85-5-5-5 Bronze Alloy Casting | Cu85-Sn5-Pb5-Zn5 Leaded Quaternary Bronze Castings

85-5-5-5 Bronze Alloy Casting | Cu85-Sn5-Pb5-Zn5 Leaded Quaternary Bronze Castings

The 85-5-5-5 Bronze alloy — designated by its elemental composition of 85% copper (Cu), 5% tin (Sn), 5% lead (Pb), and 5% zinc (Zn) — is a globally recognized quaternary copper-base casting alloy known under multiple international standards including ASTM C83600, BS 1400 LG2, EN 1982 CC491K, DIN Rotguss RG5, and JIS CAC406. Electrical Accessories India manufactures precision 85-5-5-5 bronze castings in sand, investment, and permanent mold processes for electrical OEMs, EPC contractors, power utilities, valve manufacturers, pump suppliers, and industrial distributors worldwide. The 85-5-5-5 composition has been the engineering standard for pressure-tight castings, valve bodies, marine fittings, and bearing bushings for over 150 years, offering an unmatched combination of machinability, corrosion resistance, and pressure integrity. Indicative price: US$ 13.90/kilogram (subject to quantity and specification).

Product Overview

The 85-5-5-5 Composition: Engineering Rationale

The 85-5-5-5 formulation represents one of the most rigorously optimized alloy compositions in copper metallurgy. The dominant copper matrix (85%) provides excellent electrical and thermal conductivity, inherent antimicrobial surface properties, corrosion resistance in atmospheric and aqueous environments, and the ductility needed for complex casting geometries. The 5% tin addition acts as the primary strengthening element, forming hard intermetallic phases (Cu3Sn, Cu6Sn5) that increase hardness and wear resistance. Lead at 5% dissolves partially in the copper matrix and partially forms discrete globular precipitates at grain boundaries, providing chip-breaking during machining and self-lubrication in bearing contacts. Zinc at 5% improves melt fluidity (reducing misrun defects), deoxidizes the melt, and marginally increases strength through solid-solution strengthening. The synergistic combination of these four elements produces an alloy with tensile strength 241–275 MPa, elongation 15–20%, Brinell hardness 60–80 HB, and machinability rating 90% relative to free-cutting brass.

Casting Process and Foundry Metallurgy

85-5-5-5 bronze is one of the most foundry-friendly copper alloys available, exhibiting good fluidity, moderate shrinkage (1.4–1.6%), and minimal hot-tearing tendency across all major casting processes: green sand (CO2, clay-bonded), no-bake (furan, alkaline phenolic), investment (lost wax), shell mold, and permanent mold. Pouring temperature range of 1050–1150°C allows standard foundry practice without specialist equipment. The alloy’s lead content suppresses die sticking in permanent mold operations, enabling extended die life. Minimum section thickness of 3 mm is routinely achievable in sand casting; investment casting enables sections to 1.5 mm with tolerances to CT5–CT6 per ISO 8062. Electrical Accessories India uses induction melting with OES analysis pre-tap and post-solidification to verify chemistry conformance to ASTM B584 / BS 1400 LG2 / EN 1982 CC491K requirements.

Pressure Tightness: The Defining Property

Pressure tightness — the absence of interconnected micro-porosity that would allow fluid leakage under pressure — is the primary engineering reason 85-5-5-5 bronze has been selected for valve bodies, pump casings, and hydraulic components for over a century. The alloy achieves this through its solidification characteristics: lead (low melting point 327°C) solidifies last, filling interdendritic spaces and eliminating shrinkage micro-porosity that plagues lead-free bronze and aluminum bronze alloys in complex casting geometries. ASTM B62 hydrostatic test protocol (300 psi / 20.7 bar for water/gas service) is routinely passed by correctly poured 85-5-5-5 castings without the hot isostatic pressing (HIP) or impregnation treatments required for competing alloys.

Corrosion Performance Across Environments

85-5-5-5 bronze castings demonstrate class-leading corrosion resistance in the widest range of service environments of any copper casting alloy: freshwater (neutral pH 6–8), seawater and brackish water, steam condensate, dilute sulfuric acid (to pH 4), organic acids (acetic, formic, oxalic), neutral chloride solutions, and atmospheric environments including marine, urban, and mildly industrial categories. The low zinc content (5%) inherently prevents dezincification corrosion — the selective removal of zinc that creates a porous copper “plug” in standard brass — making 85-5-5-5 bronze safe for use in aggressive potable water systems, groundwater service, and corrosive soil environments without special treatment or DZR-grade specification. Comparative corrosion testing shows 85-5-5-5 bronze outperforms leaded yellow brass (C85400), naval brass (C46400), and standard leaded tin bronze C90700 in seawater immersion tests of 12-month duration.

Machinability in Production Manufacturing

With machinability rated at 90% relative to free-cutting brass (C36000 / CDA 360 = 100%), 85-5-5-5 bronze is the easiest-to-machine copper casting alloy in standard use, enabling high production rates on CNC lathes, Swiss-type automatics, machining centers, and multi-spindle screw machines without costly specialist tooling or coolant additives. Lead provides chip-breaking action eliminating the long, stringy chips that characterize lead-free bronze and tin bronze alloys, which cause tool wear, tool wrap-around failures, and surface finish degradation. Tool life data shows 85-5-5-5 bronze allows tungsten carbide insert lifetimes 3–5× greater than equivalent cuts in phosphor bronze C90700 or aluminum bronze C95500, significantly reducing per-part manufacturing cost for high-volume precision components.

Bearing and Tribological Properties

85-5-5-5 bronze (particularly its lead phase) exhibits excellent tribological properties in dry, semi-lubricated, and boundary-lubricated sliding contacts against hardened steel shafts. The PV (pressure × velocity) limit for 85-5-5-5 bronze sleeve bearings is 50,000–70,000 psi·ft/min with continuous lubrication, suitable for the majority of industrial machinery, pump, and gearbox bearing applications. The alloy’s compliance (relatively low hardness 60–80 HB) allows it to embed abrasive particles from the lubricant, preventing shaft scoring — a critical advantage in equipment operating in dusty or particle-laden environments such as mining, construction, and agriculture. 85-5-5-5 bronze bearings are interchangeable with phosphor bronze bearings (C90700) in most applications at significantly lower cost due to superior machinability.

Electrical and Grounding Hardware

In electrical engineering applications, 85-5-5-5 bronze castings are specified for cable gland bodies, compression gland nuts, earth pits and earthing system hardware, neutral link housings, busbar support insulators, terminal connectors, and switchgear internals. The alloy’s non-sparking property (impact energy <0.3 J in stoichiometric hydrogen) qualifies it for use in explosive atmospheres per ATEX Directive 2014/34/EU and IECEx Scheme, making it the material of choice for cable gland bodies and earthing hardware in petrochemical plant, mining, and pharmaceutical manufacturing hazardous areas. The 15% IACS electrical conductivity supports current-carrying requirements in terminal blocks, earthing clamps, and grounding connectors rated up to 1000A continuous service.

Key Features of 85-5-5-5 Bronze Alloy Castings

• Nominal composition Cu 85% – Sn 5% – Pb 5% – Zn 5% (quaternary leaded bronze)
• Multi-standard compliant: ASTM C83600, BS 1400 LG2, EN 1982 CC491K, DIN 2.1098
• Industry-leading machinability: 90% rating relative to free-cutting brass
• Certified pressure-tight per ASTM B62 (300 psi hydrostatic test)
• Dezincification-resistant due to <6% zinc — suitable for potable water and marine service
• Non-sparking / non-magnetic — qualified for ATEX Zone 1 & 2 applications
• Available in all casting processes: sand, investment, permanent mold, centrifugal
• EN 10204 Type 3.1 MTRs with OES chemical analysis and mechanical test data

Strength and Hardness Characteristics

85-5-5-5 bronze castings exhibit tensile strength of 241–275 MPa depending on casting process and section size, with 0.2% proof stress of 110–120 MPa and Brinell hardness 60–80 HB. These properties are maintained from cryogenic temperatures (−196°C) through the maximum service temperature of 260°C without brittle fracture concerns, making the alloy suitable for liquefied gas service hardware and high-temperature steam valve applications within the specified range. Impact toughness (Charpy V-notch) of approximately 15 J at room temperature ensures resistance to vibration and shock loading in valve trim, pump impeller, and electrical hardware applications subjected to mechanical stress during operation.

Thermal Properties and Heat Dissipation

With thermal conductivity of 72 W/m·K, 85-5-5-5 bronze provides efficient heat dissipation in bearing housings, motor frame components, and electrical hardware where thermal management is a secondary design consideration. Thermal expansion coefficient (CTE) of 18 µm/m·°C (similar to most copper alloys) ensures predictable dimensional behavior in assemblies combining 85-5-5-5 bronze with steel, aluminum, or other copper alloys across operational temperature ranges. The alloy’s relatively high melting range (852–1010°C) ensures no creep or softening under the most demanding industrial process temperatures encountered in steam, thermal oil, or superheated water service.

Dimensional Accuracy and Inspection Capabilities

Electrical Accessories India maintains full CMM (coordinate measuring machine) capability for first-article inspection of 85-5-5-5 bronze castings per customer drawing tolerances. AQL 2.5 (ISO 2859-1) dimensional sampling is applied to production batches. Surface roughness measurement, pressure testing (pneumatic to 1.5× operating pressure, hydrostatic per ASTM B62), radiographic inspection (ASTM E505 Levels 1–3), and dye-penetrant inspection (ASTM E165) are available as customer-specified quality gates. All inspection records are retained for 10 years per ISO 9001:2015 requirements, supporting customer warranty and lifecycle traceability requirements.

Packaging and Corrosion Protection for Export

85-5-5-5 bronze castings are packed for export in wooden crates with VCI film wrapping, moisture-barrier polythene bags, and foam-padded separators to prevent contact damage during sea freight. Threaded bores are plugged with nylon caps; flange faces are protected with cardboard and strapping. Export markings comply with ISPM 15 (heat-treated timber) and ISO 780 (handling symbols) requirements. VCI protection maintains corrosion-free surface condition for storage up to 24 months in covered, non-condensing warehouse conditions.

Technical Specifications – 85-5-5-5 Bronze

International Standard Equivalents – 85-5-5-5 Bronze

Product Types and Variants

• Sand Castings: All sizes from 100 g to 1,000 kg; valve bodies, manifolds, pump casings, flanges
• Investment Castings: Complex precision parts, impellers, small valve internals, intricate electrical housings
• Centrifugal Castings: Cylindrical bushings, rings, bearing shells — superior dendritic structure and density
• Permanent Mold Castings: High-volume production for terminal blocks, flanges, small valve bodies
• Machined Castings: Fully CNC-machined to drawing, threaded, bored, ground to ISO 2768-m tolerance

Applications by Industry

Manufacturing Process

Electrical Accessories India produces 85-5-5-5 bronze castings from certified virgin and secondary copper, tin, lead, and zinc raw materials. Charge composition is verified by OES (optical emission spectrometry) prior to melting to confirm compliance with ASTM B584 / BS 1400 LG2 / EN 1982 CC491K compositional limits. Induction furnace melting at 1100–1150°C ensures complete dissolution and homogeneous alloy distribution. Mold preparation (green sand, no-bake furan, or investment shell) follows qualified foundry practice parameters. Pouring is conducted at controlled temperature with appropriate metallostatic head to fill all casting sections. After solidification, fettling removes gates and risers; shot blasting prepares the surface. CNC machining (where specified) is performed on calibrated Fanuc-controlled turning/milling centers with inspection per drawing. Final product dispatch is preceded by visual, dimensional, chemical, and mechanical verification with EN 10204 3.1 MTR preparation.

Quality Standards and Certifications

• ISO 9001:2015 – Quality Management System
• ASTM B584 / ASTM B62 – Standard specifications for copper alloy sand castings
• BS 1400 LG2 – British Standard for leaded gunmetal castings
• EN 1982 CC491K – European Standard for copper casting alloys
• IS 318 – Indian Standard for copper alloy ingots and castings
• EN 10204 Type 3.1 MTRs – Chemical analysis + mechanical test data
• ISO 8062-3 CT8–CT10 dimensional tolerance system
• REACH and RoHS compliance declarations available

Why Choose Electrical Accessories India

Electrical Accessories India operates a dedicated copper-alloy foundry with in-house OES chemical analysis, CMM dimensional inspection, and CNC precision machining — delivering 85-5-5-5 bronze castings that fully conform to ASTM, BS, EN, and IS standards. Our ISO 9001:2015 quality system, 20+ years of export experience, and competitive FOB India pricing make us the preferred casting source for valve manufacturers, pump OEMs, electrical component producers, and EPC project contractors in UK, Europe, Middle East, Southeast Asia, and North America. We offer technical support from alloy selection through DFM review, first-article qualification, and production supply with complete traceability documentation.

Frequently Asked Questions – 85-5-5-5 Bronze Casting

Q1: What alloy standards cover 85-5-5-5 bronze?

85-5-5-5 bronze is covered by ASTM B584/B62 (C83600/CDA 836), BS 1400 LG2, EN 1982 CC491K, DIN 1705 (2.1098/RG5), JIS H5111 (CAC406), IS 318 (Grade 2), GOST 613 (БрО5С5Ц5), and GB/T 1176 (ZCuSn5Pb5Zn5) — the most internationally standardized of all copper casting alloys.

Q2: Is 85-5-5-5 bronze a “silicon bronze”?

No. 85-5-5-5 bronze is a leaded quaternary bronze (Cu-Sn-Pb-Zn system). Silicon bronze refers to copper-silicon alloys such as C87300, C87600, and CC212A, which contain no tin or lead. The two alloy families have entirely different compositions and properties, though both fall under the broad “bronze” classification.

Q3: Why is 85-5-5-5 bronze preferred over brass for valve bodies?

Standard brass (Cu-Zn binary alloys) is susceptible to dezincification corrosion in aggressive water service and stress-corrosion cracking in ammonia environments. 85-5-5-5 bronze’s low zinc content (5%) prevents dezincification, and the tin addition suppresses stress-corrosion cracking, making it the engineering-preferred choice for valve bodies, pump casings, and pipe fittings in water works, marine, and chemical process applications.

Q4: What are the minimum casting section thicknesses achievable?

Sand casting: 3 mm minimum wall thickness. Investment casting: 1.5 mm minimum. Permanent mold: 4 mm minimum. Complex internal coring to 8 mm diameter is achievable in sand casting with ceramic cores.

Q5: Can you cast 85-5-5-5 bronze to the Chinese GB/T 1176 standard?

Yes. Electrical Accessories India can produce ZCuSn5Pb5Zn5 castings per GB/T 1176 specifications with full Chinese mill certificate documentation for projects requiring GB compliance. Please specify at the time of enquiry.

Q6: What is the weight range of castings you can supply?

We supply 85-5-5-5 bronze castings ranging from 50 grams (investment cast precision parts) to over 500 kg (large valve bodies and pump casings) per single piece. For very large pieces over 200 kg, please confirm requirements with our technical team for pattern and furnace capacity planning.

Q7: Do you provide heat treatment for 85-5-5-5 castings?

Standard 85-5-5-5 castings do not require heat treatment to achieve specified mechanical properties. Stress-relief annealing at 260°C/1–2 hours is available for dimensionally critical precision-machined components to minimize post-machining distortion in tight-tolerance assemblies.

Q8: What is the difference between 85-5-5-5 bronze and 88-8-4 tin bronze?

88-8-4 (Ounce Metal, C83800) contains higher tin (8%) and lower lead (4%), producing higher strength (275 MPa vs 241 MPa) but lower machinability and higher cost. 85-5-5-5 is the preferred choice for general engineering applications; 88-8-4 is selected when higher tensile strength or hardness is required.

Multilingual Equivalent Terms – 85-5-5-5 Bronze

Related Products and Linked Terms

• Silicon Bronze C83600 – CDA 836 Casting
• LG2 Gunmetal Casting
• C83600 Casting / CDA 836 Casting
• Silicon Bronze Castings (C87300, C87600)
• Phosphor Bronze Casting
• C95500 Aluminum Bronze Casting
• Related Terms: Cu85Sn5Pb5Zn5 casting, quaternary bronze casting, leaded tin zinc bronze, composition bronze ASTM B62, CC491K bronze casting India, RG5 Rotguss casting exporter, CAC406 equivalent casting, ZCuSn5Pb5Zn5 casting, 85-5-5-5 alloy machined parts, pressure-tight bronze casting

Request a Quote – 85-5-5-5 Bronze Alloy Castings

Electrical Accessories India is a leading manufacturer and exporter of 85-5-5-5 bronze alloy castings conforming to ASTM C83600, BS 1400 LG2, EN 1982 CC491K, and IS 318 specifications. Submit your drawing or BOM for a competitive quotation within 24 business hours.

Indicative Price: US$ 13.90/kilogram (FOB India, subject to alloy verification, quantity, and specification. Contact us for project pricing.)

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