Transformer Spades, Bronze Transformer Spades, NEMA spaced Transformer Spades and Connectors

Transformer Spades, Bronze Transformer Spades, and Transformer Spade Connectors are essential mechanical-electrical components used for secure, high-conductivity joints in Distribution Transformers, Power Transformers, Pole-mounted Transformers, Compact Substations, and Switchgear Assemblies. We are one of the leading manufacturers and exporters of Transformer Spades and Bronze Transformer Spade Connectors from India. We have been supplying Transformer Terminals, Transformer Spades and High-Conductivity Copper Connectors to the world market for many decades. Our capability spans CNC Machining, Precision Forging, Casting, Stamping, 3-Axis & 4-Axis Milling, Surface Finishing, Quality Testing, Heat Treatment, Tooling Development, and Custom Engineering based on client drawings. Each Spade is machined to tight tolerances, ensuring stable transformer performance, low contact resistance, and long-term durability. With more than 30 years of global export experience, BNL  ensures exceptional technical communication, flexible production schedules, and customized labeling or packaging for OEM transformer manufacturers worldwide.

Transformer Spades

Transformer Spades are flat-profile electrical connectors designed for high-amperage, low-contact-resistance power transmission between Transformer Windings, Bushing Rods, Cable Lugs, and Terminal Plates. Manufactured from Electrolytic Tough Pitch (ETP) Copper, Oxygen-Free Copper (OFC), Tin Bronze, Aluminium Bronze, and High-Grade Brass, our spades deliver excellent conductivity, thermal balance, and vibration resistance. These spades are widely used in oil-filled transformers, dry-type transformers, and switchgear junction points, offering consistent electrical performance under repeated tightening cycles, thermal expansion, and mechanical stress.

Bronze Transformer Spades

Bronze Transformer Spades are engineered from high-strength Tin Bronze (CuSn5 / CuSn7 / CuSn10), Aluminium Bronze (C95400 / C95500), and Gunmetal (RG7 / C93200) for applications requiring enhanced mechanical strength, temperature stability, and corrosion resistance. Bronze spades withstand harsh outdoor weather, high torque loads, and transformer vibration. They are ideal for large distribution transformers, industrial power systems, pole-mounted units, and areas with frequent thermal cycling or exposure to moisture. Bronze also provides strong galling-resistance and dimensional stability for long service life.

Transformer Spade Connectors

Transformer Spade Connectors form the primary electrical interface between transformer windings, cable terminations and transformer bushing terminals. These connectors distribute current evenly across the spade face, minimizing localized heating and micro-arcing. Manufactured using precision CNC milling, broaching, drilling, threading, and flattening processes, they are available in Plain, Silver-plated, Tin-plated, and Nickel-plated finishes. Spade connectors can be produced as single-hole, twin-hole, multi-hole, slotted-hole, or NEMA-pattern connectors depending on your mechanical layout.

NEMA Spaced Spades

NEMA Spaced Spades follow ANSI/NEMA dimensional standards, ensuring compatibility with transformers manufactured in North America, Latin America, Canada, Mexico and several global markets. These spades follow NEMA spacing: 44 mm, 57 mm, 63.5 mm, 76.2 mm, depending on the hole configuration. They provide repeatable, predictable mounting tolerances and are commonly used in OEM transformer assembly lines, retrofit maintenance, and UL-certified transformer applications. NEMA Spades are available in Copper, Brass, Bronze, and Silver-plated variants depending on current ratings.

⭐ What Exactly Is NEMA Spacing?

NEMA spacing is the center-to-center distance between bolt holes on a transformer spade connector or terminal plate.

It is normally expressed in inches (also shown in mm), and is consistent across US/Canada transformer OEMs.

⭐ Typical NEMA Spacing Standards for Transformer Spades

These are the most common NEMA hole spacings:

These values correspond exactly to common North American transformer patterns, matching the reference table from your screenshot.

⭐ Where NEMA Spacing Is Used?

• Transformer spade connectors

• LV/HV bushing terminal pads

• Transformer terminal boards

• Copper/bronze spade plates

• Cable lug-to-transformer interfaces

• OEM transformer connection kits

• Utility transformer replacement parts

Bronze Transformer Spade Connectors

Bronze Transformer Spade Connectors are engineered using Aluminium Bronze C95400/C95500/C95800, Tin Bronze CuSn7ZnPb (RG7), CuSn10, and Phosphor Bronze C51000/C52100. These connectors deliver superior tensile strength, impact resistance, and anti-corrosion performance. Their low-maintenance operation, vibration resistance, and ability to maintain shape under high torque make them an ideal choice for demanding transformer environments. They are widely used in electrical utilities, power distribution companies, renewable power installations, mining substations, and heavy-duty industrial transformers.

Material Grades Used

Copper Grades

Bronze Grades

Brass Grades

Manufacturing Processes

Transformer Spades are produced using:

• CNC Turning & Milling

• Vertical Machining Centres (VMC)

• Forging & Heat Treatment

• Casting (if required)

• Power Press Stamping

• Broaching & Deburring

• Surface Finishing (Vibratory + Buffing)

• Thread Rolling

• Silver, Tin or Nickel Plating

• Laser Marking for OEM branding

Machinery Used

• CNC Turning Centers (Doosan, Mazak, Fanuc)

• 4-Axis VMC Machines

• Precision Surface Grinders

• Pneumatic Presses

• Deburring Tumblers

• Coordinate Measuring Machine (CMM)

• Spectrometer (Bruker)

• Tensile Testing Machine

• Plating Line (Silver, Nickel, Tin)

Typical Parts Produced

• Transformer Spades

• NEMA Copper Spades

• Bronze Transformer Spade Connectors

• Multi-hole Transformer Lugs

• Clamp-type Transformer Terminals

• High-current Transformer Studs

• Busbar Spade Assemblies

 Dimensional Table (NEMA Based )

Plating / Surface Finishes

• Tin Plating – Corrosion protection

• Silver Plating – Best conductivity

• Nickel Plating – Wear resistance

• Natural Finish – As machined

Industries Using These Products

• Transformer OEMs

• Electrical Utilities

• EPC Substation Contractors

• Renewable Energy Plants

• Mining Electrification

• Railway Electrification

• Industrial Power Systems

Tolerances

• Machining tolerance: ±0.10 mm

• Hole tolerance: H11

• Flatness: ≤ 0.05 mm

• Plating thickness: 5–8 microns

Turnaround Time

Typical production time: 4–6 weeks, depending on order size, plating requirements, and custom packaging.

Performance Metrics

• Low Contact Resistance

• High Tensile Strength

• Stable Thermal Expansion

• Vibration Resistance

• Long Life in Outdoor Transformers

Why Choose Us?

With 30+ years of global export experience, BNL provides:

• Faster response, accurate communication

• Customized production flexibility (small + large batches)

• Ability to modify drawings for better manufacturability

• Customer-branded packaging & labels

• Proven track record with USA, Europe & Australia transformer OEMs

• Strict quality control, spectrometer analysis, dimensional reports

• Worldwide shipping support

Customer Testimonials

John S. (USA):
“BNL has been our most reliable supplier for Bronze Transformer Spades. Excellent communication, timely delivery, and exceptional engineering support.”

Mark T. (Australia):
“The machining accuracy and surface finish on Bronze Transformer Spades are better than anything we sourced locally. Their customized packaging saved us a lot of assembly time.”

FAQ 

1. What materials are commonly used for Transformer Spades?
   Copper, Brass, Bronze, Aluminium Bronze, Phosphor Bronze depending on current rating and mechanical load.

2. Are NEMA Spades compatible with North American transformers?
   Yes, they follow ANSI/NEMA spacing such as 44 mm, 57 mm, 63.5 mm and 76.2 mm.

3. Do you support OEM custom drawings?
   Yes, our engineering team adjusts drawings for manufacturability and cost efficiency.

4. Can you supply Silver-plated Transformer Spades?
   Yes, Silver plating is available for high-current, low-resistance applications.

5. Do you offer export-grade packaging?
   Yes, including anti-corrosion bags, foam trays, labels and barcodes.

6. Which plating is most durable?
   Nickel plating offers strong durability; Silver gives best conductivity.

7. Can Bronze Spades handle outdoor conditions?
   Absolutely, Aluminium Bronze and Tin Bronze resist corrosion and vibration.

8. What tolerances do you maintain?
   Common machining tolerance is ±0.10 mm with controlled flatness.

9. Do you accept small batch orders?
   Yes, we support prototyping and small-volume production.

10. What is the typical thickness for NEMA Spades?
    Thickness ranges from 6 mm to 12 mm depending on the current rating.

11. Do you supply matching hardware?
    Yes, nuts, washers, studs and bolts can be included.

12. How do you ensure material quality?
    Spectrometer testing, tensile testing and full dimensional inspection.

13. Do you ship worldwide?
    Yes, via DHL, FedEx, Air Cargo and Sea Freight.

14. What is the lead time?
    Standard turnaround time is 4–6 weeks.

15. Do you offer technical consultation?
    Yes, our team advises material selection, plating, and tolerance optimization.

Glossary of Terms:

Spade Connector: A flat conductive plate used for transformer electrical connections.
NEMA Spacing: Standardized hole spacing used in North American transformers.
Tin Bronze: Copper-tin alloy offering good strength and conductivity.
Silver Plating: High-conductivity surface coating used in electrical components.
Transformer Terminal: Interface between winding and external electrical circuits.
OFC Copper: Oxygen-Free Copper with highest electrical conductivity.

Related Parts

Transformer Spade Connectors, Copper Transformer Spades, NEMA Spades, Bronze Electrical Connectors, Transformer Terminal Plates, Silver-Plated Transformer Spades, High-Conductivity Transformer Parts, Power Transformer Terminals, Aluminium Bronze Transformer Spades.

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