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


Low melt alloys or Fusible Alloys are alloys that are made up of Bismuth, Lead, Tin, Cadmium, and Indium. Low melt alloys can expand up to 3.3% when solidifying from a liquid to a solid depending on the product. This expansion allows these alloys to precisely conform to any intricate details when molded.

CS Alloys is a modern facility with new equipment that enables us to offer our customers the most up to date and current methods of producing low melt alloys.

CS Alloys is proud to offer over 100 different low melt alloys; and can produce customer specific items to meet specific customer needs. Our products have a temperature melting range between 100 to 483 degrees Fahrenheit. We produce Low Melt items in various forms: Cakes, Extruded Bar, Wire, and Ingots.

Our manufacturing facilities are right here in America (North Carolina) and we ship our products worldwide. We are proud to help create jobs for Americans.

Directions for bending thin walled tubing with CS Alloys

  1. Make sure that tubing is fully annealed.
  2. Clean interior of tube with pull-through to remove any scale or foreign matter.
  3. Tightly plug one end of tube with wood or rubber plug.
  4. Fill tube with a light grade oil, preferably S.A.E. 10.
  5. Pour oil from tubing leaving a small amount in the bottom of the tube. Careful attention to oiling is necessary to prevent the CS Alloys “tinning” the tube.
  6. Fill tube with CS Alloys from an iron ladle or a welded stainless steel container suspended in boiling water or hot water jacketed stainless steel tank, allowing the alloy to run down the side of the tube in order to avoid air pockets. Small tubes (1/4” dia. or less) should be placed in boiling water while being filled.
  7. Lower loaded tube immediately into a cold circulating water quenching tank and leave for sufficient time for tube and filler to attain room temperature throughout (About 15 minutes for 1” diameter tubing, 20 minutes for 1-1/2” diameter tubing, etc.).
  8. After proper quenching, re-warm loaded tubes to about body temperature.
  9. Remove plug from tube.
  10. Bend loaded tube with a slow uniform pressure over a forming block or in a regular bending machine.
  11. Immerse bent tube in boiling water tank (stainless steel preferred) and allow CS Alloys to run out (Do not use torch). Tilt and shake tube as necessary to remove alloy as completely as possible.
  12. Plunge unloaded tube, while still hot, in cold water for two minutes to solidify and small drops of CS Alloys retained in the oil film.
  13. Flush tube with a cold grease solvent to remove oil film and any solid particles of CS Alloys. Additional cleaning may be done with a tight fitting pull-through.

Important: Satisfactory results depend entirely on rapid quenching and thorough cooling, re-warming before bending, and using a slow uniform pressure during the forming operation.

(Rust-less iron or stainless steel are recommended for tank construction. Plain steel will rust when in constant contact with boiling water and steam. Copper, aluminum and galvanized iron tanks will contaminate the alloy).

The approximate weight of CS Alloys per foot of tubing for various inside diameters is as follows:

  • 1/4” - .22 lbs.
  • 3/8” - .47 lbs.
  • 1/2” - .83 lbs.
  • 5/8” – 1.29 lbs.
  • 3/4” – 1.83 lbs.
  • 7/8” – 2.50 lbs.
  • 1” – 3.25 lbs.
  • 1-1/8” – 4.16 lbs.
  • 1-1/4” – 5.13 lbs.
  • 1-1/2” – 7.39 lbs.
  • 1-3/4” – 10.07 lbs.
  • 2” – 13.16 lbs.

(CS Alloys weigh .34 lbs. per cubic inch)

Do not clean tubes by pickling or any wet process, as retention of acid salts will interfere with development of a continuous oil film and increase tendency for CS Alloys to stick to tube wall.

Modern motor oils contain detergents which tend to act as flux. Straight run mineral oils, containing no detergents, are recommended. Cities Service Co’s Amples-P2 has been found satisfactory. Silicone DC-7 is excellent.

An CS Alloys remaining in tube after following direction may be removed by blowing out with steam; dissolving in dilute Sulphuric or Hydrochloric Acid or Caustic Soda solution (start with 10% solution at 200 degrees F).

Additional information on removing residual particles of CS Alloys is available on request.

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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