General Characteristics

In addition to having low melting temperatures CS Alloys are virtually non-shrinking; several expand or grow after they are solid. All are relatively soft and brittle. Some, like CS Alloys, work soften. All have high density, averaging about three cu. ins. per pound. The numbers in parenthesis refer to other CS Alloys literature giving more details on the specific end use. Write for your copy.

2# Cakes 2# Slabs 3/16" U Bars Special Shapes on Request Wire Typical End Uses Melting Point - Degree F Range (Degree F) (No definite melting point) Melting Point - Degree C Range (Degree C) (No definite melting point) Growth or Shrinkage After Casting Weight Lbs./In.3 Tensile Strength Lbs./In.2 Brinell Hardness No. Maximum Load 30 Seconds, Lbs./In.2 Safe Load Sustained Lbs./In.2 Electrical Conductivity Compared with pure cooper Compositions (%)
Low 117 Alloy X X X X No Use in jigging or fixturing delicate parts for machining (honeycomb), (B5 Supp. 3); dental models, prosthetic development work; proof casting (internal measurements), (E10); fusible element in safety devices (E3); radiopaque contrast medium in X-Ray; low temperature solder (E9) 117 - 47.2 - Initial Expansion. Shrinks to .0000" in 30 minutes Stable in 2 hours at -.0002" Per Inch .32 5400 12 - - 3.34% Bismuth: 44.7
Lead: 22.6
Tin: 8.3
Cadmium: 5.3
Indium: 19.1
Low 136 Alloy X No X X No Anchor parts for machining (jet blades), testing, inspection (A1); block lenses in optical manufacturing; proof casting (E10); fusible element in safety devices (sprinkler heads (E3); fusible cores in compound cores; low melt solder (E9); sealing adjustment screws. 136 - 57.8 - Initial Expansion. .0000" in one Hour Stable in 5 hours at -.0002" Per Inch .31 6300 14 - - 2.43% Bismuth: 49.0
Lead: 22.6
Tin: 12.0
Indium: 21.0
Bend Alloy X X X X 1/8 & up Anchor busings in drill jigs (A1); internal or external support of delicate parts for machining (B5); cores for spinning (B4); fusible mandrels in filament winding, fiber-glass lamination (C3); drop hammer and embossing dies (D6); tube bending filler (up to 1 3/4" diameter) (H3); heat transfer medium in processing plastics, chemicals, etc. (E4) 158 - 70 - Rapid Immediate Growth Maximum .0057" Per Inch .339 5590 9.2 10,000 300 4.17% Bismuth: 50.0
Lead: 26.67
Tin: 13.3
Cadmium: 10.0
Base Alloy X No X X 1/8 & up Anchor: Cutlery handles, inserts in wood, metal, plastics (A1); metal parts in glass (Turflex® doors) (A1). Make fusible spinning chucks (B4); mandrels for electroforms (C1); drop hammer dies, stretch form blocks (D6); molds for plaster, plastics (G2); filler for tube bending (tubes over 1 3/4" diameter) (H3); hydrodynamic forming, seamless fittings; duplicate patterns in pottery and foundry (F6); liquid metal in autoclaves, heat treating (E4). 255 - 124 - Initial Shrinkage Followed by Slow Growth Maximum .0022" Per Inch .380 6400 10.2 8,000 300 1.75% Bismuth: 55.5
Lead: 44.5
Tru Alloy X X X X 0 Anchor: Shafts in permanent magnet rotors, locator members in aircraft assembly fixtures, metal parts in glass magnets in fixtures (A1). Make nests for parts in jigs and dial feed stations (B5); cores for electroforming (C1); embossing dies, form blocks (D6); joggle jaws; lost wax pattern dies, duplicate foundry patterns (F6); tracer models in profiling (F7). Molds: For plastics (G2); encapsulating (G6); forming sheet plastics (G2); plastic teeth, prosthetic development; potting electronic components (G6); low temperature solder (E9); laps for rifle barrels. 281 - 138 - Net Expansion .0005" Per Inch Maximum .0005" Per Inch .315 8000 22 15,000 500 5.00% Bismuth: 58.0
Tin: 42.0
Low 147 Alloy X No X X 0 (Note slightly lower melting temperature than Bend) Will function about as well for same uses if slight freezing range is not objectionable. Some success has been reported in lens blocking by optix manufacturers. - 142-149 - 61-65 Rapid Immediate Growth Maximum .0052" Per Inch .342 4950 11 10,000 300 3.27% Bismuth: 48.0
Lead: 25.6
Tin: 12.8
Cadmium: 9.6
Indium: 4.0
Safe Alloy X X X X 0 Originally made for toy soldier casting. Principal uses are in proof casting cavities (threads, dies, molds, blind holes) (E10); duplicate patterns in foundry matchplate making (F6); supporting workpieces while machining (B5); spray coating wood patterns, dental lab techniques (swaging jacket crowns); masks for electroplating and spray painting (E11). - 158-190 - 70-88 Shrink Initially, Grows to .0000" in 1 Hour Maximum .0025" Per Inch .341 5400 9 9000 300 4.27% Bismuth: 42.5
Lead: 37.7
Tin: 11.3
Cadmium: 8.5
Matrix Alloy X No X 0 No Originated by GE for anchoring punches in dies (A15); is used also to anchor: Non-moving parts in machinery, hold down bolts in concrete floors, locator parts in tooling docks (A1). Used in split jaw chucks, jigs, fixtures (B5); metal forming dies, form blocks, joggle jaws (D6); repairing broken dies (A15); filling blow holes in casting. - 217-440 - 103-227 Rapid Initial Growth For 15 Hours Maximum .0061" Per Inch .343 13,000 19 16,000 300 2.57% Bismuth: 48.0
Lead: 28.5
Tin: 14.5
Antimony: 9.0
Cast Alloy X X X X 0 Parallels TRU in its end uses also is preferred by some for electroforming mandrels, lost wax pattern dies due to greater dimensional accuracy; holding jet turbine engine blades for machining. - 281-338 - 138-170 Maximum Shrinkage Only -.0001" Per Inch .296 8000 22 15,000 500 7.77% Bismuth: 40.00
Tin: 60.00


Home casting any metal that requires heating to it to a point that would to melt most lead alloys is extremely unsafe. Moisture is extremely hazardous to the process, and if moisture is introduced while casting occurs, the mold will explode, scattering molten metal in many directions.

Over the years CS Alloys has developed a group of “low melt alloys.” “Low melt alloys” are metal alloys that have melting temperatures that range between 117º F. and 440º F. Some of the melting temperatures for alloys within the family of metals that we have developed require less than the boiling temperature of water. This has had a significant impact on safety, and has made it possible for casting to occur at home on your kitchen table if you wish it to. That is because casting with Cerro Alloys is just as safe as boiling water.

Some alloys melt at a temperature that is too low to maintain a permanent casting. Cerrobend® and Cerrosafe® are excellent choices for casting parts. Cerrobend® is a popular solution for many due to its specific melting point. Alloys with higher melting points are usually stronger than those with lower melting points. Quenching the mold with water right after pouring is the best way to promote strength, but this is not always possible or practical. Such molds would need to be constructed from metal themselves and that type of mold would not likely be found in a home kitchen or workshop.

Depending on the shape of the part that you wish to cast, it is essential to choose the right mold that is made from the proper materials and in the proper method. A mold will need to be rigid enough to make the part strong and must also pull away from the casting when it is complete without causing any damage to the casting or to the mold itself.

The other choice is to use more flexible molds. Some are made from various plastic compounds, others from rubber or from silicone. In this case, a pattern is made and the mold material starts out liquid. Some rubber molds are set by baking them, which means that the pattern will need to be withstand a great deal of heat while the mold is curing. Dimensionally stable compounds are the best choice for mods. One example of such a compound is the type of rubber compound that a dentist used – they do not even need to be baked. The higher price may be discouraging to many though, and the materials also need to include a backing that is made from a hard setting plaster or plastic. When using this type of mold, you need to account for shrinkage.

You will not need to invest in expensive equipment in order to start casting with Cerro Alloys. All you need to begin is a hot plate, a ladle or a spoon, a double-boiler and a thermometer. After that you will need your mold and the right Cerro Alloy for the job and you’ll be ready to begin!

CS Alloys and/or this website is not affilliated in any way with Cerrobend, Cerrotru, Cerroshield, Cerrolow, Cerrosafe and these brands neither endorse nor sponsor any of the products and/or services that we provide. Our use of these brands are intended only to give examples of specific products that our products and/or serivces can help. These brands are registered trademarks of their respective owners.


Alloy Melt Range Yield Temp
Low 117 117-117 117
Low 136 136-136 136
Low 140 134-144 140
Low 147 142-149 147
Bend 158 158-158 158
Safe 165 160-190 165
Low 174 174-174 174
Shield 203 203-203 203
Base 255 255-255 255
Tru 281 281-281 281
Cast 302 281-338 302

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