Name: China Spring-Grade RA Bronze Foil Manufacturers Suppliers Factory - Civen Metal
Brand: Civen
SKU: 315664688

Civen Metal Material (Shanghai) Co., Ltd. is one of the leading manufacturers and suppliers of spring-grade ra bronze foil in China. Welcome to buy bulk durable spring-grade ra bronze foil made in China here from our factory. If you have any enquiry about cooperation, please feel free to email us.

CIVEN Metal Spring-Grade Rolled-Annealed (RA) Bronze Foil is a cold-rolled copper-tin alloy engineered for high-cycle spring performance and precise electrical conductivity. Processed through multi-stage cold rolling and controlled annealing, it provides targeted tensile strength and fatigue resistance for micro-electronic and electromechanical components.

Key Material

Alloy Design: Copper-tin binary and phosphor-bronze variants (UNS C51900 / CuSn6 or UNS C52100 / CuSn8), alloyed with 0.03% to 0.35% phosphorus.

Metallurgical Structure: Homogeneous alpha-phase crystal structure, eliminating segregation and inclusions that cause stress concentration.

Compliance Standards: ASTM B103/B103M, EN 1654, JIS H3110.

Performance Features

Elastic Limit: Withstands high bending stresses without permanent plastic deformation.

Fatigue Resistance: Resists micro-cracking under repeated reverse bending cycles.

Electrical Conductivity: Maintains 13% to 20% IACS depending on alloy grade.

Formability: Balances high spring temper with sufficient ductility for moderate radius bending.

Corrosion Resistance: Forms a dense copper-oxide and tin-oxide passivation layer.

Technical Specifications

Parameter	Specification Range	Test Standard
Thickness (t)	0.02 mm to 0.80 mm	ISO 506 / ASTM E252
Thickness Tolerance	+/- 0.001 mm to +/- 0.005 mm	ISO 506
Width (w)	5 mm to 600 mm	Direct measurement
Width Tolerance	+/- 0.05 mm (Slitted edge)	DIN 17745
Tensile Strength (Rm)	550 MPa to 950 MPa	ASTM E8 / EN ISO 6892-1
Elongation (A50)	2% to 12%	ASTM E8
Hardness	160 HV to 320 HV	ASTM E384 (Vickers)
Electrical Conductivity	13% to 20% IACS at 20 deg C	ASTM E1004
Surface Finish	Bright, smooth mill finish (Ra <= 0.4 um)	ISO 4287

Manufacturing & Quality Control

Melting & Casting: Vacuum induction melting followed by continuous casting.

Precision Cold Rolling: Processed on 20-high Sendzimir (Z-mill) reversible stands with real-time AGC systems and inline laser thickness sensors, controlling thickness variations within +/- 1 um.

Annealing: Bell-type furnaces operating under protective nitrogen-hydrogen atmospheres.

Edge Conditioning: Rotary slitting lines with tungsten carbide tooling for burr-less edges.

Quality Systems & Inspection: Certified under ISO 9001:2015 and IATF 16949. Compliant with RoHS and REACH. 100% online eddy current testing, ASTM E8 destructive tensile testing, ASTM E384 microhardness testing, and optical microscopic grain size analysis.

Applications

Precision Switches

Snap-action switch blades and movable contact arms.

Battery Springs

Terminal plates in cylindrical and prismatic battery holders.

Automotive Connectors

Interconnect terminals and sensor spring clips rated up to 125 deg C.

Telecommunications

Shielding fingers, grounding clips, and coaxial connector springs.

Instruments

Diaphragms, bourdon tubes, and mechanical clockwork springs.

Customization & OEM Supply

Alloy Tuning: Tin and phosphorus ratios adjusted for specific electrical resistance or stamping ductility.
Dimensions: Non-standard thicknesses and slit widths produced to customer blueprints.
Surface Treatments: Pre-cleaning, passivation, or selective electroplating (tin, silver, or nickel flash).
Coil Configuration: Inner diameters (75 mm, 150 mm, 300 mm), outer coil weights up to 500 kg, and level-wound spooling.

Packaging & Delivery

Corrosion Protection

Interleaved with VCI paper and vacuum-sealed in moisture-barrier polyethylene bags with desiccant gel.

Mechanical Protection

Suspended inside fumigated wooden crates or steel-strapped pallets with edge protectors.

Documentation

Mill Test Certificates (MTC) per EN 10204 3.1 included with every shipment.

Why CIVEN Metal

Mill-Direct Control: Vertical integration from raw ingot casting to precision slitting.
Tolerance Management: Sendzimir rolling mills restrict thickness deviations to microns.
Traceability: Lot traceability linking chemical composition reports to master coils under IATF 16949 controls.
Engineering Support: Metallurgical assistance for alloy selection, temper optimization, and stamping behavior analysis.

FAQ

Q: What is the difference between RA bronze foil and hard-rolled electrolytic copper foil?

A: RA bronze foil is an alloy of copper, tin, and phosphorus processed via controlled cold rolling and annealing for high spring elasticity and fatigue resistance. Electrolytic copper foil is electro-deposited with lower tensile strength, suited for PCB traces rather than mechanical springs.

Q: How do you prevent edge burrs during slitting?

A: Tungsten carbide slitting blades with laser optical gap monitoring maintain shear clearance at 10% of foil thickness.

Q: Can you supply material with specific grain size requirements for chemical etching?

A: Yes. Annealing cycles are controlled to achieve an ultrafine grain size (< 0.015 mm) to prevent uneven undercut during acid etching.

Q: What is the standard Minimum Order Quantity (MOQ)?

A: Standard MOQ is 300 kg per item configuration. Trial orders for prototyping are available upon technical review.

Q: What compliance documentation is provided?

A: MTC per EN 10204 3.1 detailing chemistry, mechanical properties, actual dimensions, and ISO 9001, IATF 16949, RoHS, and REACH declarations.

Hot Tags: spring-grade ra bronze foil, China spring-grade ra bronze foil manufacturers, suppliers, factory, Beryllium Copper Foil, Copper Nickel Foil, High precision RA Brass Foil, RA Bronze Foil, RA Copper Foil, Rolled Brass Foil

Spring-Grade RA Bronze Foil