Grades

OXYGEN FREE HIGH CONDUTIVITY COPPER (OFHC)

Oxygen-free high-conductivity copper is produced by directly converting carefully selected refined cathodes under strictly controlled conditions to ensure the pure, oxygen-free metal remains uncontaminated throughout the processing.

The manufacturing process of OFHC (Oxygen-Free High Conductivity) copper ensures the production of a superior-grade metal with an outstanding copper purity of 99.996%. The negligible presence of impurities allows this copper type to exhibit the true properties of pure copper to an exceptional degree. Its key characteristics include excellent ductility, outstanding electrical and thermal conductivity, high impact resistance, impressive creep resistance, ease of welding, and low volatility even under high vacuum conditions. With less than 10 parts per million of oxygen, OFHC copper remains completely free from copper oxide particles.

Lower oxygen content in oxygen free high conductivity copper has many advantages over ETP copper as shown in the following table.

Tig welding in moist atmosphere

Hydrogen Embrittlement Test

Microstructure

ELECTROLYTIC TOUGH PITCH COPPER

Chemical Composition
Material	Normal Composition	Nearest Relevant Composition Specification
		BS: 2870	ISO	JIS
Electrolytic Tough Pitch H.C. Copper
	Cu – 99.90% Min.	C 101	Cu ETP 1337	H 3100 C 1100
	Pb – 0.005% Max
	Bi – 0.001% Max
	O₂ – 0.060% Max

TYPICAL MECHANICAL PROPERTIES

Material	Temper	Tensile Strength N/mm²	Elongation % on 50 mm G.L.	Vickers Hardness VPN	ISO	JIS
Electrolytic Tough Pitch H.C. Copper	‘O	210 Min	35 Min	55 Max	Cu ETP 1337	H 3100 C 1100
	M	210 Min	35 Min	65 Max
	1/2 H	240 Min	10 Min	70 to 95
	H	290 Min	–	90 Min
‘O’b : Annealed Condition
1/2 Hv : Half Hard
Hb : Hard
* : Electric Conductivity at 20 Deg. Cel.100% IACS (For Cu ETP ‘O’ Temper)

DEOXIDIZED PHOSPHOROUS COPPER

Chemical Composition
Material	Normal Composition	Nearest Relevant Composition Specification
		BS: 2870	ISO	JIS
Phosphorous Deoxidized Copper (DONA)	Cu – 99.85% Min P – 0.013-0.050%	C 106	Cu DHP 1337	H 3100 C 1220
Material confirming to other National Specification e.g. ASTM, DIN etc. is also provided.
Available in Strips, Sheets, Plates & Circles form.

TYPICAL MECHANICAL PROPERTIES
Material	Temper	Tensile Strength N/mm²	Elongation % on 50 mm G.L.	Vickers Hardness VPN	ISO	JIS
Phosphorous Deoxidized Copper	‘O’	210 Min	35 Min	55 Max	Cu DHP 1337	H 3100 C 1220
	M	210 Min	35 Min	65 Max
	1/2 H	240 Min	10 Min	70 to 95
	H	290 Min	–	90 Min
‘O’b : Annealed Condition
1/2 Hv : Half Hard
Hb : Hard

PHOSPHORIZED LOW RESIDUAL PHOSPHORUS COPPER

CHEMICAL COMPOSITION
Material	Normal Composition	Nearest Relevant Composition Specification
		IS	ASTM	EN
Phosphorized Low Residual Phosphorous Copper	Cu – 99.90% Min. P – 0.004 – 0.012	IS :1545 : 1994	B75 C12000 / Cu-DLP	N

TYPICAL MECHANICAL PROPERTIES
Material	Temper	Tensile Strength N/mm²	Elongation % on 50 mm G.L.	Vickers Hardness VPN	Conductivity % IACS	ISO	ASTM
Phosphorized Low Residual Phosphorous Copper	‘O’	205 Min	40% Min	60 Max	90 % Min	IS : 1545 : 1994	B 75 C 12000/Cu-DLP
	Hb	245 – 325	–	80 – 100	88 % Min
	HD	315 Min	–	105 Min	88 % Min
‘O’ : Soft – Annealed Condition
Hb : Half Hard Condition
HD : Hard Condition

CADMIUM COPPER

Pure, unalloyed copper is soft, ductile, and typically contains around 0.7% impurities. Cadmium copper alloys, classified as high copper alloys, consist of approximately 98–99% copper, 0.1–1.5% cadmium, and occasionally trace amounts of other materials. The addition of cadmium enhances the material’s resistance to softening at elevated temperatures. The greater the cadmium content, the higher the heat resistance of the alloy. Notably, small amounts of cadmium do not negatively impact the thermal and electrical conductivities or the mechanical properties of cadmium copper at room temperature.

Cadmium copper applications

Trolley wire
Heating pads
Electric blanket elements
Spring contacts
Connectors
High strength transmission lines

Cadmium copper is also commonly used in soldering applications, particularly for joining components in automobile and truck radiators, as well as in semiconductor packaging operations. The UNS alloy designations for cadmium copper alloys containing approximately 1% cadmium are C16200 and C16500, while alloys with 0.1 to 0.2% cadmium are designated as C14300. Notably, there are no cast cadmium copper alloys.

The microstructure of cadmium copper resembles that of pure copper materials. It is easily formed through cold working and hot forming processes. The microstructures of worked materials exhibit equiaxed, twinned grains, which may contain oxide inclusions distributed throughout the grains.