Copper 2 Hole Ground Lugs (Crimp Type) are precision-engineered electrical connectors designed to create a secure, low-resistance ground/earth connection between grounding conductors and equipment chassis, bus bars, ground bars, or structural steel. Used extensively across electrical power distribution, utility, industrial, and commercial applications in the USA, these lugs are a cornerstone of effective grounding and bonding systems compliant with NEC Article 250. Cable Glands India manufactures and exports premium Copper 2 Hole Ground Lugs that combine superior conductivity with reliable crimp performance for demanding applications worldwide.
What Are Copper 2 Hole Ground Lugs?
A Copper 2 Hole Ground Lug is a one-piece or two-piece electrical compression terminal that features:
- A barrel section: A cylindrical tube crimped onto the stripped conductor end using a hydraulic, pneumatic, or manual compression tool.
- A tongue (pad) section: A flat, drilled pad with two bolt holes arranged in NEMA standard spacing for mounting to equipment grounding points, bus bars, switchgear frames, or structural ground points.
The “2 hole” designation refers specifically to the two mounting holes in the tongue — a critical distinction from single-hole (1-hole) lugs, as the two-bolt mounting provides superior resistance to rotation and vibration loosening, ensures full surface contact with the mounting surface, and is required by many utility and industrial specifications for large conductor grounding connections. Two-hole lugs are specified throughout NEC-regulated grounding and bonding systems, utility substations, wind and solar energy installations, data centers, and heavy industrial facilities across the USA.
Key Features of Copper 2 Hole Ground Lugs (Crimp Type)
- Material: Electrolytic Tough Pitch (ETP) Copper — C11000 grade — providing 100% IACS conductivity for maximum grounding performance.
- Finish: Bare copper (standard) or electro-tinned (Sn5–Sn10 µm) for oxidation resistance and bi-metallic compatibility.
- NEMA Bolt Spacing: 2-hole tongues conform to NEMA standard bolt hole spacing for direct compatibility with US switchgear, transformer pads, and bus bar systems.
- Conductor Range: #6 AWG through 1000 kcmil (and equivalents in mm² for international use).
- Barrel Type: Long-barrel (for stranded conductor compaction) and short-barrel available; straight or 90° offset configurations.
- Compression Die System: Compatible with standard compression tooling (Thomas & Betts, Burndy, Panduit, Greenlee die systems).
- Temperature Rating: Rated for 75°C and 90°C conductor temperature per NEC and UL listing.
- Standards: Manufactured to UL 486A, NEMA CC1, and IEC 61238-1 specifications.
Copper 2 Hole Ground Lug Material Grades & International Equivalents
The copper alloy selected for ground lugs has a direct impact on conductivity, solderability, and long-term corrosion performance. Here is a comprehensive cross-reference:
| Property | USA (ASTM/UNS) | India (IS/BIS) | UK/Europe (EN/BS) | Germany (DIN) | ISO |
|---|---|---|---|---|---|
| Standard Grade (ETP Copper) | UNS C11000 / ASTM B187 | IS 191 Grade ETP / IS 613 | EN 13601 CW004A (Cu-ETP) | DIN 1787 E-Cu 57 / CW004A | ISO 197 Cu-ETP |
| Conductivity (%IACS) | 100–101% | 100–101% | 100–101% | 100–101% | 100% |
| Tensile Strength | 220–260 MPa (annealed) | 220–260 MPa | 200–250 MPa | 200–250 MPa | — |
| OF Copper (Oxygen-Free) | UNS C10200 / ASTM B170 | IS 191 Grade OF | CW008A (Cu-OF) | SE-Cu / CW008A | ISO 197 Cu-OF |
| Tin Plating | ASTM B545 (electrodeposited Sn) | IS 1573 | BS EN ISO 2093 | DIN 50961 | ISO 2093 |
| Silver Plating (optional) | ASTM B700 | IS 1074 | BS EN ISO 27831 | DIN 50966 | ISO 4521 |
| RoHS Compliance | Yes | Yes | Yes | Yes | EU 2011/65/EU |
| REACH Compliance | Yes | Yes | Yes | Yes | EC 1907/2006 |
Copper 2 Hole Ground Lug Sizes & NEMA Bolt Hole Spacing
NEMA (National Electrical Manufacturers Association) standard bolt hole spacing ensures interchangeability across different manufacturers’ equipment. The table below lists standard configurations available from Cable Glands India:
| Conductor Size (AWG/kcmil) | Conductor Size (mm²) | Bolt Hole Diameter | NEMA Bolt Spacing (C-C) | Tongue Dimensions (W x L) | Barrel Length |
|---|---|---|---|---|---|
| #6 AWG | 16 mm² | 5/16″ (8mm) | 5/8″ (15.9mm) | 1″ x 1.5″ | 1.0″ |
| #4 AWG | 25 mm² | 5/16″ (8mm) | 5/8″ (15.9mm) | 1″ x 1.5″ | 1.0″ |
| #2 AWG | 35 mm² | 3/8″ (9.5mm) | 3/4″ (19.1mm) | 1.25″ x 1.75″ | 1.25″ |
| 1/0 AWG | 50 mm² | 3/8″ (9.5mm) | 3/4″ (19.1mm) | 1.25″ x 2.0″ | 1.5″ |
| 2/0 AWG | 70 mm² | 1/2″ (12.7mm) | 1″ (25.4mm) | 1.5″ x 2.25″ | 1.75″ |
| 3/0 AWG | 95 mm² | 1/2″ (12.7mm) | 1″ (25.4mm) | 1.5″ x 2.5″ | 2.0″ |
| 4/0 AWG | 120 mm² | 1/2″ (12.7mm) | 1″ (25.4mm) | 1.75″ x 2.5″ | 2.0″ |
| 250 kcmil | 150 mm² | 1/2″ (12.7mm) | 1″ (25.4mm) | 2.0″ x 2.75″ | 2.25″ |
| 350 kcmil | 185 mm² | 5/8″ (15.9mm) | 1.25″ (31.8mm) | 2.25″ x 3.0″ | 2.5″ |
| 500 kcmil | 240 mm² | 5/8″ (15.9mm) | 1.25″ (31.8mm) | 2.5″ x 3.25″ | 2.75″ |
| 750 kcmil | 400 mm² | 3/4″ (19mm) | 1.5″ (38.1mm) | 3.0″ x 3.75″ | 3.25″ |
| 1000 kcmil | 500 mm² | 3/4″ (19mm) | 1.5″ (38.1mm) | 3.25″ x 4.0″ | 3.5″ |
Related Products to Copper 2 Hole Ground Lugs
Copper 1 Hole Ground Lugs (Single Hole Crimp Lugs)
Copper 1 Hole Ground Lugs are the standard single-mounting-hole version of grounding lugs, used where a single bolt point is sufficient — typically in smaller conductor sizes or where panel space is limited. Available in the same conductor range and material grades as 2-hole versions.
Copper Compression Splices (Straight Butt Splices)
Copper Compression Splices join two conductors end-to-end within a copper sleeve, creating a continuous grounding path. Inline and offset configurations are available, suitable for below-grade, direct burial, and overhead applications.
Copper Ground Rods & Ground Rod Clamps
Complete grounding systems include Copper-Bonded Ground Rods (5/8″ diameter, 8′ length for USA residential; longer for commercial/utility) and matching Ground Rod Clamps (acorn clamps, pipe clamps, and direct burial lugs) to connect grounding conductors to earth electrodes.
Tinned Copper Ground Lugs
Tinned Copper Ground Lugs are the preferred specification for utility, coastal, and corrosive environment grounding applications. The tin plating (electrodeposited per ASTM B545) protects the base copper from oxidation and sulfidation, maintains low contact resistance over the service life, and makes them compatible with aluminum bus systems under NEC 250.64(E) and NEMA CC1 bi-metallic guidelines.
Aluminum Compression Lugs
For systems with aluminum grounding electrodes or aluminum conductors, Aluminum Compression Lugs (1-hole and 2-hole) are available in AA1350-H19 or AA6061-T6 alloys, with or without tin plating for AL/CU compatibility.
Ground Bars & Grounding Bus
Copper and Aluminum Ground Bars provide a common grounding point for multiple equipment ground conductors in enclosures, panels, and transfer switch assemblies — designed to work directly with our 2-hole ground lugs.
Applications of Copper 2 Hole Ground Lugs in the USA
Copper 2 Hole Ground Lugs (Crimp Type) find critical application across every segment of the US electrical industry:
- Electric Utilities & Substations: Grounding of transformer neutrals, switchgear frames, transmission tower bases, and substation ground grids.
- Commercial Electrical Construction: Equipment grounding conductor (EGC) terminations in switchboards, panelboards, and motor control centers per NEC Article 250.
- Industrial Facilities: Grounding of motors, drives, enclosures, and structural steel in manufacturing plants, refineries, and chemical facilities.
- Data Centers: Signal reference grounding (SRG) and equipment protection grounding in high-density data center installations.
- Renewable Energy: PV array grounding, inverter frame grounding, and wind turbine tower grounding in solar and wind installations.
- Telecom & Broadcasting: Tower grounding, antenna grounding, and broadcast facility protection grounding.
- Transportation: Rail system grounding, bridge grounding, and traffic control system earthing.
- Oil & Gas: Static bonding and grounding of tanks, vessels, and process equipment to prevent electrostatic discharge and lightning damage.
- Marine: Hull bonding, cathodic protection systems, and lightning protection grounding on vessels and piers.
Standards & Certifications for Copper 2 Hole Ground Lugs
Cable Glands India’s Copper 2 Hole Ground Lugs are manufactured to meet the following key standards, particularly relevant for the US market:
- UL 486A-486B – Wire connectors for use with copper and/or aluminum conductors (USA primary standard)
- CSA C22.2 No. 65 – Wire connectors (Canada)
- NEMA CC1 – Electric power connections at substations and related equipment
- IEEE 837 – Qualifying permanent connections used in substation grounding
- ASTM B187 – Copper bus bar, rod, and shapes (material standard)
- ASTM B545 – Electrodeposited tin coatings
- IEC 61238-1 – Compression and mechanical connectors for power cables (international)
- NEC Article 250 – Grounding and bonding (performance standard for USA installations)
- RoHS Directive 2011/65/EU
- REACH Regulation (EC) 1907/2006
Why Choose Cable Glands India for Copper 2 Hole Ground Lugs?
Cable Glands India is a trusted manufacturing partner for copper grounding connectors, serving utility companies, electrical contractors, OEM manufacturers, and distributors in the USA and globally:
- 100% IACS Conductivity: We use only certified C11000 ETP copper (100% IACS) for all ground lugs — no compromises on conductivity performance.
- NEMA-Standard Dimensions: All 2-hole lugs are manufactured to NEMA standard bolt hole spacing, ensuring full interchangeability with US equipment.
- Precision Stamping & Drawing: Lugs are manufactured using precision cold-forging and drawn-seam or seamless tube processes for consistent barrel wall thickness and crimp performance.
- Comprehensive Size Range: #6 AWG through 1000 kcmil in a single source — simplifying procurement across all project sizes.
- Competitive Export Pricing: Direct manufacturer pricing offers USA buyers significant savings versus domestic US manufacturers — without compromising on quality.
- Third-Party Testing: Products available with SGS, Bureau Veritas, or other accredited laboratory test reports on request.
- Custom Configurations: Offset tongues, special hole patterns, custom plating thicknesses, and non-standard barrel dimensions available for OEM customers.
- Fast Delivery: Stock items dispatched within 2–5 business days; custom items in 3–5 weeks.
- Export Expertise: Full HTS code documentation, commercial invoices, packing lists, and COA provided for smooth US customs clearance.
How to Crimp Copper 2 Hole Ground Lugs – Installation Guide
Proper crimping is essential for a reliable, low-resistance grounding connection. Follow these steps for correct installation:
- Select the correct lug: Match the lug conductor size to the actual conductor size. Never use an oversized lug with a smaller conductor.
- Strip the conductor: Strip the insulation to the full barrel insertion depth (typically marked on the barrel or specified in the product datasheet).
- Inspect the conductor: Ensure strands are clean, unoxidized, and not damaged. For aluminum conductors, apply anti-oxidant compound before insertion.
- Insert the conductor fully: Push the stripped conductor into the barrel until the insulation butts up against the barrel entry.
- Select the correct die: Use the die specified for the lug part number and compression tool system (T&B, Burndy, Panduit, Greenlee, etc.).
- Crimp to full compression: Apply the specified number of compressions per the tool/die manufacturer’s instruction. Ensure each crimp overlaps appropriately.
- Inspect the crimp: Verify correct compression using a go/no-go gauge if available. No conductor strands should be visible between the barrel and insulation.
- Mount the lug: Use the appropriate bolt size for the hole diameter, and torque to the specified value per NEC Table 110.14(D) or the equipment manufacturer’s instructions.
Frequently Asked Questions – Copper 2 Hole Ground Lugs (Crimp Type)
Q1. What is a 2 hole ground lug and why are two holes needed?
A 2 hole ground lug has two bolt holes in the tongue (mounting pad) instead of one. The two-bolt mounting provides: (1) superior resistance to rotation and vibration loosening compared to single-bolt lugs; (2) double the contact area with the mounting surface, reducing contact resistance; (3) compliance with utility and industrial specifications that specifically require 2-hole lugs for large conductors. Two-hole lugs are required by many utility company specifications, IEEE 837, and NEMA CC1 for substation and high-fault-current grounding applications.
Q2. What conductor sizes do Copper 2 Hole Ground Lugs accommodate?
Copper 2 Hole Ground Lugs are available for conductor sizes from #6 AWG (approximately 13 mm²) through 1000 kcmil (approximately 500 mm²). This covers the full range of grounding conductor sizes specified in NEC Article 250 for services, feeders, and equipment grounding conductors. Cable Glands India offers the complete size range in one catalog, making it a single-source supplier for all grounding lug requirements.
Q3. Why is ETP Copper (C11000) used for ground lugs?
ETP Copper (UNS C11000) is the standard material for electrical grounding lugs because it provides 100% IACS electrical conductivity — the highest conductivity of any commercially practical copper alloy. C11000 also offers excellent workability for cold-forming manufacturing processes (stamping, drawing, forging), good corrosion resistance, and compatibility with tin plating for enhanced performance. It is the universally accepted material for UL 486A-listed grounding connectors.
Q4. What is the difference between tinned and bare copper ground lugs?
Bare copper ground lugs have no surface coating — they are plain copper. They are suitable for indoor applications where the lug will not be exposed to atmospheric corrosion or moisture, and where the grounding system uses copper conductors throughout. Tinned copper ground lugs have an electrodeposited tin coating (typically 5–10 µm thick). Tin plating provides: oxidation and tarnish resistance (extending service life in outdoor and corrosive environments), compatibility with aluminum conductors and bus bars under bi-metallic guidelines (NEMA CC1), and improved solderability. Tinned lugs are preferred by utilities, marine applications, and coastal/tropical installations.
Q5. What compression tools are compatible with your copper 2 hole ground lugs?
Cable Glands India’s Copper 2 Hole Ground Lugs are designed to be compatible with standard compression tooling systems used in the USA, including Thomas & Betts (T&B), Burndy, Panduit, Greenlee, and Ilsco die systems. The specific die number for each lug size is listed in our product datasheet. Customers should use the die specified for the lug part number to ensure correct crimp geometry and contact resistance. Both manual ratchet crimpers (for smaller sizes) and hydraulic crimp tools (for larger sizes, 1/0 AWG and above) are appropriate.
Q6. Are your copper ground lugs UL 486A listed?
Cable Glands India manufactures copper 2 hole ground lugs to UL 486A-486B dimensional and material specifications. For projects requiring a formal UL listing mark, we can supply products with third-party UL test laboratory certification — please specify at the time of order. For general commercial and industrial applications not subject to AHJ inspection for UL marks, our products are manufactured to equivalent quality and performance standards. Contact our sales team to discuss the specific certification requirements for your project.
Q7. What is the NEMA bolt hole spacing for 2 hole ground lugs?
NEMA standard bolt hole spacing for 2-hole ground lugs varies by conductor size and bolt hole diameter: for 5/16″ holes (smaller conductors), the center-to-center spacing is typically 5/8″; for 3/8″ holes, 3/4″; for 1/2″ holes, 1″; for 5/8″ holes, 1-1/4″; and for 3/4″ holes, 1-1/2″. These spacings correspond to NEMA standard equipment mounting pad dimensions, ensuring that lugs from different manufacturers fit the same equipment mounting points without modification.
Q8. Can copper ground lugs be used with aluminum grounding conductors?
This requires careful consideration. Direct contact between bare copper and aluminum in the presence of moisture creates a galvanic cell that can cause accelerated corrosion of the aluminum conductor (galvanic corrosion). For aluminum-to-copper connections, use: (1) tinned copper lugs (the tin coating acts as a barrier layer), (2) bi-metallic (AL/CU rated) lugs specifically designed and listed for this purpose, and (3) anti-oxidant joint compound. Always verify the lug listing for AL/CU rating per NEMA CC1 and UL 486A before connecting aluminum conductors to copper lugs. NEC 250.64(E) addresses aluminum grounding electrode conductors specifically.
Q9. What bolt torque should be used when mounting copper 2 hole ground lugs?
Bolt torque for mounting copper 2 hole ground lugs should comply with NEC Table 110.14(D) (for unlisted connectors) or the equipment manufacturer’s specifications. Typical torque values range from 20 in-lbs for #10 bolts to 250 in-lbs for 1/2″ bolts. Under-torquing results in high contact resistance and potential overheating; over-torquing can damage the lug tongue or equipment bus. Always use a calibrated torque wrench and apply anti-corrosion compound (Noalox, etc.) between the lug tongue and mounting surface for outdoor and utility applications.
Q10. Are offset (angled) Copper 2 Hole Ground Lugs available?
Yes. In addition to standard straight-tongue configurations, Cable Glands India offers offset copper 2 hole ground lugs in which the tongue is angled (typically 45° or 90°) relative to the barrel axis. Offset lugs are useful in applications where straight access to the conductor is not possible due to space constraints in equipment enclosures, transformer compartments, or switchgear lineups. Custom offset angles are available for OEM applications.
Q11. What is the minimum order quantity for Copper 2 Hole Ground Lugs?
The minimum order quantity for standard Copper 2 Hole Ground Lugs is typically 100 pieces per size for stock items, and 500 pieces for non-stock or custom sizes. Sample orders of 25–50 pieces per size can be arranged for product evaluation — please contact our sales team. For volume orders (10,000+ pieces), we offer priority production, competitive pricing, and dedicated account management. Mixed-size orders are welcome with a minimum total order value.
Q12. How are Copper 2 Hole Ground Lugs packaged for export to the USA?
Copper 2 Hole Ground Lugs are individually sleeved in protective poly bags to prevent scratching and oxidation during transit. Bags are packed in inner boxes (typically 25, 50, or 100 pieces per box) with clear size and specification labeling. Inner boxes are packed in outer export master cartons with full marking per US import requirements. Each shipment includes a Certificate of Conformance (CoC), Material Test Certificate (MTC) for the copper alloy, RoHS Declaration, packing list, and commercial invoice. Country of Origin certificates (Form A / GSP) are available on request for preferential tariff applications.
Q13. What sizes of copper 2 hole ground lugs are most commonly used in USA utility substation grounding?
In USA utility substation grounding applications (per IEEE 837 and utility company specifications), the most commonly used sizes are 4/0 AWG through 500 kcmil for ground grid conductors, and 500 kcmil through 1000 kcmil for main grounding electrode connections. Tinned copper, 2-hole configuration with 1/2″ or 5/8″ bolt holes and NEMA standard spacing is the most frequently specified configuration in utility RFQs and material standards. Cable Glands India maintains stock of these high-demand utility sizes for quick shipment.
Q14. Do you supply documentation for US customs and electrical code compliance?
Yes. Cable Glands India provides comprehensive documentation with all export shipments: Certificate of Conformance stating compliance with UL 486A specifications; Material Test Certificates (MTC) for C11000 copper with chemical composition and mechanical property data; RoHS and REACH Declaration of Compliance; MSDS / SDS for the materials; Commercial Invoice with correct HTS code (typically 8544.42 or 8536.90 depending on product); Packing List; and Certificate of Origin. Additional documents including pre-shipment inspection reports from SGS or Bureau Veritas can be arranged for customers requiring third-party verification.
Get Your Copper 2 Hole Ground Lug Quote Today
Cable Glands India is your one-stop source for premium Copper 2 Hole Ground Lugs (Crimp Type) manufactured to UL 486A specifications and NEMA standard dimensions. Whether you’re a utility contractor, electrical distributor, OEM equipment manufacturer, or project manager, we have the product, quality, and logistics capability to serve your needs competitively.
📧 Email: sales@cableglandsindia.com
📞 Phone: +91 22 4344 9300
🌐 Website: www.cableglandsindia.com