Split Bolt vs. Mechanical Lug | Choosing the Right Electrical Connector

Split Bolt vs. Mechanical Lug: Choosing the Right Electrical Connector

In the electrical distribution world, few decisions are as common — and as important — as choosing the right connector for splicing and terminating conductors. Two of the most widely used mechanical connectors are the split bolt connector and the mechanical lug. Both have their place in power distribution, grounding, and splicing, but the right choice depends on conductor size, application, installation environment, and cost considerations.

At Conversions Tech, we supply both styles of connectors, with a complete range of UL-listed split bolt connectors (6 AWG through 600 MCM). In this guide, we’ll compare split bolts and mechanical lugs side-by-side so you can make an informed choice.

What Are Split Bolt Connectors?

A split bolt connector is a heavy-duty, reusable fastener used to join two or more conductors. Shaped like a bolt with a longitudinal split, it allows wires to be wrapped around the body and clamped in place by a tightening nut. The result is a mechanically secure, electrically conductive joint suitable for both splicing and grounding applications.

• Material: High-strength copper alloy, often tin-plated for copper/aluminum compatibility.
• Sizes: 6 AWG through 600 MCM conductor ranges.
• Standards: UL/CSA listed, NEC compliant for grounding and splicing.
• Applications: Panelboard splicing, grounding rods, service entrances, feeders, and industrial wiring.

👉 See our full Split Bolt Connector Catalog for available sizes.

What Are Mechanical Lugs?

Mechanical lugs are compression-style connectors that use one or more set screws to secure conductors in place. Typically made of tin-plated aluminum, they are widely used for terminating cables into panels, breakers, or equipment. Mechanical lugs are fast to install and provide reliable electrical performance when sized and torqued correctly.

• Material: Tin-plated aluminum alloy with stainless steel set screws.
• Sizes: Wide range, typically 14 AWG through 1000 MCM.
• Standards: UL listed, NEC 110.14 compliant.
• Applications: Terminating conductors into equipment, panelboards, breakers, disconnects, and bus bars.

Split Bolt vs. Mechanical Lug — Key Differences

Although both connectors achieve the same goal — electrically joining conductors — the way they do it, and the environments they excel in, are different. Below is a breakdown of the most important differences.

1. Reusability

Split bolts can be loosened and reused in many cases, making them valuable for field adjustments or temporary connections. Mechanical lugs are semi-permanent: repeated tightening of set screws can strip threads or deform the conductor, reducing reusability.

2. Conductor Range

Split bolts excel at joining multiple conductors of varying sizes (within their range). For example, a 4/0 split bolt can accommodate multiple #2 AWG wires or a mix of 2/0 and 1/0. Mechanical lugs, on the other hand, are designed for specific conductor sizes and are less flexible in multi-wire splicing.

3. Installation Tools

Installing a split bolt requires only a wrench, but proper torque is critical. Mechanical lugs require a hex or torque wrench for tightening set screws. Both methods demand following the manufacturer’s torque specs to ensure conductivity and prevent overheating.

4. Cost

Split bolts are generally more cost-effective for splicing conductors, especially in high volumes. Mechanical lugs are more expensive but can save labor time in panel terminations.

5. Code Compliance

Both split bolts and lugs are NEC compliant when used correctly. However, split bolts must be insulated when used in energized enclosures, while mechanical lugs are often supplied pre-insulated or with insulating covers.

6. Space Considerations

Split bolts are compact and can fit into tight spaces, making them ideal for crowded junction boxes. Mechanical lugs are bulkier and require more mounting space.

When to Use Split Bolts

• Grounding Applications: Bonding conductors to rods or building steel.
• Splicing Large Conductors: Where a compact, reliable connection is needed.
• Underground Splicing: With insulating tape wrap for NEC compliance.
• Temporary/Field Connections: Where conductors may need to be adjusted or repositioned.

When to Use Mechanical Lugs

• Terminating into Equipment: Panelboards, breakers, disconnect switches, transformers.
• Multi-tap Connections: Large lugs with multiple ports for multiple conductors.
• Permanent Terminations: Where the conductor will remain fixed long-term.
• Where Insulated Options Are Preferred: Factory-insulated lugs simplify code compliance.

Split Bolt vs. Lug — Comparison Table

Feature	Split Bolt	Mechanical Lug
Best For	Splicing, grounding	Terminating into equipment
Conductor Sizes	6 AWG – 600 MCM	14 AWG – 1000 MCM
Multi-Conductor?	Yes, flexible	Limited
Reusability	Yes (field adjustable)	Limited
Insulation Needed	Yes (tape wrap)	Usually provided
Cost	Lower	Higher

Industry Standards and Competitors

Both connector types are manufactured by major electrical brands such as Burndy, Blackburn (ABB), Ilsco, and NSi. At Conversions Tech, our split bolt connectors are engineered to match or exceed these industry standards while offering superior lead times, logistics, and pricing.

Conclusion: Which Connector Should You Choose?

The choice between a split bolt and a mechanical lug depends on your application:

• If you are splicing conductors, joining copper to aluminum, or bonding to ground rods → choose a split bolt connector.
• If you are terminating into equipment like a breaker, disconnect, or panelboard → use a mechanical lug.

Both are code-compliant and safe when installed correctly, but split bolts remain the go-to for splicing flexibility, cost savings, and compact installations.

Ready to order?
Explore the full Conversions Tech Split Bolt Connector Catalog — available in copper and tin-plated bronze, from 6 AWG to 600 MCM.