Copper Studs, Copper Studs for Transformers (Half-Threaded UNC Studs for Bronze Spade Connectors)

 Precision Copper & Bronze Transformer Hardware

Overview

Copper Studs for Transformers are precision-machined, high-conductivity fasteners used to create a secure mechanical and electrical interface between transformer bushings and bronze/copper spade connectors.
These half-threaded studs are designed in UNC thread series (1/2″ & 5/8″), ensuring strong load-bearing capability, vibration resistance, and compatibility with standard bronze straight-bolt terminals, bronze spades, palm connectors, and transformer terminal hardware.

Manufactured from oxygen-free high-conductivity (OFHC) or electrolytic-tough-pitch (ETP) copper, these studs provide excellent thermal and electrical conductivity, stability under overload, and corrosion resistance essential for distribution transformers, power transformers, and substation switchgear.

Price: US$ 13.50/Kilogram 

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Key Features

• UNC Thread Sizes: 1/2″-13 UNC & 5/8″-11 UNC (custom threads available on request)

• Half-threaded design for optimal clamping strength

• High conductivity copper grades for minimal electrical loss

• Compatible with Bronze Spade Connectors & NEMA-spaced terminals

• Machined on CNC/VMC for dimensional precision

• Smooth radius transitions to avoid stress points

• Silver, Tin, or Nickel plated (optional) for enhanced corrosion protection

• Meets ASTM, IS, and IEC transformer hardware standards

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Material Grades (Global Equivalents)

Copper Grades Used

Custom forging-grade copper available upon request.

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Manufacturing Processes

• CNC & VMC machining for tight tolerances

• Centerless turning / precision threading

• Rolling or cutting of UNC threads depending on application

• Heat treatment & stress relief (optional)

• Surface finishing including polishing, plating & passivation

• QC inspection on CMM, thread gauges, hardness & conductivity tests

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Typical Applications

Copper Studs are widely used in:

• Distribution Transformers (11kV / 33kV)

• Power Transformers (66kV / 132kV / 220kV)

• Substation Bronze Connector Assemblies

• Transformer Bushings

• Bronze Straight Bolt Terminals

• Transformer Spade/Palm Connectors

• Heavy-duty electrical mechanical joints

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Design & Dimensional Options

Standard UNC Sizes

• 1/2″-13 UNC Half Thread

• 5/8″-11 UNC Half Thread

Length Options

• 2″

• 2.5″

• 3″

• 4″

• 6″

• 8″
  (or as per customer drawing)

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Surface Finish Options

• Natural Copper (polished)

• Tin Plating – 3 to 10 microns

• Silver Plating – 5 to 15 microns (low resistance, high conductivity)

• Nickel Plating – 5 to 10 microns (corrosion & heat protection)

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Industries Served

• Power & Distribution Transformer Manufacturers

• Substation Hardware & Electrical Utilities

• Energy, Mining & Oil-Gas Equipment

• Renewable Power Infrastructure

• Railways & Heavy Electrical OEMs

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Why Choose Conex Metals Copper Studs?

• Guaranteed 99.9% purity copper

• High torque resistance for reliable bolted joints

• Perfect alignment with Bronze Spade Connectors

• Fast lead time: 4–6 weeks worldwide shipping

• Custom threading, lengths & plating available

• Tight tolerance control on major/minor diameter, pitch & straightness

• Decades of experience supplying global transformer OEMs

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Technical Data (Typical)

(Exact values depend on material grade)

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Frequently Asked Questions (Transformer Hardware SEO)

1. What grade of copper is best for transformer studs?

ETP Copper (C11000) is preferred for cost & conductivity, while OFHC Copper (C10100) is chosen for high-end transformers.

2. Are these studs compatible with Bronze Spade Connectors?

Yes, they are specifically designed for bronze spade/palm terminals and bushing clamps.

3. Why use UNC instead of metric threads?

UNC threads have a deeper profile, offering better load distribution and higher pull-out strength—ideal for transformers.

4. Can you supply custom lengths?

Yes. Anything from 1 inch to 8 inches or per drawing.

5. Do copper studs require plating?

Not mandatory, but tin or silver plating improves corrosion resistance and electrical reliability.

6. Are these studs used in both HV and LV transformers?

Commonly in LV terminals, but certain HV applications also use plated copper studs.

7. Can I use these studs with aluminum connectors?

Not recommended without bimetal washers to prevent galvanic corrosion.

8. What torque should be applied?

Depends on stud size & connector type; typical 22–45 Nm.

9. Do you provide testing certifications?

Yes – chemical composition, mechanical tests, plating thickness, dimensional reports.

10. Are CMM inspection reports available?

Yes, on request for PPAP/APQP requirements.

11. Can these studs withstand high temperatures?

Copper maintains structural integrity up to 200–250°C.

12. Is silver plating better than tin?

For high-load and low-resistance joints, yes. Silver reduces contact resistance.

13. Are double-ended or fully threaded studs available?

Yes, as custom variants.

14. Do you deliver globally?

Yes—USA, Mexico, Europe, Middle East, South America, Australia.

15. What is the delivery time?

Standard: 4–6 weeks, faster for repeat orders.

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Request a Quote / Technical Drawing

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.