Brass Parts India manufactures and exports precision Copper Shims and Copper Shim Washers from Jamnagar, India — supplying aerospace, automotive, precision engineering, electrical, and industrial maintenance customers in the USA and globally. Our copper shims are stamped or cut from certified C11000 electrolytic copper sheet and strip to tight thickness tolerances (±0.002 mm on precision grades), delivering consistent gap-setting, load distribution, and thermal/electrical conductivity performance in demanding applications.
Copper shims are valued for their unique combination of properties: excellent malleability (conforming to mating surface irregularities), high thermal and electrical conductivity, soft texture that prevents scoring of precision surfaces, and natural corrosion resistance. Typical export pricing: USD 0.03 – USD 2.50 per piece CIF US seaport depending on size and thickness.
What Are Copper Shims and Shim Washers?
A copper shim is a thin piece of copper material used to fill small gaps, align components, adjust tolerances, distribute loads, or provide electrical and thermal conductivity across a joint. A copper shim washer is a disc-shaped shim with a central hole — used under bolts, nuts, and bearings to fine-tune preload, correct axial positioning, or seal threaded ports. Copper shims are standard items in engine rebuilding, gearbox assembly, valve timing adjustment, transformer construction, heat sink mounting, and precision machine tool alignment.
Types of Copper Shims and Shim Washers We Manufacture
Copper Shim Washers (Disc Type)
Flat annular washers stamped from copper strip in standard and custom OD × ID × thickness combinations. Used under bolt heads and nuts for load spreading, height adjustment, and sealing. Available in thicknesses from 0.1 mm to 5 mm; OD from 5 mm to 200 mm. Standard metric and imperial hole sizes; custom dimensions to drawing.
Precision Copper Shim Stock (Sheet and Strip)
Rolled copper shim stock supplied in flat sheets (305 × 305 mm / 12″ × 12″ standard) or coil strip form, in thicknesses from 0.025 mm (1 mil) to 3 mm. Used by machinists and engineers to cut custom shim shapes on-site. Thickness tolerance: ±0.002 mm on precision grade, ±0.005 mm on standard grade. Supplied in soft (O60) temper for maximum conformability.
Engine Cylinder Head Copper Shims
High-performance engine head shims used to alter compression ratio, correct deck height, and re-establish proper head gasket sealing in performance engines and rebuilt diesel engines. Available in thicknesses 0.010″ to 0.060″ (0.25–1.5 mm) in soft-annealed C11000 copper. Increasingly specified by US performance engine builders as solid copper head gaskets for racing and high-boost turbocharged applications.
Copper Crusher Washers / Sealing Washers
Soft annealed copper washers used as sealing elements under hydraulic fitting port plugs, drain plugs, banjo bolts, and brake system fittings. The soft copper deforms under tightening to fill thread and surface irregularities, creating a reliable metal-to-metal seal. Standard sizes for metric and SAE banjo bolts, British Standard port fittings, and JIS hydraulic fittings. Available in sizes M8 to M42 (5/16″ to 1-5/8″).
Thermal Interface Copper Shims (Heat Spreaders)
Pure copper shims used as thermal interface layers between power semiconductors (IGBTs, MOSFETs, diodes), CPU/GPU dies, and heat sinks or cold plates. Copper’s thermal conductivity (~390 W/m·K) far exceeds aluminum (~200 W/m·K) and steel (~50 W/m·K), making copper shims the highest-performance solid thermal interface material. Used in power electronics, EV inverters, laser modules, and high-performance computing.
Copper Electrical Shims and Spacers
Conductive copper shims used to maintain contact pressure in electrical switchgear, bus bar joints, transformer coil spacers, and battery cell compression fixtures. Copper’s ≥100% IACS conductivity ensures negligible added resistance at the shim interface. Supplied in precision thicknesses for exact gap control in HV switchgear stacks.
Custom Cut Copper Shims to Drawing
Any 2D profile copper shim — rectangular, square, horseshoe, kidney-shaped, or complex custom profile — laser-cut, waterjet-cut, or stamped from copper sheet to your exact drawing. Tolerances to ±0.05 mm on cut dimensions; ±0.002 mm on thickness for precision shim stock.
Material Grades and International Equivalents
| Grade | Standard | Country | Cu % | Temper | Thermal Conductivity | Best Use |
|---|---|---|---|---|---|---|
| C11000 (ETP) | ASTM B152 | USA | ≥99.9% | O60 (Soft Anneal) | 388 W/m·K | General shims, crusher washers, head gaskets |
| C10200 (OF) | ASTM B152 | USA | ≥99.95% | O50 (Soft) | 391 W/m·K | Thermal interface shims, EV electronics |
| C10100 (OFE) | ASTM B152 | USA | ≥99.99% | O50 | 393 W/m·K | Ultra-high purity; vacuum/semiconductor use |
| CW004A (Cu-ETP) | EN 13601 | Europe | ≥99.9% | R220 | 388 W/m·K | European standard shim applications |
| CW008A (Cu-OF) | EN 13601 | Europe | ≥99.95% | R200 | 391 W/m·K | Precision thermal shims, EU export |
| C1100 | JIS H3100 | Japan | ≥99.9% | O | 388 W/m·K | JIS standard shim applications |
Key Specifications
- Thickness Range: 0.025 mm (1 mil) to 5 mm
- Thickness Tolerance: ±0.002 mm (precision) / ±0.005 mm (standard)
- OD Range (washers): 5 mm to 200 mm
- Temper: O60 soft anneal (standard); H00–H04 harder tempers on request
- Surface: Clean bright, oxide-free; light oil coating for storage protection
- Thermal Conductivity (C11000): ~388 W/m·K
- Electrical Conductivity: ≥100% IACS
- Flatness: ≤0.05 mm per 100 mm for precision shim stock
Applications of Copper Shims
- Engine rebuilding — cylinder head shims, valve stem shims, bearing shims
- Gearbox and transmission shimming for gear mesh adjustment
- Hydraulic and pneumatic system sealing (crusher/banjo washers)
- Power electronics thermal management (CPU, GPU, IGBT, MOSFET)
- Transformer coil spacers and winding insulation
- Electrical switchgear bus bar joints
- CNC machine tool alignment and levelling
- Aerospace structural and engine shimming
- Battery cell compression fixtures in EV packs
- Precision instrument and optic mounting
Why Choose Brass Parts India for Copper Shims?
- Ultra-Tight Thickness Tolerance: ±0.002 mm on precision shim stock — critical for bearing preload and thermal interface applications.
- Pure Copper Guaranteed: C11000/CW004A with mill test certificates; no substitutions or blended scrap.
- Wide Range of Sizes: Standard and custom OD/ID combinations; any 2D shape by stamping or laser cutting.
- Soft Annealed Temper: O60 standard for maximum malleability — conforming perfectly to mating surfaces.
- Competitive Pricing: USD 0.03–USD 2.50/piece CIF US ports.
- Fast Turnaround: Standard shim washers in stock or 2–3 weeks; custom profiles 3–5 weeks.
- ISO 9001 Quality System with thickness inspection on every production lot.
Frequently Asked Questions – Copper Shims
Q1: What is the difference between C11000 and C10200 for thermal shims?
A: C11000 (ETP) contains a small amount of oxygen (0.02–0.04%) which slightly reduces thermal conductivity to ~388 W/m·K. C10200 (oxygen-free) eliminates this oxygen, raising thermal conductivity to ~391 W/m·K and enabling high-temperature hydrogen brazing without embrittlement. For most thermal interface shim applications C11000 is adequate; for semiconductor packaging and vacuum applications, C10200 or C10100 (OFE) is preferred.
Q2: What thickness tolerances can you achieve?
A: Standard shim washers: ±0.005 mm thickness tolerance. Precision shim stock (sheet/strip): ±0.002 mm. For ultra-precision applications requiring ±0.001 mm, we can supply lapped copper shim stock — please enquire with quantity and thickness requirements.
Q3: Can copper shims be used as head gaskets for performance engines?
A: Yes. Solid copper head gaskets are the preferred choice for extreme racing and high-boost turbocharged engines where multi-layer steel (MLS) gaskets may not provide adequate sealing under repeated thermal cycling. We supply soft-annealed C11000 copper shim stock in thicknesses 0.010″ to 0.060″ used by US performance engine builders for custom copper head gaskets. O-ring fire ring grooves and copper annealing after cutting are standard practices.
Q4: Do you supply copper shims for EV battery cell compression?
A: Yes. We supply C10200 oxygen-free copper shims as inter-cell compression washers and thermal interface pads for EV battery module assemblies. Can be supplied with custom 2D profiles, punched holes, and laser-etched identification. Full traceability documentation for automotive Tier 1 supply chains.
Request a Quote
Contact Brass Parts India for copper shims and copper shim washers. Email sales@brass-parts-india.com or call +91 22 4344 9300. CIF pricing to all US seaports. 24-hour response.
