Cable Glands India manufactures high-conductivity Copper Split Bolts and Copper Line Taps (also called parallel groove clamps or tap connectors) for electrical power distribution, utility grids, and industrial wiring systems. Produced from electrolytic tough pitch (ETP) copper at our Jamnagar, India facility, our split bolts and line taps are exported to the USA, UK, Canada, Australia, South Africa, and the Middle East, serving electrical utilities, electrical contractors, and industrial OEMs.

What Are Copper Split Bolts and Line Taps?

A copper split bolt connector (also called a split bolt tap, parallel bolt connector, or cable tap connector) consists of a U-shaped copper body with a threaded bolt and nut that clamps two conductors together — a main conductor passing through the slot and a tap conductor clamped by the bolt. Used extensively for splicing, tapping, and joining copper or aluminium conductors without soldering. A copper line tap (parallel groove clamp or H-tap) achieves the same purpose using parallel grooves machined in the connector body to hold the main and tap conductors, with bolts clamping through both grooves simultaneously. Both types are available with or without insulating covers.

Types of Copper Split Bolts and Line Taps We Manufacture

1. Standard Copper Split Bolt Connectors (Single Bolt, UL Listed Range)

Single-bolt split bolt connectors for #14 AWG to 1000 kcmil conductor range. Body machined from high-conductivity ETP copper (ASTM B187, minimum 99.9% Cu, 100% IACS conductivity). Bolt in silicon bronze or stainless steel for corrosion resistance. Compliant with UL 486A-486B and CSA C22.2 No.65. Suitable for copper-to-copper connections.

2. Copper Split Bolt Connectors for Aluminium Conductors (Cu-Al Rated)

Rated for aluminium-to-aluminium and copper-to-aluminium conductor combinations. Body machined from 99.9% ETP copper with tin-plated contact surfaces to prevent galvanic corrosion at the aluminium interface. Marked AL/CU for field identification. Meets UL 486A-486B Al/Cu rating. Conductor range: #6 AWG to 750 kcmil for aluminium conductors.

3. Parallel Groove (H-Tap) Copper Line Taps

Two-bolt or three-bolt H-tap connectors with parallel grooves machined to accept main and branch conductors simultaneously. The parallel groove design provides superior contact area versus split bolt designs for the same conductor sizes, reducing joint resistance. Available in H1, H2, and H3 bolt configurations for different main-to-tap conductor combinations per NEMA CC1.

4. Insulated Split Bolt Connectors (With Polymer Cover)

Copper split bolt body pre-assembled with a two-part self-closing insulating cover in UV-stabilised polyethylene or thermoplastic rubber (TPR). The cover snaps over the connector body after conductor installation, providing 600V insulation equivalent to taped connections. Colour-coded covers available for phase identification (black, red, blue, white/grey, green). Eliminates need for electrical tape or heat-shrink tubing.

5. Hot-Line Tap Connectors (Live-Line Working Type)

Specially designed for live-line (hot-stick) installation on energised overhead distribution conductors. Features a captive bolt and nut that cannot be dropped, and a groove geometry that accepts the conductor without sliding along the main line. Manufactured in electrolytic copper with silicon bronze hardware for corrosion resistance in outdoor environments. Used by utility line workers for service drop taps.

6. Copper C-Tap (Compression-Type Line Tap)

C-shaped compression connectors installed with a hydraulic or ratchet crimping tool. Provide a cold-welded, gas-tight connection with zero maintenance. Available for copper-to-copper and aluminium-to-copper combinations. Connector body in ETP copper with tin or tin-silver plating. Widely used in utility underground distribution (UD) systems, transformer secondary connections, and service entrances.

7. Aerial Bundle Cable (ABC) Line Taps

Designed for tapping into aerial bundled cable systems — the piercing tap design penetrates the insulation of the main ABC conductor to make electrical contact without stripping insulation. Used extensively in European and developing-country distribution networks for street lighting taps and service connections.

8. High-Voltage Line Taps (15 kV and 35 kV Class)

Heavy-duty parallel groove clamps for primary distribution voltage levels (15 kV to 35 kV). Designed to ANSI C119.4 standard for overhead line connectors. Connector body in ETP copper or silicon bronze, bolts in stainless steel. Contact surfaces machined flat and tin-plated for reliable, low-resistance connection on stranded ACSR or AAC conductors.

Related Products and Accessories

• Copper battery terminal connectors and lugs
• Copper compression cable lugs (DIN, BS, ASTM)
• Copper earth clamps and ground clamps
• Bronze rebar grounding clamps
• Copper busbar connectors
• Silicon bronze bolts and nuts (for marine applications)
• Insulating covers and boots for connectors
• Copper bonding jumpers and grounding straps

Material Grades & International Equivalents

Standard	Grade	Country/Region	Conductivity
ASTM	B187 (ETP Copper)	USA	Min 100% IACS
EN	CW004A (Cu-ETP)	Europe	Min 100% IACS
BS	C101 (ETP)	UK	Min 100% IACS
DIN	E-Cu57 (2.0060)	Germany	57 MS/m min
JIS	C1100	Japan	Min 99% IACS
IS	191 Grade 1	India	Min 100% IACS

Technical Specifications

Parameter	Specification
Body Material	Electrolytic Tough Pitch Copper (ETP, 99.9% min Cu)
Hardware	Silicon Bronze (C65100) or Stainless Steel 316 bolts & nuts
Plating	Natural, Tin-plated (for Al/Cu use), or Tin-silver plated
Conductor Range	#14 AWG to 1000 kcmil (copper); #6 AWG to 750 kcmil (aluminium)
Voltage Rating	600V (standard); up to 35 kV (high-voltage class)
Standards	UL 486A-486B, CSA C22.2 No.65, NEMA CC1, ANSI C119.4
Temperature Rating	75°C or 90°C conductor temperature rating

Applications

• Electrical service entrance conductor splices and taps
• Overhead utility distribution line taps (hot-line clamps)
• Underground distribution transformer secondary connections
• Industrial switchgear and MCC busbar tapping
• Grounding and bonding of structural steel and rebar
• Telecommunications cable bonding
• Solar PV string combiner box wiring
• Data centre power distribution bus taps

Why Choose Cable Glands India for Copper Split Bolts and Line Taps?

• High-Conductivity ETP Copper: All connectors machined from ASTM B187 or EN CW004A electrolytic copper — verified by spectrometer analysis at incoming material inspection.
• ISO 9001:2015 Certified: Full material traceability, dimensional inspection, and contact resistance testing included with each production batch.
• UL Compliance Capability: Products manufactured to UL 486A-486B dimensional and performance criteria; third-party UL listing available on request for specific SKUs.
• Complete Conductor Range: Split bolts and line taps available from #14 AWG through 1000 kcmil in a single supply source.
• Cu/Al Dual Rated: Tin-plated variants for aluminium conductor connections prevent galvanic corrosion at the contact interface.
• 30–60% Cost Advantage: Competitive landed costs for US, UK, and European buyers versus domestic manufacturers.
• Custom Sizes: Non-standard main conductor slot widths, bespoke bolt torque specifications, and custom conductor combinations available with engineering drawing approval.

Frequently Asked Questions (FAQ)

Q1. What is a copper split bolt connector used for?

A copper split bolt connector is used to mechanically and electrically join or tap two electrical conductors — a main conductor (passing through the slot) and a branch or tap conductor (clamped alongside the main by the bolt). Common applications include service entrance taps, outdoor overhead line taps, grounding connections, and junction box splices where soldering is not practical. The bolt is tightened to the manufacturer’s specified torque to ensure adequate contact pressure for low joint resistance.

Q2. What is the difference between a split bolt and a parallel groove (H-tap) connector?

A split bolt has a U-shaped slot through which the main conductor passes; the tap conductor is placed alongside, and a single bolt clamps both. A parallel groove (H-tap) connector has two separate grooves — one for the main conductor and one for the tap — clamped by two or three bolts passing through the connector body between the grooves. H-taps provide greater contact area, lower joint resistance, and superior vibration resistance compared to split bolts for the same conductor sizes.

Q3. Can copper split bolts be used with aluminium conductors?

Yes, but only with specific Al/Cu rated and tin-plated split bolt connectors. Standard copper split bolts in direct contact with aluminium conductors create a galvanic couple (aluminium is anodic to copper) that accelerates aluminium corrosion at the contact interface, particularly in wet environments. Our tin-plated AL/CU-rated split bolts use tin as a neutral intermediate surface between the aluminium conductor and copper body, preventing galvanic corrosion and meeting UL 486A-486B aluminium connector requirements.

Q4. What torque should be applied to split bolt connectors?

Torque requirements vary by connector size. As a general guide: small connectors (#14 AWG to #2 AWG) require approximately 15–25 in-lb (1.7–2.8 N·m); medium connectors (#1/0 to 250 kcmil) require 35–60 in-lb (4.0–6.8 N·m); large connectors (350 kcmil to 1000 kcmil) require 80–120 in-lb (9.0–13.6 N·m). Always refer to the specific connector’s installation instructions — over-tightening can fracture the bolt or damage the conductor strands.

Q5. Are insulating covers required on split bolt connectors?

The NEC (National Electrical Code) and most electrical safety standards require that all live conductors and exposed connections be insulated or guarded. Split bolt connections made with a bare (uninsulated) split bolt must be taped with self-amalgamating or PVC electrical tape to at least the equivalent insulation rating of the conductors being joined. Pre-insulated split bolt connectors with snap-on polymer covers eliminate the taping step and provide a more consistent, code-compliant result.

Q6. What is the current-carrying capacity of copper split bolts?

The current capacity of a split bolt connection is limited by the ampacity of the conductors being joined, not the split bolt itself — a properly installed ETP copper split bolt introduces negligible resistance (typically <1 µΩ) above that of an equivalent length of solid conductor. For this reason, split bolts are rated by conductor size range (e.g., 2/0 AWG to 350 kcmil) rather than by ampere rating. The conductor ampacity per NEC Table 310.16 or equivalent national standard governs the maximum current.

Q7. What conductor types are compatible with your line taps?

Our parallel groove line taps are compatible with: solid and stranded copper conductors (THWN, THHN, XHHW, USE-2); all-aluminium conductors (AAC, AAAC); aluminium conductor steel reinforced (ACSR); compact and compressed stranded conductors; and copper-clad aluminium (CCA). Confirm conductor type and size when ordering to ensure the correct groove geometry is supplied — AAC conductors require wider groove spacing than equivalent copper conductor cross-sections.

Q8. Do you supply split bolts with UL listing certification?

Our split bolts are manufactured to UL 486A-486B dimensional and performance criteria and can be supplied with third-party test reports. For products requiring official UL Listing marks (for use in jurisdictions requiring AHJ-approved listed equipment), UL file listing can be arranged for specific SKUs through our testing laboratory partnerships. Please advise at time of enquiry if UL Listing is a hard requirement for your project or distribution programme.

Q9. What is the difference between hot-line taps and standard line taps?

Hot-line taps (also called live-line clamps or hot-stick connectors) are specifically designed for installation on energised (live) overhead conductors using insulated hot sticks — without de-energising the line. They feature: (1) captive bolts that cannot fall if dropped; (2) a conductor groove geometry that allows insertion without the conductor sliding along the main line; (3) stainless steel hardware for corrosion resistance in outdoor exposure; and (4) torque-controlled bolts that achieve correct contact pressure without over-tightening. Standard line taps are installed with conductors de-energised using conventional spanners.

Q10. Can copper line taps be used underground?

Yes. For direct-buried underground distribution (UD) applications, copper H-tap connectors are typically used with either a pre-applied silicone grease fill or an over-moulded insulating cover rated for direct burial. The connector body itself in ETP copper is highly resistant to soil corrosion. For submarine or water-immersed applications, tin-plated copper connectors with epoxy-resin encapsulation are recommended. Always specify the installation environment (direct burial, in-conduit, submersible, or aerial) when ordering.

Q11. What is your minimum order quantity for copper split bolts?

For standard sizes (AWG #6 to 4/0), MOQ is typically 500–1,000 pieces per size. For large conductor sizes (250 kcmil and above), MOQ is 200–500 pieces. Sample quantities (25–50 pieces) are available for testing and approval. Volume discounts apply for orders above 5,000 pieces per size. Contact our copper products sales team for current pricing tiers and packaging options.

Q12. Do you offer custom engraving or marking on split bolt connectors?

Yes. Embossed or laser-engraved markings including: size designation (e.g., “2/0-350”), AL/CU rating indicator, manufacturer code, UL certification mark, and customer part numbers can be applied to the connector body. Minimum quantities for custom marking typically apply. Die stamping (embossed markings) has no additional tooling cost for standard size markings; laser engraving has a one-time setup fee for custom logos or text.

Q13. What packaging is available for export shipments of copper split bolts?

Standard packaging: individual polybag with label per connector, packed 25–100 pieces per inner box, multiple inner boxes per export carton. Heavy-gauge cardboard cartons with moisture-barrier liner protect against tarnishing during sea freight. For distributor requirements, we offer retail blister card packaging, UPC-barcoded inner boxes, and bulk reel/box formats for high-volume users. Custom packaging per distributor planogram or retail shelf specification is available with minimum order commitment.

Contact Cable Glands India at sales@cableglandsindia.com to request a quote for Copper Split Bolts or Copper Line Taps. Please specify conductor size range, Al/Cu or Cu/Cu rating, quantity, and destination port.

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