291 Gr I

IS 291 Gr I is commonly referred to as a naval brass and issued typically in a wide range of marine and subsea Applications. This brass alloy offers superior strength and corrosion resistance and offers good property retention at cryogenic temperatures. With excellent hot formability and very good corrosion resistance.

Chemical Composition

Elements Min (%) Max (%)
Cu 61.00 64.00
Pb 0.20
Sn 1.00 1.50
Fe 0.10
Total Others 0.20
Zn Remainder

Mechanical properties according to IS 291 Gr I (as per temper HB)

Range (mm) UTS Min
(MPa)
UTS Max
(MPa)
PS Min
(MPa)
Elongation Min
(%)
Hardness Min
(HRB)
Hardness Max
(HRB)
Round (Dia) 1.5 12.5 390 18
12.5 50 380 18
50 75 345 18
Hex (A/F) 3 12.5 390 18
12.5 50 380 18
50 65 345 18
Square (A/F) 3 12.5 390 18
12.5 50 380 18
50 60 345 18
Rectangle Thickness 3 12.5 390 18
12.5 50 380 18

PHYSICAL PROPERTIES
Melting Points – Liquidus °F 1650
Melting Points – Solidus °F 1630
Density lb/cu in. at 68°F 0.304
Specific Gravity 8.41
Electrical Conductivity % IACS at 68°F 26
Thermal Conductivity Btu/Sq ft/ft hr/°F at 68°F 67
Coefficient of Thermal Expansion 68–572 × 10⁻⁶ per °F (68–572°F) 11.8
Specific Heat Capacity Btu/lb/°F at 68°F 0.09
Modulus of Elasticity in Tension ksi 15000
Modulus of Rigidity ksi 5600
FABRICATION PROPERTIES
Technique Suitability
Capacity for Being Cold Worked Fair
Hot Worked Excellent
Machinability Rating 30%
Forgeability Rating 90%
Silver Alloy Brazing Excellent
Soft Soldering Excellent
Oxyacetylene Welding Good

Typical Uses

Fasteners

Fasteners

Industrial

Industrial

Marine

Marine