Bronze Gravity Die Casting – Precision Permanent Mould Bronze Castings from India
Price: US$ 13.90 / Kilogram
Bronze Gravity Die Casting – Pump Impeller, Valve Body, Flanges, Pipe Fittings | Conex Casting India
Bronze gravity die casting is a precision metalworking process in which molten bronze alloy is poured under gravitational force into permanent steel or cast iron moulds to produce components of superior dimensional accuracy, mechanical integrity, and corrosion resistance. Conex Casting, a leading manufacturer and exporter based in Mumbai, India, supplies bronze gravity die castings to marine OEMs, pump manufacturers, oil and gas equipment companies, power utilities, EPC contractors, and industrial valve producers worldwide. Bronze’s unmatched combination of seawater corrosion resistance, load-bearing capacity, anti-galling properties, and non-sparking characteristics makes gravity die casting the preferred production route for high-reliability bronze components in critical service environments.
Product Overview
What is Bronze Gravity Die Casting?
Bronze gravity die casting – also known as bronze permanent mould casting, chill casting, or tilt-pour bronze casting – uses reusable metal dies made from hot-work tool steel (H13) or spheroidal graphite iron (GGG-70). The die is coated with a refractory wash, preheated to 200–350°C, and filled by gravity or controlled tilt-pour to produce components ranging from 100 g to 30 kg per cycle. The permanent mould provides faster solidification than sand casting, refining the microstructure and producing finer tin-bronze eutectoid distribution, improved leaded bronze anti-friction properties, and higher density in aluminium bronze castings – all critical for valves, bearings, pump bodies, and marine fittings.
Bronze Alloy Families for Gravity Die Casting
Bronze is a copper alloy in which the principal alloying element is not zinc. The commercially significant bronze families used in gravity die casting include: tin bronze (Cu-Sn), leaded tin bronze (Cu-Sn-Pb, for bearings), aluminium bronze (Cu-Al, high strength and corrosion resistance), silicon bronze (Cu-Si, weldable), manganese bronze (Cu-Zn-Mn-Al, high strength), and nickel aluminium bronze (Cu-Al-Ni-Fe, for marine pumps and valves). Each family occupies a distinct application niche defined by its unique combination of strength, wear resistance, corrosion resistance, and machinability.
Dimensional Capability and Tolerances
Bronze gravity die castings are manufactured in weights from 100 g to 30 kg per casting. As-cast dimensional tolerances of ±0.3–±0.9 mm are achievable, improving to ±0.05–±0.1 mm after CNC machining. Surface roughness of Ra 3.2–6.3 µm as-cast is standard. Minimum wall thickness of 3 mm for tin bronze and 4 mm for aluminium bronze can be maintained. Draft angles of 0.5–2° are incorporated in the mould design to facilitate ejection without distortion. Mould life exceeds 20,000–35,000 shots for most bronze alloys, making the process economical for medium-to-high volume production from 500 to 200,000 pieces per year.
Mechanical Properties and Load-Bearing Capability
Bronze gravity die castings exhibit tensile strengths ranging from 180 MPa (leaded tin bronze for bearing applications) to 700 MPa (nickel aluminium bronze for high-pressure pump components). Brinell hardness ranges from 60 HB to 250 HB. Anti-galling properties are inherent in leaded tin bronze due to the lubricating action of the lead phase. Fatigue resistance of aluminium bronze and nickel aluminium bronze approaches that of medium carbon steel, making these alloys suitable for propeller shafting, high-cycle valve stems, and structural marine components operating under dynamic loading.
Corrosion Resistance in Aggressive Environments
Bronze alloys are among the most corrosion-resistant engineering metals. Tin bronze and phosphor bronze resist corrosion in freshwater, steam, and many industrial acids. Aluminium bronze forms a passive aluminium oxide film providing outstanding resistance to seawater, chlorinated water, sulphuric acid, and oxidising conditions. Nickel aluminium bronze (NAB) is the standard alloy for Royal Navy, NATO, and offshore industry pump and valve components, providing dezincification immunity, resistance to crevice corrosion, and immunity to stress corrosion cracking in seawater. Silicon bronze resists sulphur-containing compounds and marine atmospheres, making it the preferred architectural bronze for coastal installations.
Anti-Friction and Bearing Properties
Leaded tin bronze (LG2, LG4) and leaded bronze (C93200, CC495K) are the standard bearing and bushing alloys for rotating machinery. The dispersed lead phase provides boundary lubrication, conformability to shaft irregularities, and embedability for abrasive particles. These properties make leaded tin bronze gravity die castings the material of choice for plain bearings, thrust washers, worm gear wheels, pump impeller wear rings, and valve stem bushings in pumps, compressors, hydraulic machinery, and electrical generator bearings where oil-film lubrication may be intermittent.
Non-Sparking and Non-Magnetic Properties
Aluminium bronze and tin bronze are non-sparking (non-incendive) and inherently non-magnetic. These properties are mandatory for tools and components used in explosive atmospheres (ATEX Zone 1 and Zone 2) such as oil refineries, LNG terminals, chemical plants, offshore platforms, and grain handling facilities. Bronze gravity die castings are used for valve handwheels, spanner flats, impact wrenches, and structural components in ATEX-classified areas where iron and steel components pose ignition hazards.
Electrical and Thermal Conductivity
Tin bronze exhibits electrical conductivity of 10–15% IACS and thermal conductivity of 60–80 W/m·K. Phosphor bronze with phosphorus deoxidation has conductivity of 15–20% IACS. Silicon bronze offers 7% IACS. These moderate conductivity values, combined with excellent spring properties and corrosion resistance, make phosphor bronze the standard material for electrical connector springs, contact fingers, flexible busbars, and current-carrying leaf springs in switchgear, relays, and metering equipment.
Comparison with Other Casting Processes
Compared to sand casting, bronze gravity die casting delivers better surface finish (Ra 3.2 vs. 12.5 µm), tighter dimensional tolerances (±0.3 vs. ±1.5 mm), and superior mechanical properties due to faster directional solidification in the permanent mould. Compared to investment casting, gravity die casting offers lower tooling cost, faster cycle times, and higher weight capacity, making it the preferred process for bronze valve bodies, pump casings, and bearing housings in the 100 g–30 kg weight range at production volumes from 500 to 200,000 pieces per year.
Material Grades – Bronze Alloys for Gravity Die Casting
IS 318 Grade 1 – Tin Bronze (Gun Metal / G1 Bronze)
IS 318 Grade 1 (Cu 85–87%, Sn 9–11%, Zn 1–3%, Pb 1–3%) is the most widely specified tin bronze casting alloy in Indian industry, known commercially as “Gun Metal” or “G1 Bronze”. It offers excellent pressure tightness, good machinability, high corrosion resistance in steam, freshwater, and seawater, and good anti-friction properties. Applications include valve bodies, pump casings and impellers, pipe fittings, steam flanges, and general engineering castings for water, oil, and gas service. International equivalents: CC491K (EN), C90500 (ASTM), CuSn10Zn2 (ISO), CAC402 (JIS).
LG2 Bronze – Leaded Tin Bronze (Leaded Gunmetal)
LG2 (Cu 85%, Sn 5%, Zn 5%, Pb 5% per BS 1400 LG2) is a leaded gunmetal with excellent pressure tightness, castability, machinability, and anti-galling properties. It is the standard general-purpose bronze casting alloy for valve bodies, pump casings, bearing housings, and fittings in the UK and Commonwealth markets. International equivalents: CC490K (EN), C83600 (ASTM/UNS), CAC406 (JIS).
LG4 Bronze – High-Lead Tin Bronze for Bearings
LG4 (Cu 84%, Sn 7%, Pb 7%, Zn 2% per BS 1400 LG4) is formulated for bearing applications where high lead content provides maximum boundary lubrication. Used for heavy-duty plain bearings, thrust pads, worm wheel rims, and slow-speed/high-load bearing applications in steel mills, press machinery, mining equipment, and hydraulic turbines. Equivalent to CC495K (EN), C93200 (ASTM – SAE 660), CuSn7ZnPb (ISO).
PB1 – Phosphor Bronze (Deoxidised Tin Bronze)
PB1 (Cu 89–91%, Sn 9–11%, P 0.03–0.25%) is a phosphor-deoxidised tin bronze with high purity, excellent pressure tightness, superior strength, and good spring properties. Phosphor bronzes exhibit higher fatigue strength, better resistance to impingement attack, and superior mechanical properties at elevated temperatures. Used for pump impellers, bearing rings, high-pressure valve seats, electrical connector springs, and flexible busbar components. Equivalents: CC480K (EN), C90700 (ASTM), CuSn10P (ISO), CAC502A (JIS).
AB1 – Aluminium Bronze (Cu-Al Binary)
AB1 (Cu 88–92%, Al 8–10% per BS 1400 AB1) is a single-phase alpha aluminium bronze of high strength, good toughness, and excellent corrosion resistance. The aluminium content forms a stable Al2O3 surface film providing resistance to seawater, acids, and high-temperature oxidation. Used for marine hardware, bearing races, valve stems, pump impellers, and corrosion-resistant structural components. Equivalents: CC330G (EN), C95200 (ASTM), CuAl9 (ISO).
AB2 – High-Strength Aluminium Bronze (Cu-Al-Fe)
AB2 (Cu 83–87%, Al 9–11%, Fe 2–5%, Mn 0.5–2.5% per BS 1400 AB2) is an alpha-beta two-phase aluminium bronze with tensile strength up to 620 MPa and outstanding seawater corrosion resistance. The iron addition refines the grain structure and provides good fatigue resistance. Used for ship propellers, pump casings for seawater service, high-pressure hydraulic fittings, valve bodies for offshore applications, and gear blanks. Equivalents: CC332G (EN), C95400 (ASTM), CuAl10Fe3 (ISO).
NAB – Nickel Aluminium Bronze (Cu-Al-Ni-Fe)
Nickel Aluminium Bronze (Cu 78–82%, Al 8–9.5%, Ni 4–6%, Fe 3–5%, Mn 0.5–2%) is the premium bronze alloy for critical marine, offshore, and military applications. NAB provides tensile strength of 630–750 MPa, superior resistance to impingement corrosion, cavitation erosion, and biofouling in seawater, and immunity to stress corrosion cracking. Heat treatment (solution anneal at 900°C + air cool) homogenises the microstructure for consistent mechanical properties. Standardised as BS 1400 AB2, DEF STAN 02-834, ASTM B148 C95800, EN CC333G. Used for naval pump casings, offshore valve bodies, ship propellers, and subsea structural components.
CC491K / EN 1982 – European Tin Bronze Standard
CC491K (Cu remainder, Sn 9.0–11.0%, Zn 2.0%, Pb 2.0%) is the European standard tin bronze for sand and permanent mould castings per EN 1982. Mechanical properties: UTS 270 MPa min, elongation 13% min, hardness 75 HB. Standard alloy for pressure-retaining valve castings, pump bodies, and hydraulic fittings supplied to European customers. Pressure equipment (PED) compliance documentation is provided with shipments.
C93200 (SAE 660) – ASTM Standard Bearing Bronze
C93200 (Cu 81–85%, Sn 6.3–7.5%, Pb 6.0–8.0%, Zn 2.0–4.0%) is the most widely used bearing bronze in North America, specified in ASTM B584 and SAE J461. The combination of tin and lead makes C93200 the benchmark bearing alloy for journal bearings, bushings, thrust washers, and worm wheels in industrial machinery. Gravity die casting produces superior mechanical properties compared to sand casting due to faster solidification and finer microstructure.
C87300 / C87600 – Silicon Bronze
Silicon bronze (Cu 94–96%, Si 3.0–5.0%) offers high strength, excellent weldability, and outstanding atmospheric and seawater corrosion resistance without lead. Used for architectural bronze castings, marine fittings, pump components, and electrical conduit fittings where weldability and lead-free compliance are required. C87300 meets NSF 61 potable water standards for water treatment equipment.
Key Features of Bronze Gravity Die Castings
- Price: US$ 13.90 per kilogram (ex-works Mumbai, India)
- Weight range: 100 g to 30 kg per casting
- Dimensional tolerance: ±0.3 mm (as-cast), ±0.05 mm (after CNC machining)
- Surface roughness: Ra 3.2–6.3 µm as-cast
- Minimum wall thickness: 3 mm (tin bronze), 4 mm (aluminium bronze)
- Tensile strength: 180–750 MPa depending on alloy grade
- Full alloy range: IS 318, LG2, LG4, PB1, AB1, AB2, NAB, CC491K, C93200
- Secondary machining, threading, and surface finishing in-house
- ISO 9001:2015 certified manufacturing facility
- Material Test Certificates per EN 10204 3.1 on request
Unmatched Corrosion Resistance
Bronze gravity die castings are specified wherever iron, steel, or aluminium would fail due to corrosion. Tin bronze withstands fresh water, steam, oil, and most dilute acids. Aluminium bronze resists seawater, sulphuric acid, and high-temperature oxidation up to 400°C. Nickel aluminium bronze (NAB) is immune to dezincification, resistant to impingement and cavitation corrosion, and is the primary structural alloy in Royal Navy and offshore industry pumping systems. These properties are intrinsic to the alloy and persist throughout the service life of the component regardless of wear.
High Mechanical Performance Across Temperature
Tin bronze and aluminium bronze gravity die castings retain useful mechanical properties from cryogenic temperatures (-196°C for liquid nitrogen service) to elevated temperatures (+250°C for tin bronze, +400°C for aluminium bronze). This makes them suitable for cryogenic valve components in LNG terminals, high-temperature steam fittings in power generation, and process equipment operating across wide thermal cycles. Unlike steels, copper alloys do not exhibit brittle fracture at low temperatures, which is critical for safety-critical cryogenic applications.
Anti-Galling and Bearing Performance
Leaded tin bronze (LG2, LG4, C93200) is the industry standard for bearing applications. The self-lubricating lead phase provides boundary lubrication during oil film breakdown, protects the mating steel shaft from scoring, and embeds abrasive contaminants. Gravity die casting produces finer, more uniformly distributed lead particles than sand casting, resulting in superior bearing performance: lower coefficient of friction, higher PV (pressure x velocity) limit, and extended bearing life in worm gear, pump, and hydraulic machinery applications.
Non-Sparking Safety Compliance
Aluminium bronze and tin bronze gravity die castings are certified non-sparking per EN 13463-1 and ATEX Directive 2014/34/EU. Components are used in ATEX Zone 1 and Zone 2 classified areas including oil refineries, gas compression stations, LNG facilities, pharmaceutical plants, and coal mining. Non-sparking bronze hardware reduces ignition risk of flammable gases and vapours, satisfying mandatory safety requirements in hazardous area equipment standards.
Marine Grade Availability and Class Society Certification
Conex Casting supplies bronze castings conforming to Lloyd’s Register, Bureau Veritas, DNV-GL, ABS, and ClassNK requirements for marine classification. Nickel aluminium bronze (NAB) castings meet DEF STAN 02-834, MIL-B-24480, and ASTM B148 C95800 for naval applications. Certificates of conformance and class society certificates are available. Third-party inspection by SGS, Bureau Veritas, or Intertek can be arranged for marine and offshore shipments.
Full Secondary Machining and Testing Capability
Post-cast operations include CNC turning, milling, drilling, and threading (BSP, NPT, metric); pressure testing to 100 bar hydraulic for valve and pump bodies; surface finishing including electroless nickel, tin plating, chrome plating, and powder coating; and non-destructive testing (UT, DPI, MPI) for high-integrity structural and pressure-retaining components. This integrated capability allows Conex Casting to deliver fully machined, tested, and certified bronze castings ready for assembly.
Technical Specifications
| Parameter | Specification |
|---|---|
| Base Material | Copper-Tin, Copper-Aluminium, Copper-Silicon, or Copper-Nickel Alloy (Bronze) |
| Casting Process | Gravity Die Casting / Permanent Mould Casting / Tilt-Pour Casting |
| Weight Range | 100 g – 30 kg per casting |
| Dimensional Tolerance (as-cast) | ±0.3 mm – ±0.9 mm |
| Dimensional Tolerance (machined) | ±0.05 mm – ±0.1 mm |
| Surface Roughness (as-cast) | Ra 3.2 – 6.3 µm |
| Minimum Wall Thickness | 3 mm (tin bronze); 4 mm (aluminium bronze) |
| Pouring Temperature | 1000 – 1150°C (alloy dependent) |
| Mould Preheat Temperature | 200 – 350°C |
| Tensile Strength Range | 180 – 750 MPa (alloy dependent) |
| Hardness Range | 60 – 250 HB (alloy dependent) |
| Elongation | 3 – 30% (alloy dependent) |
| Electrical Conductivity | 7 – 20% IACS (alloy dependent) |
| Thermal Conductivity | 30 – 80 W/m·K |
| Density | 7.6 – 8.9 g/cm³ (alloy dependent) |
| Mould Life | 20,000 – 35,000 shots |
| Production Volume | 500 – 200,000 pieces/year |
| Unit Price | US$ 13.90 / kg |
Bronze Alloy Grade and International Equivalent Table
| Indian (IS / BS) | European (EN / CC) | ASTM / UNS (USA) | ISO | JIS (Japan) | Key Characteristic |
|---|---|---|---|---|---|
| IS 318 Gr 1 (Gun Metal G1) | CC491K / EN 1982 | C90500 | CuSn10Zn2 | CAC402 | General purpose tin bronze, pressure tight |
| LG2 (BS 1400) | CC490K | C83600 | CuSn5Zn5Pb5 | CAC406 | Leaded gunmetal, valves, pump bodies |
| LG4 (BS 1400) | CC495K | C93200 (SAE 660) | CuSn7ZnPb | CAC602 | Bearing bronze, high lead, anti-friction |
| PB1 (BS 1400) | CC480K | C90700 | CuSn10P | CAC502A | Phosphor bronze, high strength, springs |
| PB2 (BS 1400) | CC482K | C90300 | CuSn8 | CAC502B | Phosphor bronze, bearing and gears |
| AB1 (BS 1400) | CC330G | C95200 | CuAl9 | CAC702 | Aluminium bronze, alpha phase, marine |
| AB2 (BS 1400) | CC332G | C95400 | CuAl10Fe3 | CAC703 | Al-bronze, alpha-beta, high strength |
| NAB (DEF STAN 02-834) | CC333G | C95800 | CuAl10Ni5Fe4 | CAC704 | Nickel Al-bronze, marine/offshore grade |
| – | CC212E | C87300 | CuSi3Mn | – | Silicon bronze, lead-free, weldable |
| – | – | C86300 | CuZn25Al5Mn4Fe3 | – | Manganese bronze, high strength |
Product Types and Variants
Conex Casting supplies bronze gravity die castings in the following product categories, all available with CNC machining, threading, and surface finishing:
- Valve Bodies and Trim – Gate valve bodies, globe valve bodies, ball valve bodies, check valve bodies, safety valve bodies, butterfly valve discs, valve seats and stem bushings (DN15 to DN300)
- Pump Components – Pump casings, impellers, wear rings, pump covers, bearing housings, seal carriers, stuffing box covers in tin bronze, aluminium bronze, and NAB for seawater, freshwater, and chemical service
- Plain Bearings and Bushings – Journal bearings, thrust washers, worm wheel blanks, crosshead guides, self-lubricating bearing rings (LG2, LG4, C93200, SAE 660)
- Marine Hardware – Sea cocks, through-hull fittings, propeller shaft brackets, stern tube bushings, deck hardware, shipboard electrical junction boxes, cleats, and fairleads
- Electrical Hardware – Earthing terminals, bus-bar end caps, connector housings, switchgear brackets, flexible busbar connectors, current transformer brackets
- Pipe Fittings and Flanges – Flanged elbows, tees, reducers, blind flanges, steam flanges, hydraulic fittings, instrumentation manifolds (ANSI, BS, DIN)
- Industrial Gears and Sprockets – Worm wheel rims and rings, helical gear blanks, sprocket hubs, gear guards in high-lead tin bronze for dry or minimal lubrication duty
Applications by Industry
| Industry Sector | Typical Bronze Gravity Die Cast Components |
|---|---|
| Marine and Shipbuilding | Propeller shaft bearings, sea-cock valve bodies, through-hull fittings, pump casings, deck hardware, shipboard electrical housings (NAB, AB2, LG2) |
| Oil and Gas | Valve bodies for sour service, instrument manifolds, non-sparking fittings for ATEX zones, flange bodies, gauge valve bodies (AB2, NAB, LG2) |
| Power Generation | Condenser tube plate bushings, turbine bearing rings, feed pump components, governor valve bodies, steam valve trim (PB1, LG2, CC491K) |
| Water Treatment | Pump impellers, valve bodies, strainer housings, backflow preventer bodies, chlorination valve components (tin bronze, silicon bronze) |
| Electrical and Power | Earthing hardware, switchgear brackets, connector housings, bus-bar end fittings, current-carrying components (PB1, CC491K) |
| Pump Manufacturing | Pump casings, impellers, wear rings, bearing housings for water, chemical, and marine service (LG2, AB2, NAB) |
| Chemical Processing | Valve bodies for acid service, pump components, non-sparking fittings, ATEX hardware (AB1, AB2, silicon bronze) |
| Mining and Heavy Industry | Worm wheel rims, journal bearings, crusher bearings, conveyor shaft bushings (LG4, C93200, SAE 660) |
Typical Parts Produced — Bronze Gravity Die Casting
Bronze gravity die casting serves some of the most demanding engineering environments — marine, subsea, power generation, heavy pumping, and chemical processing. The part families below represent the full range of components regularly cast in bronze alloys (tin bronze, leaded gunmetal, aluminium bronze, phosphor bronze, silicon bronze) using permanent mould methods.
| Part / Component | Common Alloy Grade | Indicative Size / Weight | Key Industry |
|---|---|---|---|
| Pump Impellers (centrifugal, axial) | LG2 (IS 318 G1), AB2, CC491K | Ø80–Ø600 mm | 0.3–35 kg | Marine, Water Treatment, Power Generation |
| Pump Casings & Volute Housings | LG2, AB1, AB2 | DN50–DN300 | 1.5–60 kg | Marine, Process Industry, Power Plants |
| Valve Bodies (globe, gate, check, butterfly) | LG2, LG4, PB1, CC491K | DN15–DN300 | 0.3–80 kg | Marine, Oil & Gas, Power, Water Treatment |
| Sea-Cock & Through-Hull Valve Bodies | LG2, AB2 (ASTM B148 C95400) | DN20–DN150 | 0.5–25 kg | Marine, Shipbuilding, Offshore |
| Propeller Shaft Bearings & Stern Tubes | LG2, NAB (IS 318 AB2), C93200 | Ø30–Ø300 mm bore | 0.3–40 kg | Marine, Naval, Offshore |
| Worm Wheel Rims & Gear Blanks | LG4, C93200 (SAE 660), PB1 | Ø60–Ø600 mm | 0.4–80 kg | Mining, Crane & Hoist, General Engineering |
| Journal Bearings & Bushings | C93200 (SAE 660), LG4, PB1 | Ø20–Ø300 mm | 0.05–20 kg | Mining, Heavy Industry, Printing Machinery |
| Turbine Bearing Rings & Thrust Plates | PB1 (CC483K), LG2, CC491K | Ø80–Ø500 mm | 0.5–50 kg | Power Generation, Hydro Turbines |
| Propellers (small craft & workboat) | NAB (AB2, C95400) | Ø200–Ø800 mm | 2–120 kg | Marine, Defence, Dredging |
| Non-Sparking Tool Castings & ATEX Fittings | AB1, AB2 (Aluminium Bronze) | 0.1–10 kg | Oil & Gas, Chemical Processing, Mining |
| Condenser Tube Plates & End Covers | LG2, NAB, CC491K | 200–1200 mm plate | 2–150 kg | Power Generation, Desalination, Shipbuilding |
| Earthing Hardware (clamps, bars, connectors) | PB1 (CC483K), CC491K | 10–240 mm² | 0.05–0.8 kg | Electrical Utilities, Switchgear OEMs |
| Instrument Manifolds & Gauge Valve Bodies | LG2, CC491K | DN6–DN25 | 0.1–1.5 kg | Oil & Gas, Chemical, Power Generation |
| Strainer Bodies & Backflow Preventer Bodies | LG2, AB1, Silicon Bronze | DN25–DN200 | 0.5–20 kg | Water Treatment, Plumbing, Municipal Utilities |
| Crusher Bearings & Conveyor Shaft Bushings | LG4, C93200, SAE 660 | Ø40–Ø400 mm | 0.2–60 kg | Mining, Aggregate, Cement, Heavy Industry |
| Hydraulic Cylinder End Caps & Rod Bushings | LG2, AB1, C93200 | Ø30–Ø200 mm | 0.1–15 kg | Construction Equipment, Off-Highway, Hydraulics |
| Steam Valve Trim (discs, seats, stems) | PB1, LG2, CC491K | DN15–DN100 | 0.05–5 kg | Power Plants, Process Industry, Steam Systems |
| Chemical Pump Components (wear rings, covers) | AB1, AB2, Silicon Bronze (C87300) | DN40–DN250 | 0.3–30 kg | Chemical Processing, Pharma, Fertilisers |
Parts Produced by Industry Sector — Quick Reference
| Industry | Representative Parts | Required Properties / Standards |
|---|---|---|
| Marine & Shipbuilding | Propeller shaft bearings, sea-cock valve bodies, through-hull fittings, pump casings & impellers, propellers, deck hardware, stern tube bushings, shipboard lighting housings | Seawater corrosion resistance, de-aluminification resistance, DNV/Lloyd’s/BV/ABS class approval |
| Power Generation | Condenser tube plates, turbine bearing rings, feed pump impellers, steam valve trim, governor valve bodies, thrust bearing pads | High temperature strength (to 260°C), steam erosion resistance, ASME/BS EN compliance |
| Oil, Gas & Petrochemical | Non-sparking ATEX fittings, sour service valve bodies, instrument manifolds, flange bodies, gauge valve bodies, subsea connector components | NACE MR0175/ISO 15156 (H2S), ATEX/IECEx for hazardous areas, non-magnetic |
| Water Treatment & Utilities | Pump impellers & casings, backflow preventer bodies, strainer housings, check valve bodies, metering pump components, chlorination valve bodies | Chlorine and biocide resistance, WRAS/NSF-61 approval, low-lead casting |
| Pump Manufacturing | Pump casings (centrifugal, axial, mixed flow), impellers, wear rings, bearing housings, shaft sleeves, mechanical seal glands | Cavitation resistance, hydraulic efficiency, IS 5084/BS EN 1982 material compliance |
| Electrical & Power Utilities | Earthing clamps, neutral link bodies, switchgear brackets, high-current bus-bar connectors, instrument transformer brackets, cable grounding systems | High conductivity (PB1/CC483K), corrosion resistance, IEC 62561/BS EN compliance |
| Mining & Heavy Industry | Worm wheel rims, journal bearings, crusher bearings, conveyor shaft bushings, bucket-wheel bearings, ball mill trunnion liners | High load capacity, anti-galling, wear resistance, oil-film lubrication compatibility |
| Chemical & Process Industry | Chemical pump casings, reactor agitator hubs, valve bodies for acid/alkali service, non-sparking hand tools, process pipe flanges | Chemical resistance (AB1/AB2/Silicon Bronze), ATEX rating, ASME B16.34 compliance |
Manufacturing Process
The bronze gravity die casting process at Conex Casting follows a rigorous structured sequence: (1) Mould Design and Simulation – 3D CAD modelling, solidification simulation (Magmasoft or ProCAST), CNC machining of H13 tool steel or GGG-70 cast iron dies with controlled draft angles, venting channels, and water cooling circuits; (2) Alloy Preparation and Verification – Spectrometric OES analysis of all incoming copper ingot, return metal, and alloying additions to confirm chemistry to IS 318, LG2, CC491K, C93200, C95800, or client-specified grade before charging the induction furnace; (3) Mould Preparation – Application of colloidal graphite or zirconia-based refractory mould wash, preheat to 200–350°C, and installation of sand cores or metal cores as required for complex internal geometries in pump bodies and valve bonnets; (4) Melting and Degassing – Induction furnace melting with phosphorus or zinc deoxidation where specified; nitrogen or argon rotary degassing to minimise hydrogen porosity in tin bronze and aluminium bronze; (5) Pouring – Controlled tilt-pour or ladle pour at 1000–1150°C (alloy dependent); pouring temperature verified by immersion pyrometry; (6) Solidification and Ejection – Controlled mould cooling; ejection at appropriate temperature to avoid hot tearing; (7) Fettling, Shot Blasting, and Inspection – Gate and riser removal by sawing or grinding; vibratory shot-blast cleaning; dimensional CMM inspection; spectrometric verification; pressure testing; NDT; (8) Machining and Finishing – CNC turning, milling, drilling, threading, deburring; surface treatment as specified; (9) Packaging – VCI-protected export packing in wooden crates or fibre cartons suitable for sea freight to all global ports.
Quality Standards and Certifications
| Standard / Certification | Scope |
|---|---|
| ISO 9001:2015 | Quality Management System – design, manufacturing, inspection |
| IS 318 | Indian Standard for tin bronze and leaded tin bronze castings |
| EN 1982 | European standard for copper alloy castings (CC491K, CC490K, CC495K, CC480K) |
| ASTM B584 / B148 | ASTM standard for copper alloy sand and permanent mould castings (C93200, C95800) |
| BS 1400 | British Standard for bronze castings (LG2, LG4, PB1, AB1, AB2) |
| DEF STAN 02-834 | UK Defence Standard for nickel aluminium bronze (NAB) castings |
| Lloyd’s Register / DNV-GL / Bureau Veritas / ABS | Marine classification society approval for shipboard components |
| RoHS 2011/65/EU | Lead-free compliance for silicon bronze and aluminium bronze grades |
| ATEX 2014/34/EU | Non-sparking certification for aluminium bronze and tin bronze components |
| EN 10204 3.1 / 2.2 | Material test certificates with spectrometric analysis and mechanical test results |
| PED 2014/68/EU | Pressure Equipment Directive compliance documentation for valve and pump castings |
| NSF 61 / NSF 372 | Potable water compliance for silicon bronze and lead-free tin bronze grades |
Why Choose Conex Casting for Bronze Gravity Die Castings?
- 40+ years of bronze casting expertise – Deep metallurgical knowledge of tin bronze, leaded bronze, aluminium bronze, phosphor bronze, and nickel aluminium bronze
- In-house mould shop – CNC machined moulds in H13 tool steel designed with solidification simulation
- Full secondary machining – CNC turning, milling, drilling, threading, and assembly under one roof
- Multi-standard alloy compliance – IS, BS, EN, ASTM, JIS grade availability with spectrometric certificates
- Marine and offshore grade capability – NAB, AB2, LG2 with class society certification (LR, BV, DNV-GL, ABS)
- Competitive pricing – US$ 13.90/kg, ex-works Mumbai; DDP pricing available for major trade lanes
- Export experience – Shipments to 40+ countries with full export documentation, LC handling, and third-party inspection
- Non-sparking ATEX grade availability – AB1, AB2, tin bronze with ATEX compliance documentation
- Pressure testing – Hydraulic testing to 100 bar for valve and pump castings on in-house test bench
Equivalent Terms
| Language | Equivalent Terms for Bronze Gravity Die Casting |
|---|---|
| Spanish | Fundición en molde permanente de bronce, Colada por gravedad de bronce, Fundición coquilla bronce |
| French | Coulée en coquille par gravité en bronze, Moulage en coquille bronze, Fonderie bronze coquille |
| Russian | Литьё бронзы в кокиль, Гравитационное кокильное литьё бронзы, Постоянная форма бронзовое литьё |
| Portuguese | Fundição em molde permanente de bronze, Fundição por gravidade em bronze, Coquilha bronze fundição |
| Italian | Fusione in conchiglia per gravità in bronzo, Colata per gravità in bronzo, Fusione in stampo permanente bronzo |
Frequently Asked Questions (FAQ)
Q1. What bronze alloy grades are available for gravity die casting?
We supply all major bronze grades including IS 318 Grade 1 (Gun Metal G1), LG2, LG4, PB1 (phosphor bronze), AB1 and AB2 (aluminium bronze), NAB (nickel aluminium bronze per ASTM C95800 / DEF STAN 02-834), C93200 (SAE 660 bearing bronze), CC491K (EN 1982), and silicon bronze C87300. Custom alloy compositions are available on request with spectrometric verification.
Q2. What is the price of bronze gravity die castings?
The indicative price for bronze gravity die castings is US$ 13.90 per kilogram, ex-works Mumbai, India. Final pricing depends on alloy grade (NAB and aluminium bronze command a premium over tin bronze), part complexity, machining requirements, surface finish, quantity, and delivery terms. Formal quotations are issued within 24 hours.
Q3. Can you supply NAB castings with marine classification society certificates?
Yes. We supply nickel aluminium bronze (NAB) gravity die castings conforming to ASTM B148 C95800 and DEF STAN 02-834 with certificates from Lloyd’s Register, Bureau Veritas, DNV-GL, ABS, and ClassNK. Third-party inspection and witnessing by your nominated inspection agency can be arranged at our foundry.
Q4. Are your bronze castings suitable for ATEX Zone 1 hazardous areas?
Aluminium bronze (AB1, AB2) and tin bronze castings are inherently non-sparking and are supplied with ATEX compliance documentation per EN 13463-1 and ATEX Directive 2014/34/EU. These materials are mandatory for valve handwheels, fittings, and structural components in Zone 1 and Zone 2 classified areas in oil, gas, and chemical plants.
Q5. What is the difference between LG2 and C83600 bronze?
LG2 (BS 1400) and C83600 (ASTM/UNS) are essentially equivalent leaded gunmetal alloys with composition Cu 83–86%, Sn 4–6%, Zn 4–6%, Pb 4–6%. LG2 is the British Standard designation and C83600 (also known as “Ounce Metal”) is the ASTM designation. Both are used for valve bodies, pump casings, and general-purpose pressure castings. We can cast to either specification and provide the corresponding material certificate.
Q6. What is the minimum order quantity for bronze gravity die castings?
Minimum order quantity for repeat production on existing tooling is 500 pieces. New tooling development has no minimum piece count, though tooling investment (USD 1,200–12,000 depending on complexity) is required. Expedited first-article samples in 3–4 weeks and production delivery in 2–3 weeks on established tooling.
Q7. Can bronze gravity die castings be pressure tested?
Yes. Valve bodies, pump casings, and pressure-retaining castings can be hydraulically tested to 100 bar on our in-house pressure test bench. Pneumatic leak testing and helium leak testing are also available. Test certificates are issued for each batch, with individual piece marking where required by the quality plan.
Q8. What secondary machining is available on bronze castings?
In-house CNC machining includes turning, milling, drilling, reaming, and thread tapping in BSP, NPT, BSPT, and metric standards. Surface finishing options include electroless nickel, electrolytic nickel, chrome plating, tin plating, and powder coating. All machining is performed to the client’s drawing and tolerances with CMM verification and first-article inspection reports.
Q9. How do you ensure alloy chemistry compliance?
Every heat of bronze is analysed by Optical Emission Spectrometry (OES) before pouring. Results are compared against the specified alloy standard (IS 318, EN 1982, ASTM B584, BS 1400, etc.) and material is rejected if any element falls outside the specified range. Mill Test Certificates per EN 10204 3.1 (with test results and signatory) or 2.2 (conformance certificate) are issued as part of the standard documentation package.
Q10. Do you supply bronze gravity die castings to the oil and gas sector?
Yes. We supply valve bodies, instrument manifolds, gauge valve bodies, and non-sparking fittings in LG2, AB2, NAB, and PB1 to oil and gas equipment manufacturers and EPC contractors for onshore and offshore projects. Materials conform to NACE MR0175/ISO 15156 compatibility for sour service where applicable, and full material traceability documentation is maintained for PED and ASME compliance.
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Request a Quote
Contact Conex Casting for a formal quotation on bronze gravity die castings. Send your technical drawings (DXF, STEP, IGES, PDF), material specification, quantity requirements, and required delivery terms to sales@conex-casting.com or call +91-22 43449300/23. Quotations are issued within 24 hours. Our technical team provides alloy selection guidance, DFM review, marine classification support, and application engineering at no additional charge.