Gunmetal Bars, Rods & Castings

Product Overview

Gunmetal is a time-tested copper-based alloy primarily composed of copper, tin, and zinc, with small additions of lead in certain grades to enhance machinability. Gunmetal Bars, Rods & Castings supplied by R V Metal Corporation are engineered for applications demanding excellent corrosion resistance, pressure tightness, dimensional stability, and long service life under fluid handling and mechanical loads. Known for its superior performance in water, steam, oil, and mildly corrosive environments, gunmetal remains a preferred material for critical components where reliability is non-negotiable.

Our gunmetal products are manufactured in compliance with international standards such as ASTM, EN, and IS specifications, ensuring consistent chemical composition, mechanical properties, and casting integrity. Gunmetal bars and rods offer uniform grain structure suitable for precision machining, while gunmetal castings provide excellent soundness and pressure-holding capability for complex shapes. These products are widely used in valves, pumps, bushings, bearings, marine fittings, plumbing hardware, and industrial fluid-control systems where resistance to dezincification and wear is essential.

R V Metal Corporation supplies gunmetal in a wide range of sizes, grades, and forms to meet OEM, EPC, and maintenance requirements across industries such as marine, power generation, oil & gas, water treatment, and heavy engineering. With strict quality control, traceability, and technical support, our gunmetal bars, rods, and castings deliver dependable performance in demanding service conditions while supporting efficient machining and long-term operational reliability.

Technical Specifications

Specification Parameter	Details
Product Forms	Bars, Rods, Solid Castings, Hollow Castings, Bushes, Custom Machined Components
Manufacturing Process	Continuous Casting, Sand Casting, Centrifugal Casting, Hot Extrusion, Precision Machining
Typical Alloy System	Copper–Tin–Zinc (Cu–Sn–Zn) with controlled Lead (Pb) where required
Standard Grades	ASTM B62 C83600, ASTM B584 C84400, EN 1982 CC491K / CC492K, IS 318 Gr. LTB2 / LTB4
Available Shapes	Round, Square, Hexagonal, Rectangular, Hollow Cylinders, Custom Profiles
Size Range – Bars & Rods	Diameter: 10 mm to 300 mm (larger sizes on request)
Size Range – Castings	Up to 1000 mm OD depending on casting method and design
Standard Lengths	3000 mm, 4000 mm, 6000 mm or Cut-to-Length as per requirement
Supply Condition	As-Cast, Rough Machined, Fully Machined, Stress Relieved (on request)
Density (Typical)	8.7 – 8.9 g/cm³ (depending on grade)
Tensile Strength (Typical)	200 – 350 MPa (grade and condition dependent)
Hardness	65 – 100 HB (Brinell), depending on alloy and heat treatment
Pressure Tightness	Excellent, suitable for valves, pumps, and fluid handling systems
Corrosion Resistance	Very good resistance to water, steam, mild acids, and marine environments
Machinability	Good to Excellent (enhanced in leaded grades)
Operating Temperature Range	-50°C to +250°C (application dependent)
Surface Finish	As-Cast, Turned, Ground, Polished (as specified)
Dimensional Tolerances	As per ASTM / EN / IS standards or customer drawing
Testing & Inspection	Chemical Analysis, Mechanical Testing, Hydrostatic Testing (castings), NDT on request
Certification	Mill Test Certificate (EN 10204 3.1), Third-Party Inspection on request
Typical Applications	Valves, Pump Bodies, Bearings, Bushes, Gears, Marine Hardware, Steam Fittings

Chemical Composition

Element	ASTM B62 / B584 C83600 (%)	ASTM B584 C84400 (%)	EN 1982 CC491K (%)	EN 1982 CC492K (%)	IS 318 LTB2 / LTB4 (%)
Copper (Cu)	83.0 – 87.0	80.0 – 83.0	85.0 – 88.0	82.0 – 86.0	85.0 – 88.0
Tin (Sn)	4.0 – 6.0	4.0 – 6.0	4.0 – 6.0	5.0 – 7.0	4.0 – 6.0
Zinc (Zn)	2.0 – 5.0	2.0 – 5.0	2.0 – 5.0	2.0 – 4.0	2.0 – 5.0
Lead (Pb)	4.0 – 6.0	6.0 – 8.0	4.0 – 6.0	5.0 – 7.0	4.0 – 7.0
Nickel (Ni)	≤ 1.0	≤ 1.0	≤ 1.0	≤ 1.0	≤ 1.0
Iron (Fe)	≤ 0.3	≤ 0.3	≤ 0.3	≤ 0.3	≤ 0.3
Antimony (Sb)	≤ 0.2	≤ 0.2	≤ 0.2	≤ 0.2	≤ 0.2
Phosphorus (P)	≤ 0.1	≤ 0.1	≤ 0.1	≤ 0.1	≤ 0.1
Other Impurities	≤ 0.2 (Total)	≤ 0.2 (Total)	≤ 0.2 (Total)	≤ 0.2 (Total)	≤ 0.2 (Total)

UNS Codes & Grades

UNS Code	ASTM / SAE Designation	EN / DIN Equivalent	IS Equivalent	Common Trade Name	Typical Product Form	Key Characteristics
C83600	ASTM B62 / B584	EN 1982 CC491K (CuSn5Zn5Pb5)	IS 318 LTB2	Leaded Gunmetal	Castings, Bars, Rods	Excellent machinability, pressure-tight, widely used for valves & fittings
C84400	ASTM B584	EN 1982 CC492K (CuSn7Zn4Pb7)	IS 318 LTB4	High-Lead Gunmetal	Castings	Superior machinability, moderate strength, ideal for intricate cast components
C90300	ASTM B505	EN 1982 CC480K (CuSn8)	IS 318 LTB1	Tin Bronze / Semi-Gunmetal	Continuous Cast Bars, Rods	High wear resistance, lower lead, good bearing properties
C90500	ASTM B505	EN 1982 CC483K (CuSn10)	IS 318 LTB3	High Tin Bronze	Bars, Rods, Bushes	High strength, excellent corrosion & fatigue resistance
C90700	ASTM B505	EN 1982 CC485K (CuSn11Pb2)	IS 318 LTB5	Bearing Bronze	Bars, Bearings, Bushes	Excellent load capacity, controlled lead for lubrication
C92200	ASTM B505	EN 1982 CC490K (CuSn7Zn4Pb6)	IS 318 LTB6	Leaded Tin Bronze	Bars, Rods, Bushings	Balanced strength & machinability, good anti-seizure properties
C92300	ASTM B505	EN 1982 CC493K	—	Heavy Duty Gunmetal	Castings	High pressure & wear resistance, marine & pump components

Mechanical, Physical & Fabrication Properties

Property Category	Property	Gunmetal Bars & Rods (Continuous Cast)	Gunmetal Castings (Sand / Centrifugal)	Engineering Remarks
Mechanical Properties	Tensile Strength	220 – 300 MPa	180 – 250 MPa	Bars outperform castings due to refined grain structure
	Yield Strength (0.2%)	120 – 170 MPa	90 – 140 MPa	Not normally design-critical; pressure design uses tensile values
	Elongation	10 – 18 %	8 – 15 %	Lower elongation indicates brittle or porous casting
	Hardness	65 – 90 HB	60 – 85 HB	Increases with tin & lead content
	Compressive Strength	600 – 800 MPa	550 – 750 MPa	Why gunmetal excels in valve seats & bearings
Physical Properties	Density	8.7 – 8.9 g/cm³		Used for accurate theoretical weight calculations
	Melting Range	850 – 950 °C		Wide range due to Sn, Zn & Pb variations
	Thermal Conductivity	50 – 65 W/m·K		Lower than pure copper, sufficient for fluid systems
	Electrical Conductivity	12 – 15 % IACS		Not intended for electrical applications
Fabrication & Machining	Machinability	Excellent (80 – 90%)	Very Good (70 – 85%)	Lead acts as internal lubricant
	Castability	—	Excellent	Preferred for complex valve bodies & housings
	Weldability	Poor – Not Recommended		High risk of hot cracking & lead segregation
	Brazing / Soldering	Good		Requires proper flux and temperature control
	Formability	Limited	Not Applicable	Gunmetal is not a cold-forming alloy
	Typical Machining Allowance	+1.5 to 3.0 mm	+2.0 to 5.0 mm	Depends on casting method & section thickness

Common Names & International Identifiers

Region / Standard System	Common Trade Name	Standard / Specification	Grade / Designation	Typical Product Form	Industry Usage Note
India / UK	Gunmetal	IS 318	LGB1, LGB2, LGB4	Castings, Bars	Most common valve & pump alloy in India
United Kingdom	Gunmetal	BS 1400	LG2	Castings	Equivalent to IS LGB2, widely exported
United Kingdom	Leaded Gunmetal	BS 1400	LG4	Castings	Higher lead, superior machinability
Europe (EN)	Gunmetal Bronze	EN 1982	CC491K (CuSn5Zn5Pb5)	Castings	Modern EN replacement for LG2
Europe (EN)	Leaded Tin Bronze	EN 1982	CC493K	Castings	Used where enhanced machinability is required
USA (ASTM)	Gunmetal Bronze	ASTM B62	C83600	Castings	Standard US valve & fitting bronze
USA (ASTM)	Leaded Red Brass	ASTM B62 / B584	C84400	Castings	Sometimes confused with gunmetal — not identical
Germany (DIN)	Rotguss	DIN 1705	RG5	Castings	DIN equivalent of LG2 / C83600
ISO	Tin Bronze with Lead	ISO 1338	CuSn5Zn5Pb5	Castings	International harmonized designation
Trade / Foundry	Valve Bronze	—	—	Castings	Non-standard commercial naming — composition must be verified

Standards & International Equivalents

Country / Region	Standard	Grade / Designation	UNS / EN Equivalent	Typical Composition (Indicative)	Common Product Forms	Remarks / Industry Notes
India	IS 318	LGB1	—	Cu-Sn-Zn (Low Pb)	Bars, Rods, Castings	Low lead gunmetal for general engineering
India	IS 318	LGB2	EN CC491K / UNS C83600	CuSn5Zn5Pb5	Bars, Rods, Castings	Most widely used valve & pump gunmetal in India
India	IS 318	LGB4	EN CC493K	Cu-Sn-Zn-High Pb	Bars, Rods, Castings	Higher lead for superior machinability
United Kingdom	BS 1400	LG2	EN CC491K / UNS C83600	CuSn5Zn5Pb5	Castings	Direct equivalent of IS LGB2
United Kingdom	BS 1400	LG4	EN CC493K	High lead gunmetal	Castings	Used where machinability > pressure strength
Europe	EN 1982	CC491K	UNS C83600	CuSn5Zn5Pb5	Castings	Modern EN gunmetal grade
Europe	EN 1982	CC493K	—	CuSn7Zn4Pb7	Castings	Higher lead EN gunmetal variant
USA	ASTM B62	C83600	EN CC491K / BS LG2	85Cu–5Sn–5Zn–5Pb	Castings	Standard US valve bronze (gunmetal)
USA	ASTM B584	C84400	—	High Pb red brass	Castings	Often confused with gunmetal – not identical
Germany	DIN 1705	RG5	EN CC491K / UNS C83600	CuSn5Zn5Pb5	Castings	DIN gunmetal equivalent
International	ISO 1338	CuSn5Zn5Pb5	EN CC491K	Cu-Sn-Zn-Pb	Castings	Globally harmonized designation

Applications

Industry / Sector	Application	Typical Product Form	Preferred Gunmetal Grade	Key Performance Requirement	Why Gunmetal is Used
Valves & Flow Control	Gate valves, globe valves, check valves, valve bodies	Castings, Machined Rods	LGB2 / LG2 / CC491K	Pressure resistance, corrosion resistance	Excellent strength, leak resistance, long service life
Pumps & Fluid Handling	Pump casings, impellers, bushings	Castings	LGB2 / LGB4	Wear resistance, machinability	Handles water, oils & mild chemicals reliably
Marine & Offshore	Seawater valves, pipe fittings, pump parts	Castings, Bars	LG2 / CC491K	Seawater corrosion resistance	Performs better than brass in marine conditions
Plumbing & Sanitary	Faucet bodies, plumbing fittings	Castings	LGB1 / Low-Lead Grades	Low lead content, corrosion resistance	Safe for water contact when low-lead grades are used
Power Plants	Steam fittings, condensate system components	Castings, Rods	LGB2 / LG2	Thermal stability, pressure handling	Stable under temperature & pressure variations
Sugar & Process Industries	Valve parts, pump components	Castings	LGB2 / LGB4	Corrosion & wear resistance	Handles slurry, water & mild chemicals
Oil & Gas (Non-Sour)	Valve bodies, bushings, fittings	Castings, Rods	LGB2 / LG2	Dimensional stability, pressure sealing	Reliable sealing & machinability
General Engineering	Gears, bearings, wear plates	Bars, Rods	LGB4	Machinability, wear resistance	High lead improves machining performance
Railways	Brake components, bushings	Castings, Rods	LGB2	Strength, vibration resistance	Durable under cyclic loading
Defense & Shipbuilding	Seawater system components, mechanical parts	Castings	LG2 / CC491K	Reliability in harsh environments	Proven alloy for mission-critical use

Common Gunmetal Forms & Dimensions Chart

Common Gunmetal Forms & Dimensions (Bars, Rods & Castings)

Product Form	Typical Supply Type	Standard Size Range (mm)	Standard Length	Notes
Round Bars / Rods	Continuous Cast / Extruded / Drawn	Ø 10 to Ø 300 (larger on request)	1 m / 2 m / 3 m / 6 m	Machining stock available for bearing & valve components
Square Bars	Continuous Cast	10×10 to 150×150	1 m / 2 m / 3 m	Preferred for heavy machining & structural blocks
Hexagonal Bars	Extruded / Continuous Cast	AF 10 to AF 80	1 m / 2 m / 3 m	Ideal for fittings, fasteners, turned parts
Flat Bars	Rolled / Sawn from Cast Slab	Width 20 to 300, Thickness 3 to 50	1 m / 2 m / 3 m	Corner radii / edge chamfer as per drawing
Plates / Blocks	Sawn from Cast Slab / Plate	Thickness 10 to 150, Width/Length as required	Cut-to-size	For wear plates, seal plates, pump components
Hollow Bars / Bush Castings	Centrifugal Cast / Static Cast	OD 40 to 400, ID 20 to 300	Cut-to-length	Higher yield for bushings (less machining wastage)
Custom Castings	Sand / Shell / Centrifugal (as applicable)	As per pattern / drawing	As required	Heat treatment, NDT, and machining possible on request

Note (Theoretical Weight): Weight values below are theoretical and calculated using a typical gunmetal density of 8.80 g/cm³. Actual weight can vary by exact alloy chemistry, casting method, porosity, and machining allowance.

Theoretical Weight Charts (Gunmetal) – kg/m

Formulas (kg/m):

Round: (0.7854 × D² × ρ) / 1000
Square: (A² × ρ) / 1000
Hex (Across Flats): (0.6495 × AF² × ρ) / 1000
Flat: (W × T × ρ) / 1000

Where D, A, AF, W, T are in mm and ρ is density in g/cm³ (used: 8.80 g/cm³).

Round Bars / Rods – Weight per Meter

Diameter (mm)	Theoretical Weight (kg/m)
10	0.691
12	0.995
16	1.769
20	2.765
25	4.320
30	6.221
35	8.467
40	11.058
45	13.996
50	17.279
60	24.883
75	38.879
100	69.115

Square Bars – Weight per Meter

Side (mm)	Theoretical Weight (kg/m)
10	0.880
12	1.267
16	2.253
20	3.520
25	5.500
30	7.920
40	14.080
50	22.000

Hexagonal Bars (Across Flats) – Weight per Meter

Across Flats (mm)	Theoretical Weight (kg/m)
10	0.572
12	0.823
14	1.120
17	1.652
19	2.063
22	2.766
24	3.292
27	4.165
30	5.716
32	6.508
36	8.230
41	10.675

Flat Bars – Weight per Meter

Width (mm)	Thickness (mm)	Theoretical Weight (kg/m)
20	3	0.528
25	3	0.660
25	6	1.320
30	5	1.320
40	5	1.760
50	6	2.640
50	10	4.400
60	8	4.224
80	10	8.800
100	10	11.000

Important: If you are machining bushings/bearings, don’t buy “exact size” bars. Specify machining allowance (oversize) and straightness requirement—otherwise you’ll waste material, time, and tools.

Gunmetal Bars, Rods & Castings