LG2 Bronze Casting 85-5-5-5

LG2 bronze (also designated 85-5-5-5 or “Red Brass”) is a leaded gunmetal alloy casting containing approximately 85% copper, 5% tin, 5% zinc, and 5% lead, conforming to BS 1400 LG2, ASTM C83600, DIN 1705 G-CuSn5ZnPb, and EN 1982 CC491K standards. This quaternary copper alloy is one of the most widely cast copper materials globally, valued for its excellent castability, good pressure tightness, moderate mechanical properties, and versatility across general engineering, valve, bearing, pump, and plumbing applications. Brass & Copper Parts manufactures LG2 bronze castings in sand cast, centrifugal cast, and continuous cast forms for industrial, marine, and infrastructure customers worldwide.

Product Overview

LG2 bronze (85-5-5-5) achieves a balanced combination of mechanical strength, corrosion resistance, and manufacturing characteristics that have made it the default general-purpose bronze casting alloy for over a century. The 5% zinc content improves castability and reduces porosity; the 5% lead provides pressure tightness by filling micro-shrinkage voids during solidification and aids machinability by producing short, brittle chips during CNC cutting operations. LG2 bronze castings achieve tensile strengths of 240–280 MPa, yield strength of 100–120 MPa, and elongation of 20–30%, making them ductile and reliable for pressure-retaining components. Brass & Copper Parts produces LG2 castings in component weights from 0.05 kg to 300 kg, with full material certification to BS, ASTM, DIN, and EN standards.

Key Features

• Excellent castability and pressure tightness – Lead content fills micro-shrinkage, producing leak-free castings
• Good machinability – Lead phase enables chip-breaking and reduces tool wear in CNC machining
• Good corrosion resistance – Performs well in freshwater, steam, and mild industrial chemical environments
• Good bearing properties – Suitable for lightly loaded bearing and bushing applications
• Widely specified standard alloy – Globally recognized under BS 1400 LG2, ASTM C83600, EN CC491K
• Cost-effective general purpose alloy – Lower alloy cost than phosphor bronze or aluminum bronze
• Good weldability and repairability – Can be repaired by TIG/MIG welding with matching filler

Technical Specifications

International Grade Equivalents

Product Types and Variants

LG2 Bronze Sand Castings for Valve Bodies

LG2 bronze (C83600) is the most widely used material for sand cast valve bodies including gate valves, globe valves, check valves, ball valves, and butterfly valves rated to PN10 and PN16 for water, steam, gas, and compressed air service. Sand casting produces valve bodies from 15 mm (½”) to 300 mm (12″) nominal bore, in individual casting weights from 0.1 kg to 100 kg. These castings meet BS 1400 LG2, EN 1982 CC491K, and ASTM B584 C83600 standards. Post-casting operations include CNC machining, thread cutting, lapping of valve seats, and hydrostatic pressure testing per BS EN 12266 or customer specification. Brass & Copper Parts supplies valve body castings to valve manufacturers, OEM builders, and aftermarket replacement markets globally.

LG2 Bronze Pump Castings

Pump bodies, pump volutes, impellers, wear rings, stuffing box covers, and bearing housings for water and low-pressure fluid handling pumps are commonly manufactured in LG2 bronze. The alloy’s pressure tightness ensures leak-free pump castings at rated working pressure, while its corrosion resistance in freshwater, steam condensate, and mild brine makes it suitable for a broad range of fluid service applications. LG2 bronze pump castings are produced per ASTM B584, BS 1400 LG2, and EN 1982 standards, with dimensional inspection per pump manufacturer drawings. Brass & Copper Parts produces pump castings for centrifugal, gear, and reciprocating pump OEM applications with casting weights from 0.2 kg to 200 kg per piece.

LG2 Bronze Bearing and Bushing Castings

While not as hard or wear-resistant as phosphor bronze, LG2 bronze (85-5-5-5) is widely used for lightly loaded bearings, guide bushings, flanged bushings, and bearing housings in light industrial machinery, water pump bearings, and agricultural equipment. The lead content provides self-lubricating properties under boundary lubrication conditions, reducing seizure risk in intermittent-lubrication applications. LG2 bronze bushings are produced by sand casting or centrifugal casting per ASTM B505 and DIN 1705, in bore diameters from 10 mm to 300 mm. Brass & Copper Parts machines LG2 bushings to H7 bore tolerance and supplies them as finished components ready for press-fit installation.

LG2 Bronze Sand Castings for Plumbing and Marine Hardware

General plumbing hardware including stopcocks, gate valves, compression fittings, hose connectors, and marine hardware such as through-hull fittings, seacocks, and keel bolts are traditionally manufactured in LG2 bronze due to its combination of corrosion resistance, pressure tightness, and cost-effectiveness. Marine LG2 castings conform to Lloyd’s Register, DNV, and IACS material requirements for seawater-immersed components below the waterline. Pressure ratings conform to PN10–PN16, with hydrostatic test pressure at 1.5× rated pressure. Brass & Copper Parts supplies marine hardware castings with classification society material certificates as required for vessel certification.

Centrifugal Cast LG2 Bronze Rings and Cylinders

Centrifugal casting of LG2 bronze produces rings, cylinders, and hollow blanks with dense, porosity-free microstructure suitable for subsequent machining into bushings, piston rings, cylinder liners, and bearing races. Centrifugal cast LG2 achieves better mechanical properties than static sand castings of the same alloy due to elimination of shrinkage porosity in the casting cross-section. Brass & Copper Parts produces centrifugally cast LG2 bronze in outside diameters from 50 mm to 600 mm and lengths up to 1000 mm, supplied as rough castings or machined to customer dimensions. These are used in hydraulic cylinder seal grooves, pump shaft sleeves, and marine stern tube liner applications.

LG2 Bronze Castings for Steam and Compressed Air Service

Steam trap bodies, steam valve bodies, compressed air system components, and pressure gauge bodies are frequently manufactured in LG2 bronze due to its stability at moderate temperatures (up to 200°C) and proven resistance to steam condensate corrosion. LG2 bronze maintains adequate mechanical properties and dimensional stability at steam service temperatures encountered in HVAC, food processing, and light industrial steam distribution systems. Pressure ratings for LG2 bronze steam service castings are typically PN16 (cold rating) derated per EN 1982 temperature-pressure derating tables for elevated temperature service. All steam service castings from Brass & Copper Parts are hydrostatic tested at 1.5× rated cold working pressure.

Applications by Industry

Manufacturing Process

LG2 bronze castings at Brass & Copper Parts are produced by induction melting of copper, tin, zinc, and lead in controlled ratios. The melt temperature is held at 1100–1150°C for complete dissolution of alloying elements. Pouring temperature is adjusted to 1050–1080°C depending on section thickness and mold type to optimize fluidity without excessive gas porosity. Sand molds (green sand or chemically bonded) use wooden or metal patterns that are maintained to drawing accuracy. Core boxes produce internal passages for valve seats, pump impeller eye, and through-bore cavities. After casting, components are fettled, shot blasted, spectrometrically analyzed, dimensionally inspected, machined per drawing, and hydrostatically tested at 1.5× rated pressure for all pressure-retaining castings. Full EN 10204 Type 3.1 material certificates are issued with every heat.

Quality Standards and Certifications

• BS 1400 LG2 – British standard for leaded gunmetal castings
• ASTM B584 – C83600 sand castings for general applications
• EN 1982 CC491K – European copper alloy casting standard
• DIN 1705 G-CuSn5ZnPb – German standard for leaded tin bronze
• IS 318 – Indian standard for copper alloy castings
• ISO 9001:2015 – Quality management system
• DNV / Lloyd’s / BV material approval for marine grade castings
• BS EN 12266 – Pressure testing for industrial valves

Why Choose Brass & Copper Parts

Brass & Copper Parts has been producing LG2 bronze castings for valve, pump, marine, and general engineering applications for two decades. Our LG2 production involves dedicated pattern storage with over 500 active patterns for standard valve and pump components, enabling rapid supply of repeat castings. Spectrometric analysis is performed on every melt, and hydrostatic pressure testing is standard for all valve and pump body castings. We supply LG2 castings as rough castings, semi-machined blanks, or fully machined finished components per customer drawings. Export documentation including EN 10204 3.1 certificates, packing lists, and customs documentation is prepared for each shipment to international customers in the UK, Europe, North America, Australia, and Southeast Asia.

Frequently Asked Questions

What does “85-5-5-5” mean for LG2 bronze?

“85-5-5-5” refers to the nominal composition of LG2 bronze: approximately 85% copper, 5% tin, 5% zinc, and 5% lead. This shorthand notation is widely used in foundry practice to identify the alloy. The actual compositional ranges per ASTM C83600 and BS 1400 LG2 allow ±1% variation on each element from the nominal value, with additional minor element limits for iron, nickel, antimony, and phosphorus.

Is LG2 bronze suitable for potable water applications?

Standard LG2 bronze (C83600) contains 4–6% lead and is NOT suitable for potable water or drinking water contact applications under NSF/ANSI 61, AB 1953 (California), or EU Drinking Water Directive regulations. For potable water applications, lead free alloys such as C87850 (silicon brass) or dezincification-resistant lead free brass must be specified. LG2 bronze remains widely used for industrial water, fire water, and non-potable water systems where lead content restrictions do not apply.

What is the difference between LG2 and LG4 bronze?

LG4 bronze (BS 1400 LG4, ASTM C83800) contains approximately 7–9% tin, 4–6% zinc, and 3–5% lead, compared to LG2’s 5-5-5 formula. The higher tin content in LG4 provides greater hardness and wear resistance, making LG4 more suitable for pump impellers and bushings subject to moderate wear, while LG2 is preferred for valve bodies and general castings where slightly better corrosion resistance and ductility are advantageous. Both are widely used; LG2 is more common for valve service, LG4 for pump service.

What pressure rating do LG2 bronze valve castings carry?

LG2 bronze valve castings are typically rated PN10 (10 bar) or PN16 (16 bar) at 20°C per EN 1982 / BS EN 1092. At elevated temperatures, the pressure rating is derated per published tables: at 120°C, PN16 castings are typically derated to PN12–PN14 depending on wall thickness. For steam service above 150°C, higher-grade bronzes or cast iron may be preferred. All pressure ratings should be confirmed against the applicable valve standard (EN 1074, BS 5150, etc.).

Can LG2 bronze castings be welded for repair?

Yes. LG2 bronze can be repaired by TIG (GTAW) or MIG (GMAW) welding using C83600 or C92200 matching filler wire. Pre-heat to 100–150°C is recommended for sections above 10 mm thickness. However, weld repairs on pressure-retaining valve bodies require re-testing and may not be accepted by all quality standards or classification societies without prior approval. Brass & Copper Parts provides weld repair capability for LG2 bronze castings on request, with NDT and hydrostatic re-test documentation.

What machining parameters apply to LG2 bronze?

LG2 bronze has a machinability rating of approximately 80% relative to free-cutting brass (C36000 = 100%). Recommended CNC turning parameters: cutting speed 90–120 m/min, feed 0.2–0.4 mm/rev, depth of cut 1–5 mm with carbide tooling. The lead phase provides chip-breaking characteristics enabling clean, controllable chip formation. Coolant is recommended for sustained production machining to control thermal expansion and achieve consistent dimensional accuracy.

What is the minimum order quantity for LG2 bronze sand castings?

Brass & Copper Parts accepts orders from a single prototype piece for LG2 bronze sand castings where patterns already exist. For new casting patterns (tooling), a minimum commitment of 10–20 pieces per year is typically required to justify pattern manufacture cost, which is quoted separately. Production orders for repeat components are accepted from 10 pieces upward. Standard casting lead time is 3–5 weeks from order confirmation.

Do LG2 bronze castings require heat treatment?

LG2 bronze castings do not typically require heat treatment. They are used in the as-cast condition for most applications. Stress relief annealing (600–650°C, 1 hour, furnace cool) may be specified for components with high residual stress from complex mold restraint during solidification, particularly for large valve bodies or pump casings with significant variation in section thickness. Post-machining stress relief is occasionally specified for precision components to prevent distortion during subsequent operations.

What NDT methods are applied to LG2 bronze castings?

Standard NDT for LG2 bronze pressure castings includes visual inspection and dimensional check (100%), hydrostatic pressure test at 1.5× rated working pressure (standard for all pressure-retaining castings), and dye penetrant testing (PT/FPI) for surface crack detection on request. Radiographic testing (RT) and ultrasonic testing (UT) are available for critical components or project specification requirements. All NDT is performed by qualified operators to ASNT Level II or equivalent certification.

Request a Quote

Brass & Copper Parts is a specialist LG2 bronze foundry supplying valve bodies, pump castings, marine hardware, and general engineering bronze castings worldwide. Contact our technical sales team with your drawings and requirements for competitive pricing and fast delivery.

Contact us: sales@brass-copper-parts.com | +91-22-43449300