Copper Tungsten and Tungsten Carbide Copper
(CW55, CW60, CW65, CW70E, CW75, CW80)
DWD Tungsten Metals’ copper tungsten alloys are commonly used in EDM electrodes and other electrical and electrical/thermal applications. They are also used for facing and inserts for flash and butt welding dies, projection welding electrodes, seam welding bearing inserts and facing for electro-forming and electro-forging dies.
Although they are somewhat more difficult to machine, tungsten carbide copper materials provide high mechanical properties and excellent resistance to erosion. They are commonly used in oil devices to protect the contact from oxidation.
To learn more about which copper tungsten alloy is best for your application, contact a DWD Metals professional.
Note: Our CW70E,CW75 and CW80 materials are readily available in various stocked sizes of rods and flat bars. Please see our updated parts document for information.
| Material | Density | Conductivity | Hardness |
|---|---|---|---|
| CW55 | 12.5 | 55 | 79 B |
| CW68 | 13.93 | 52 | 88 B |
| CW70 | 14.18 | 52 | 88 B |
| CW70E | 13.93 | 52 | 88 B |
| CW75 | 14.7 | 48 | 94 B |
| CW78 | 15.12 | 46 | 96 B |
| CW80 | 15.56 | 44 | 98 B |
Copper Tungsten Machining
You don’t have to sacrifice quality for machinability. Tungsten composites are extremely strong and durable (typical hardness ranges from 79-109 RB), yet very easy to work with. While they machine much like gray cast iron, tungsten composite’s low-thermal expansion and resistance to breakage and chipping allow you to achieve very close tolerances and hold on to fine finishes. Coolants are optional, reducing your processing costs and, in most cases, your carbide tools will work well with our tungsten composite materials.
Turning
Positive rake tooling is suggested. Seco triangle inserts TPG432 or TPG431 grade 883.
Boring
No rake or positive rake tooling is suggested. Seco CPMT grade 883.
Roughing
Cutting depth of .030” to .125” and .008” to .015” feed, at 200 to 300 SFM.
Copper Tungsten and Tungsten Carbide Copper
.010” to .015”cutting depth and .004” to .010” feed at 250 to 400 SFM.
Tapping
Use high-speed steel, two flute plug spiral point taps. A light tapping fluid is recommended or vegetable oil mist. OSG Sossner premium Exotap is suggested.
Drilling
Carbide tooling is suggested. Increased clearance angles and automatic feeds are often used to avoid binding and seizing. Carbide drills will give a better tool life.
Grinding
Use aluminum oxide or silicon carbide wheels of medium hardness.
Milling
Premium uncoated end mills with a regular spiral made from micrograin carbide, such as SGS. Insert cutters-use square multi-edge or single edge cutters, such as Kennametal grade KC730. Also can use positive rake octagon cutters, such as Seco grade 883.
Roughing
Feeds of .007” to .015” per tooth at speeds of 200 to 400 SFM.
Finishing
Feeds of .003” to .010” per tooth at speeds of 300 to 700 SFM.
Sawing or Cutting
When sawing, use a bi-metal blade; blade pitch should be relative to the thickness of the material. Coarse blades can be run at low speeds, and finer blades run at higher speeds. Coolant can be used. Material can also be cut using high-speed abrasive cutoff wheels.
| MTTM | Nominal Composition % Weight | Rockwell Hardness | Electrical Conductivity % IACS | Ultimate Tensile Strength PSI | Cross Breaking Strength PSI | Density g/cc | Typical Resistance Welding Applications |
|---|---|---|---|---|---|---|---|
| CW55 | 55% Tungsten 45% Copper | 79 B | 55 | 63,000 | 110,000 | 12.50 | Flash and butt welding die inserts requiring high electrical and thermal conductivity. Electrode facings for the welding of stainless steel. |
| CW68 | 68% Tungsten 32% Copper | 88 B | 52 | 75,000 | 130,000 | 13.93 | Flash and butt welding die inserts requiring high electrical and thermal conductivity. Electrode facings for the welding of stainless steel. |
| CW70E | 68% Tungsten 32% Copper | 88 B | 52 | 75,000 | 130,000 | 13.93 | Flash and butt welding die inserts requiring high electrical and thermal conductivity. Electrode facings for the welding of stainless steel. |
| CW70 | 70% Tungsten 30% Copper | 90 B | 50 | 85,000 | 140,000 | 14.18 | Light duty projection welding dies where weld pressures are medium to light. |
| CW75 | 75% Tungsten 25% Copper | 94 B | 48 | 90,000 | 150,000 | 14.70 | Used for facing and inserts for flash and butt welding dies, projection welding electrodes, seam welding bearing inserts, facings for electro-forming and electro-forging dies. Often used for EDM electrodes for greater wear ratios. |
| CW78 | 78% Tungsten 22% Copper | 96 B | 46 | 94,000 | 160,000 | 15.12 | Used where a slightly harder material is required for the same applications as CW75. |
| CW80 | 80% Tungsten 20% Copper | 98 B | 44 | 96,000 | 170,000 | 15.56 | Heavy duty projection welding electrodes, die facing for electro-forming and electro-forging, also facings for upsetting of rivets & studs. |
| SW50 | 50% Tungsten 50% Silver | 70 B | 65 | 13.4 | Used for arcing contacts and plates, arc runners, and current carrying members | ||
| SW65 | 65% Tungsten 35% Silver | 87 B | 53 | 14.5 | Used for arcing contacts and plates, arc runners, and current carrying members | ||
| SW74 | 74% Tungsten 26% Silver | 90 B | 47 | 15.5 | Used for arcing contacts and plates, arc runners, and current carrying members |
