IS 320 covers brass rods and bars for general engineering — machining, forging, and fabrication. Three main grades: 63/37 (alpha-beta brass for hot working), 70/30 (alpha brass for cold working), and 76/22/2 (naval brass with tin for seawater resistance).
Specification for brass rods, bars, and sections covering grades, tempers, dimensions, and mechanical properties for general engineering applications.
Key Values
63/37 tensile (M)Min 340 MPa
70/30 tensile (M)Min 310 MPa
76/22/2 (naval) tensile (M)Min 370 MPa
Practical Notes
! 63/37 brass is best for hot forging (fittings, valve bodies). 70/30 for cold working (springs, deep drawing).
! Naval brass (76/22/2) has 1-2% tin — the tin prevents dezincification in seawater.
! For machine screw products on automatic lathes, use free-cutting brass (IS 319) not IS 320.
! Brass rods with surface cracks or drawing marks should be rejected — they cause failures during machining.