Brass Line Taps and Brass Split Bolt Connectors
Brass Line Taps and Brass Split Bolt Connectors are mechanical electrical connectors manufactured from high-conductivity brass alloy, used to tap, branch, or join copper and aluminium conductors without cutting the main run. Manufactured by Cable Glands India, these connectors combine a split-thread brass body with a hex-head bolt to deliver low contact resistance, high mechanical clamping force, and long-term corrosion resistance. Supplied in natural, tin-plated, and nickel-plated finishes, they are used across power distribution, earthing, transformer yards, and industrial wiring installations by electrical OEMs, EPC contractors, power utilities, and distributors worldwide.
Detailed Product Overview
What Are Brass Line Taps and Split Bolt Connectors
Brass Line Taps, commonly referred to as Split Bolt Connectors, are mechanical joining devices used to connect a branch or tap conductor to a continuous main conductor without disturbing the main run. The connector body is machined from solid brass rod and features a longitudinal split-thread bore into which the conductors are inserted side by side. A brass or steel bolt with a hexagonal head is then tightened, compressing the split body and clamping both conductors together in a single low-resistance joint. This design is widely specified in overhead line construction, earthing networks, distribution boards, and industrial panel wiring wherever a secure, reusable, field-installable connection is required.
Split-Bolt Body Design and Clamping Mechanism
The split-bolt body consists of a solid brass block bored to accept two or more conductors of similar or dissimilar cross-section. A saw-cut slot runs through the threaded bore, allowing the bolt to draw the two halves of the body together as it is tightened. This generates a uniform, high-pressure clamping force along the full length of the conductor contact area, rather than a single point contact. The result is a mechanically stable joint with consistent contact resistance, suitable for both permanent installations and connections that may need to be opened and re-terminated during maintenance.
Brass Alloy Composition and Electrical Conductivity
Line taps and split bolt connectors are machined from leaded brass alloys such as CuZn39Pb3 (IS 319 Type I, equivalent to UNS C38500), chosen for their combination of high electrical conductivity, good machinability, and resistance to stress-corrosion cracking. The copper content, typically 57-60%, provides conductivity in the range of 26-28% IACS, sufficient for continuous current-carrying applications when correctly sized to the conductor. The balanced zinc and lead content ensures the alloy can be precision-turned to tight tolerances on CNC lathes without compromising long-term mechanical integrity under clamping load.
Conductor Compatibility – Copper and Aluminium Cables
Brass split bolt connectors are primarily designed for copper-to-copper conductor connections, where the similar electrochemical properties of brass and copper minimise galvanic corrosion risk at the joint. Aluminium-to-aluminium and copper-to-aluminium connections are also supported using bimetallic-rated variants and jointing compounds to suppress oxidation at the interface. Conductor cross-sections handled by our standard range extend from 2.5 mm² for control panel wiring up to 400 mm² for heavy industrial feeders and substation earthing conductors, with intermediate sizes covering distribution board and service-drop applications.
Surface Finish Options – Natural, Tin-Plated and Nickel-Plated Brass
Depending on the installation environment, brass line taps and split bolt connectors are supplied in three standard finishes. Natural (bare) brass is suited to indoor panels and dry environments. Electro-tin plating, typically 8-15 microns thick, improves corrosion resistance and reduces contact oxidation for outdoor, coastal, and high-humidity installations. Nickel plating offers superior hardness and resistance to abrasion and salt-fog exposure, and is preferred for offshore, marine, and heavy industrial environments where connectors are exposed to repeated handling and aggressive atmospheres.
Mechanical Strength and Torque Retention
The clamping bolt is torqued to a manufacturer-specified value to achieve full conductor compression without deforming or fracturing the strands. Brass alloys used in this application exhibit tensile strength in the range of 300-550 MPa, allowing the split body to withstand repeated tightening cycles during commissioning and maintenance without loss of clamping force. Torque retention is verified during batch quality inspection to confirm the connector maintains stable contact pressure under vibration and thermal cycling in service.
Corrosion Resistance in Outdoor and Industrial Environments
Because line taps and split bolt connectors are frequently installed outdoors on overhead lines, transformer structures, and earthing grids, resistance to atmospheric corrosion is a key design consideration. The inherent corrosion resistance of brass, combined with tin or nickel plating where specified, allows these connectors to withstand extended salt-spray exposure, humidity cycling, and UV exposure without significant loss of conductivity or mechanical strength, reducing the frequency of maintenance replacement in exposed installations.
Standards Compliance and Certification Framework
Our brass line taps and split bolt connectors are manufactured to conform with IS 319 Type I material requirements, IS 5561 electrical connector specifications, and IEC 61238 mechanical and compression connector test requirements. Export variants are additionally verified against ASTM B453, DIN 46267, and UL 486A-486B where required by the destination market. Each production batch is accompanied by dimensional, torque, and conductivity test records, and the finished parts are RoHS and REACH compliant for use in regulated markets.
Key Features
- High-conductivity brass body for minimal voltage drop across the joint
- Split-thread clamping design for secure single or multi-conductor joints
- Wide conductor range from 2.5 mm² to 400 mm² (Cu/Al)
- Available in natural, tin-plated and nickel-plated finishes
- Reusable, tool-tightened hex bolt suited to field installation
- Compliant with IS, IEC, DIN and ANSI connector standards
- Corrosion-resistant construction for outdoor, coastal and industrial exposure
- Low, stable contact resistance for long-term network reliability
High-Conductivity Brass Alloy (CuZn39Pb3 / C38500)
The connector body is machined from CuZn39Pb3 brass, internationally recognised under UNS C38500 and EN CW612N designations. This alloy is selected specifically for electrical connector applications because it combines conductivity levels adequate for continuous current-carrying duty with the machinability required to hold tight bore and thread tolerances. The resulting connector delivers consistent contact resistance across production batches, which is essential for utilities and EPC contractors specifying connectors for critical earthing and distribution circuits.
Split-Thread Mechanical Clamping System
Unlike crimped or soldered joints, the split-thread clamping system allows conductors to be inserted and removed without special tooling, making the connector suitable for both new installation and retrofit work. The clamping force is distributed evenly along the conductor length rather than concentrated at a single crimp point, reducing the risk of strand damage. This mechanism also allows conductors of different gauges to be joined within the same connector body, subject to the rated size range.
Corrosion-Resistant Finish Options
Selecting the correct finish extends service life significantly in demanding environments. Tin plating is the standard choice for general outdoor and distribution use, providing a cost-effective corrosion barrier. Nickel plating is specified where connectors are exposed to marine atmospheres, industrial pollutants, or frequent handling, since the nickel layer resists abrasion and maintains a low-resistance contact surface over a longer service interval than tin.
Wide Conductor Range Compatibility
A single product family covers control panel wiring at the small end of the range through to heavy substation earthing conductors and HV bus bar taps at the upper end. This allows EPC contractors and OEMs to standardise on one connector family across a project, simplifying procurement, inventory management, and installation training while maintaining consistent quality and traceability across all conductor sizes used on site.
Reusable Hex-Bolt Fastening
The hexagonal bolt head accepts standard torque wrenches and sockets, allowing installation crews to achieve manufacturer-specified torque values without proprietary tools. Because the connector is not deformed during installation in the way a crimp lug is, it can be opened, inspected, and re-tightened during scheduled maintenance, which is particularly valuable for earthing systems and substation connections that require periodic continuity testing.
Multi-Standard Compliance (IS / IEC / DIN / ANSI)
Export customers frequently require documentary evidence of compliance with more than one national standard. Our line taps and split bolt connectors are produced to meet IS 319 and IS 5561 for the Indian market, IEC 61238 for international mechanical connector requirements, DIN 46267 for the European market, and ANSI C119.4 where connectors are supplied into North American utility projects, allowing a single product line to serve multiple export destinations.
Technical Specifications
| Parameter | Specification |
|---|---|
| Body Material | Brass CuZn39Pb3 (IS 319 Type I) |
| Bolt Material | Brass or Zinc-Passivated Steel |
| Conductor Range | 2.5 mm² – 400 mm² (Cu/Al) |
| Thread Type | ISO Metric, Split-Thread Body |
| Standard Finish | Natural / Tin-Plated / Nickel-Plated |
| Tensile Strength | 300 – 550 MPa |
| Operating Temperature | -20°C to +150°C |
| Contact Resistance | Low and Stable (Batch Tested) |
| Dimensional Tolerance | ± 0.05 mm |
| Plating Thickness | 8 – 15 microns (Tin / Nickel) |
Raw Material Grades
| Grade | Standard | Typical Composition |
|---|---|---|
| CuZn39Pb3 | IS 319 Type I / EN 12164 | Cu 57-60%, Pb 2.5-3.5%, Zn Balance |
| C38500 | ASTM B453 (USA) | Cu 55-60%, Pb 2.0-3.0%, Zn Balance |
| CW612N | EN 12164 (Europe) | Cu 57-59%, Pb 1.6-2.5%, Zn Balance |
| H59 | GB/T 5231 (China) | Cu 57-60%, Zn Balance |
International Equivalent Standards
| Country / Region | Standard / Designation |
|---|---|
| India | IS 319 Type I, IS 5561 |
| Europe | CW612N / CuZn39Pb3 (EN 12164), DIN 46267 |
| USA | UNS C38500 (ASTM B453), ANSI C119.4, UL 486A-486B |
| Japan | JIS H3250 C3771 |
| China | GB/T H59 |
| Russia / CIS | LS59-1 (GOST 15527) |
| International | IEC 61238 |
Product Types / Variants
| Size Designation | Conductor Range (mm²) | Bolt Size | Typical Application |
|---|---|---|---|
| Small | 2.5 – 10 | M6 | Control panels, junction boxes |
| Medium | 10 – 35 | M8 | Distribution boards |
| Large | 35 – 70 | M10 | Power distribution systems |
| Extra Large | 70 – 120 | M12 | Transformer earthing |
| Heavy Duty | 120 – 240 | M16 | Industrial substations |
| Super Heavy | 240 – 400 | M20 | HV transmission & bus bar tapping |
Variant types available: Single-Tap Line Connector, Twin/Multi-Tap Connector, T-Type Line Tap, Parallel-Groove (PG) Style Split Bolt, and Reducing Split Bolt Connector for joining dissimilar conductor sizes. Custom conductor ranges and bolt configurations are available on request.
Applications in Industry
- Overhead transmission and distribution line taps
- Substation and transformer yard earthing grids
- Industrial and commercial electrical panel wiring
- Railway electrification and traction earthing
- Solar and wind power plant earthing networks
- Telecom tower and data centre grounding systems
- Service-drop and distribution board conductor joints
Manufacturing Process
Production begins with incoming inspection of certified brass rod stock, followed by CNC turning to form the split-bolt body and precision boring of the conductor channels. The body is then slotted, threaded, and deburred before proceeding to surface finishing, where parts are either left in natural condition or electroplated with tin or nickel to the specified thickness. Bolts are separately machined and passivated before assembly. Each finished batch undergoes dimensional verification, torque testing, conductivity checks, and salt-spray corrosion testing prior to packing, with full batch traceability maintained from raw material to dispatch.
Quality Standards and Certifications
| Standard / Certification | Scope |
|---|---|
| ISO 9001:2015 | Quality Management System |
| IS 319 / IS 5561 | Material and Connector Specification (India) |
| IEC 61238 | Mechanical and Compression Connector Testing |
| ASTM B453 / ANSI C119.4 | US Market Compliance |
| RoHS / REACH | Environmental Compliance |
| Salt Spray Test (ASTM B117) | Corrosion Resistance Verification |
Why Choose Cable Glands India
- Three decades of manufacturing and global export experience in brass electrical connectors
- In-house CNC machining, plating, and testing facilities for full process control
- Batch-wise dimensional, torque, and conductivity testing with traceable records
- Custom conductor ranges, bolt sizes, and finishes engineered to project specification
- Consistent export packing and documentation for USA, UK, Europe, Middle East, and Africa
- Responsive technical support for EPC contractors, OEMs, and distributors
Indicative Pricing
| Product | Indicative Price | Terms |
|---|---|---|
| Brass Line Taps / Split Bolt Connectors | US$ 12.50 / kg | Ex-Works India; varies by size, finish and order quantity |
Final pricing depends on conductor range, bolt size, plating specification, and order volume. Contact our sales team for a formal quotation.
Frequently Asked Questions
What is a brass split bolt connector used for?
It is used to join or tap electrical conductors mechanically, without cutting the main conductor run, in distribution, earthing, and industrial wiring applications.
What is the difference between a line tap and a split bolt connector?
The terms are largely interchangeable; a line tap describes the functional use of branching a conductor, while split bolt connector describes the physical clamping design used to achieve that connection.
What conductor sizes can these connectors handle?
Our standard range covers 2.5 mm² to 400 mm² for both copper and aluminium conductors, with custom sizes available on request.
Are these connectors suitable for outdoor installation?
Yes, particularly in tin-plated or nickel-plated finish, which provide enhanced corrosion resistance for overhead lines and outdoor earthing grids.
Can brass split bolt connectors join aluminium conductors?
Yes, using bimetallic-rated variants and appropriate jointing compound to control galvanic corrosion at the copper-aluminium interface.
Are these connectors reusable?
Yes, the bolted split-body design allows the connector to be opened, inspected, and re-tightened during maintenance without replacement.
Which standards do your connectors comply with?
IS 319, IS 5561, IEC 61238, ASTM B453, ANSI C119.4, and DIN 46267, depending on the export destination.
Do you provide material and test certificates?
Yes, mill test certificates and batch inspection reports are provided with every shipment.
What is your production lead time?
Standard lead time is 4-6 weeks depending on size, finish, and order quantity.
Do you export internationally?
Yes, we regularly export to the USA, UK, Europe, Middle East, Africa, and Southeast Asia.
Equivalent Terms in Other Languages
| Language | Brass Line Tap | Split Bolt Connector |
|---|---|---|
| Spanish | Conector de derivación de latón | Conector de perno partido de latón |
| Russian | Латунный ответвительный зажим | Латунный соединитель с разрезным болтом |
| French | Connecteur de dérivation en laiton | Connecteur à boulon fendu en laiton |
| Portuguese | Conector de derivação em latão | Conector de parafuso fendido em latão |
| Italian | Connettore di derivazione in ottone | Connettore a bullone spaccato in ottone |
Related Parts and Linked Terms
- Brass Electrical Accessories
- Brass Battery Terminals
- Brass Terminals Blocks
- Tinned Brass Line Taps & Split Bolt Connectors
- Brass Fixed and Swivel Connectors for Flexible Conduits
- Brass Conduit Bushes – Male and Female Brass Bushes
Request a Quote
Share your conductor sizes, quantities, and finish requirements, and our engineering team will respond with a detailed quotation within one business day.
Email: sales@cableglandsindia.com | Phone / WhatsApp: +91-22-43449300 | Website: www.cableglandsindia.com