ASME SB280 C10300 copper tube is a seamless, bright annealed product made from oxygen-free low-phosphorus copper. The grade combines very high thermal and electrical conductivity with the cleanliness and surface finish required for refrigeration, heat-transfer and electrical duty. This guide explains what C10300 is, how the four common tempers differ, and where the tube is used.
What C10300 Copper Tube Is
C10300 is a low-phosphorus oxygen-free copper. The controlled deoxidation practice leaves the metal free of oxide inclusions, which is why the grade is chosen for bright annealed tube and for parts that must be formed, bent or welded without risk of hydrogen embrittlement. Seamless tube made to ASME SB280 and ASTM B280 is produced by extrusion and cold drawing, then annealed in a controlled atmosphere to give the bright surface implied by the product name. Tube is supplied in straight lengths and coils.
Advantages of C10300 Seamless Tube
The grade offers higher temperature strength than ordinary deoxidised copper, good creep resistance at moderate temperature and strong oxidation resistance. Its conductivity, combined with the absence of oxide inclusions, suits conductor and heat-transfer duty, while the smooth bright bore keeps pressure drop low and helps maintain cleanliness in refrigeration circuits. The uniform fine grain produced by bright annealing also gives predictable forming behaviour, so bending and flaring operations repeat reliably from batch to batch.
Mechanical Properties by Temper
Four tempers cover most orders. Temper R360 is the hardest: tensile strength at least 360 MPa, yield strength at least 320 MPa, elongation about 2% and hardness at least 110 HV. Temper R290 gives tensile strength of 290 to 360 MPa, yield strength about 250 MPa, elongation around 4% and hardness of 90 to 110 HV. Temper R240 shows tensile strength of 240 to 300 MPa with yield strength around 180 MPa, elongation near 8% and hardness of 65 to 95 HV. Temper R220 is the softest condition: tensile strength of 220 to 260 MPa, yield strength of 140 MPa or less, elongation around 33% and hardness of 40 to 65 HV, which suits bending and flaring.
Physical Properties
Density is about 0.323 lb per cubic inch. Electrical resistivity at 68 °F is about 10.5 μΩ·cm, and the modulus of elasticity in tension is 17000 ksi. The mean coefficient of thermal expansion is 9.4 and the melting point is 1981 °F. These values are typical for the grade and vary little between tempers, which makes the data usable for thermal and electrical design work.
Size Range and Supply Forms
Light drawn tube is catalogued from 1/8 inch to 3 inch nominal diameter, with wall thickness from 0.030 inch to 0.105 inch, and heavier walls become available as the diameter increases. Light annealed tube for metric markets runs from 12 mm to 108 mm outside diameter in 3 m straight lengths, with weights quoted per metre, per 3 m length and per bundle, and the number of tubes per bundle falls as the diameter rises. Coils are available in small diameters where long uninterrupted runs are needed.
Equivalent Grades and Trade Code
C10300 corresponds to EN Cu-HCP and to CW021A in the TS 13388 and DIN CEN systems, and the grade carries HSN code 741110 for customs classification of copper tube. Material certificates are normally issued against the ordered specification, and tube can be supplied to ASME SB280, ASTM B280, ASTM B75 and related tube specifications depending on the end use.
Heat Treatment and Fabrication
Annealing is carried out between 700 °F and 1200 °F, and the hot working range is 1400 °F to 1600 °F. In fabrication, brazing and soft soldering are rated excellent, hot tinning and electroplating are excellent, cold forming is excellent, and gas shielded arc welding is excellent. Laser welding and resistance welding are less suitable without special procedures, and machinability is limited, so parts are normally formed rather than cut. Common processes include drawing, bending and forming, pressing and hot forging, swaging and squeezing, blanking, punching and stamping.
Applications
C10300 bright annealed tube is used for condensers and heat exchangers, refrigeration and air-conditioning circuits, bus bars and other conductive components, rectangular waveguides made to ASTM B372 and bright annealed tube supplied to ASTM B743. Its clean bore and stable conductivity also suit instrument lines and general engineering work where contamination or oxide inclusions would cause problems.
Frequently Asked Questions
Q: What is ASME SB280 C10300 copper tube?
A: It is a seamless copper tube made from oxygen-free low-phosphorus copper and supplied in the bright annealed condition, with very high thermal and electrical conductivity.
Q: How does C10300 differ from C11000?
A: C10300 is an oxygen-free low-phosphorus copper, while C11000 is electrolytic tough pitch copper; C10300 is preferred where cleanliness and welding behaviour matter.
Q: Which temper bends most easily?
A: R220 soft temper has elongation around 33% and hardness of 40 to 65 HV, so it bends and flares most easily, while R360 is the hardest condition for straight parts.
Q: What sizes are available?
A: Light drawn tube from 1/8 inch to 3 inch diameter with walls of 0.030 to 0.105 inch, and light annealed tube from 12 mm to 108 mm outside diameter in 3 m lengths.
Q: What is the HSN code for C10300 copper tube?
A: The HSN code is 741110, which covers copper tube of this type in customs classification.
Q: Where is C10300 bright annealed tube used?
A: Condensers and heat exchangers, refrigeration and air-conditioning systems, bus bars, waveguides made to ASTM B372 and bright annealed tube supplied to ASTM B743.
