C38500, Free cutting brass, is a significantly improved form of 60/40 brass, with excellent free cutting properties. It is used in the mass production of brass components where maximum output and longest tool life are required, and where no further cold forming after machining is required.

Chemical Composition

Elements Min (%) Max (%)
Cu 55.00 59.00
Pb 2.50 3.50
Fe 0.35
Total Others 0.50
Zn Remainder

Mechanical properties according to astm B455 (as per temper HO2)

Range (inch) UTS Min
(ksi)
UTS Max
(ksi)
PS Min
(ksi)
Elongation Min
(%)
Hardness
Hardness Min
(HRB)
Hardness Max
(HRB)
Round (Dia) 0.059 – 3 48 16 15
Hex (A/F) 0.059 – 3 48 16 15
Square (A/F) 0.059 – 3 48 16 15
Rectangle (Thickness) 0.059 – 3 48 16 15

 

 

Range (mm) UTS Min
(MPa)
UTS Max
(MPa)
PS Min
(MPa)
Elongation Min
(%)
Hardness Min
(HRB)
Hardness Max
(HRB)
Round (Dia) 1.5 75 330 110 15
Hex (A/F) 1.5 75 330 110 15
Square (A/F) 1.5 75 330 110 15
Rectangle (Thickness) 1.5 75 330 110 15

PHYSICAL PROPERTIES
Melting Point – Liquidus °F 1630
Melting Point – Solidus °F 1610
Density lb/cu in at 68°F 0.306
Specific Gravity 8.47
Electrical Conductivity %IACS at 68°F 28
Thermal Conductivity BTU/ sq ft/ ft hr/ °F at 68°F 71
Coefficient of Thermal Expansion 68–572 10⁻⁶ per °F (68 – 572°F) 11.6
Specific Heat BTU/ lb /°F at 68°F 0.09
Modulus of Elasticity in Tension ksi 14000
Modulus of Rigidity ksi 5300
FABRICATION PROPERTIES
Technique Suitability
Soldering Excellent
Brazing Good
Oxyacetylene Welding Not Recommended
Gas Shielded Arc Welding Not Recommended
Coated Metal Arc Welding Not Recommended
Spot Welding Not Recommended
Seam Welding Not Recommended
Butt Welding Fair
Capacity for Being Cold Worked Poor
Excellent
Machinability Rating 90

Typical Uses