Bronze Transformer Spades, Transformer Spade Connectors, Transformer Spade Terminals

Price: US$ 14.10/Kilogram
High-Conductivity • NEMA-Spaced • Precision-Machined Copper-Alloy Transformer Connectors
1. PRODUCT OVERVIEW
Bronze Transformer Spade Terminals (also called Transformer Spade Connectors or Transformer Spades) are high-current, bolted electrical connectors used to interface transformer bushings, busbars, and cable lugs. Manufactured from high-strength copper-based alloys such as Tin-Bronze (C83600), Leaded Bronze (C92200), Silicon Bronze, or Aluminum-Bronze (C95400/C95500), these spades deliver excellent mechanical strength, corrosion resistance, and stable electrical performance in demanding transformer environments.
Typical uses include distribution transformers, power transformers, switchgear, grounding networks, solar/wind power transformers, and industrial electrical distribution systems.
2. KEY FEATURES
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✔ High Conductivity Copper-Alloy Construction
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✔ NEMA-Standard Hole Spacing for interchangeability
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✔ 2, 4, 6 or 8-Hole Configurations
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✔ 5/8″-11 and 1″-14 Stud Compatibility
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✔ Tin-Plating or Bare Bronze Options
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✔ CNC-Machined / Precision Cast for dimensional accuracy
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✔ Custom Sizes, Thicknesses & Hole Patterns Available
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✔ Supports High Mechanical Torque & Thermal Cycling
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✔ Suitable for LV & HV Transformer Bushings
3. MATERIAL GRADES (INTERNATIONAL EQUIVALENTS)
| Alloy Group | USA ASTM | Europe EN | JIS | China GB | Notes |
|---|---|---|---|---|---|
| Tin Bronze | C83600 / SAE 40 | CuSn7ZnPb | BC6 | ZCuSn7Zn4Pb7 | Good strength, corrosion resistance |
| Leaded Bronze | C92200 | CuSn8Pb | BC7 | ZCuSn10Pb1 | Excellent machinability |
| Silicon Bronze | C65500 | CuSi3Mn1 | C6511 | QSi3-1 | Superior corrosion resistance |
| Aluminum Bronze | C95400 / C95500 | CuAl10Fe5Ni5 | CAC703 | QAl10-4-4 | High mechanical strength |
| High Conductivity Copper | C11000 | Cu-ETP | C1100 | T2 | Maximum electrical conductivity |
4. MANUFACTURING PROCESSES
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Green Sand Casting / Shell Mould Casting
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Gravity Die Casting
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CNC Milling & Drilling (±0.05 mm tolerance achievable)
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Threading (UNC / UNF)
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Surface Treatment: Tin-Plating, Nickel-Plating, Anti-Oxidation Coating
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100% Visual + Dimensional Inspection
5. STANDARD PRODUCT RANGE
Transformer Spade Terminals – NEMA Spacing – Bronze / Copper-Alloy

A) 2-HOLE BRONZE TRANSFORMER SPADE TERMINALS
| Part No. | Holes | Hole Ø (in) | Spacing (in) | Width W (in) | Length L (in) | Thickness T (in) | Stud Size |
|---|---|---|---|---|---|---|---|
| ST-2H-137 | 2 | 9/16″ | 1.75″ | 1.37″ | 5.06″ | 0.31″ | 5/8″-11 |
| ST-2H-193 | 2 | 9/16″ | 1.75″ | 1.93″ | 5.12″ | 0.34″ | 5/8″-11 |
| ST-2H-250 | 2 | 9/16″ | 1.75″ | 2.50″ | 5.25″ | 0.38″ | 1″-14 |
B) 4-HOLE BRONZE TRANSFORMER SPADE TERMINALS
| Part No. | Holes | Hole Ø | Spacing | Width W | Length L | Thickness T | Stud Size |
|---|---|---|---|---|---|---|---|
| ST-4H-137 | 4 (single row) | 9/16″ | 1.75″ | 1.37″ | 7.50″ | 0.31″ | 5/8″-11 |
| ST-4H-193 | 4 | 9/16″ | 1.75″ | 1.93″ | 7.62″ | 0.34″ | 5/8″-11 |
| ST-4H-250 | 4 (wide) | 9/16″ | 1.75″ | 2.50″ | 7.75″ | 0.38″ | 1″-14 |
C) 6-HOLE BRONZE TRANSFORMER SPADE TERMINALS
| Part No. | Holes | Hole Ø | Spacing | Width W | Length L | Thickness T | Stud Size |
|---|---|---|---|---|---|---|---|
| ST-6H-137 | 6 | 9/16″ | 1.75″ | 1.37″ | 10.0″ | 0.31″ | 5/8″-11 |
| ST-6H-193 | 6 | 9/56″ | 1.75″ | 1.93″ | 10.2″ | 0.34″ | 5/8″-11 |
| ST-6H-250 | 6 | 9/56″ | 1.75″ | 2.50″ | 10.4″ | 0.38″ | 1″-14 |
D) 8-HOLE BRONZE TRANSFORMER SPADE TERMINALS
| Part No. | Holes | Hole Ø | Spacing | Width W | Length L | Thickness T | Stud Size |
|---|---|---|---|---|---|---|---|
| ST-8H-137 | 8 | 9/16″ | 1.75″ | 1.37″ | 12.5″ | 0.31″ | 5/8″-11 |
| ST-8H-193 | 8 | 9/16″ | 1.75″ | 1.93″ | 12.7″ | 0.34″ | 5/8″-11 |
| ST-8H-250 | 8 | 9/56″ | 1.75″ | 2.50″ | 12.9″ | 0.38″ | 1″-14 |
6. OPTIONAL CUSTOMIZATIONS
| Custom Option | Availability |
|---|---|
| Alloy: C83600 / C92200 / C95400 / C95500 / C11000 | ✔ |
| Tin / Nickel / Silver Anti-Oxidation Coatings | ✔ |
| Custom Hole Patterns (Metric & Imperial) | ✔ |
| Double-Row Spade Terminals | ✔ |
| Spades with TIG/Welded Studs | ✔ |
| Thickness from 6 mm to 20 mm | ✔ |
| CNC-Machined Edges & Radii | ✔ |
| High-Current Wide Spade Designs | ✔ |
7. TYPICAL APPLICATIONS
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Power Transformers (HV/LV Bushings)
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Distribution Transformers
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Switchgear Busbar Connections
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Substation Hardware
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Solar/Wind Power Transformers
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Railways & Industrial Electrical Systems
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Grounding Networks
8. PERFORMANCE METRICS
| Parameter | Typical Value |
|---|---|
| Electrical Conductivity | 12–28% IACS (depending on bronze grade) |
| Operating Temperature | −20°C to +180°C |
| Mechanical Tensile Strength | 250–650 MPa |
| Contact Resistance | < 80 µΩ (tin-plated) |
| Maximum Torque | 45–90 Nm (stud size dependent) |
9. WHY CHOOSE OUR BRONZE TRANSFORMER SPADE TERMINALS?
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Precision CNC machined for perfect NEMA spacing
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High-strength alloys suited for repetitive thermal stress
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Low-contact resistance with smooth, burr-free surfaces
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Designed for long service life in outdoor environments
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Short lead times – 4–6 weeks
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Worldwide export-ready packaging
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Custom designs available within 48 hours
USA Sales: We are a trusted global supplier of precision metal parts for the electrical industry, proudly partnering with leading USA companies to power innovation and infrastructure. From Fortune 500 manufacturers to innovative tech giants, our high-quality components meet rigorous U.S. standards for performance, durability, and safety. By combining advanced manufacturing with reliable delivery and dedicated stateside support, we help American businesses streamline supply chains, reduce costs, and drive the future of electrical systems, renewable energy, and smart grid technology. Choose a supplier engineered for the demands of the U.S. market. We can also offer DDP pricing within USA to every possible state.