforming mandrels, lost wax pattern dies due to greater dimensional accuracy, Holding jet turbine engine blades for machining.

i) Note: Other low melting fusible alloys are available


A low melting fusible alloy.

Chemical Name: Bismuth-Lead, Tin, Cadmium & Indium Alloy
Chemical Formula: Combinations of Bi + Pb + Sn + Cd + In

Cerro Alloy Grades Available:

Cerro Alloy Name Cerro Alloy Number Melting Temperature
CERROLOW-117 4470-2 117°F
CERROBEND 5000-7 174°F
CERROLOW-174 5700-1 174°F
CERROTRU 5800-2 281°F



Weight 1 lbs
Dimensions 6 × 1 × 1 in