Copper Offset Tongue Lugs — Cable Lugs with Offset Palm

Jamnagar Brass Components is a leading manufacturer and exporter of copper offset tongue lugs — also known as offset palm lugs, offset cable lugs, or reach-through lugs — widely used in electrical switchgear, MCC panels, transformers, and generator termination boards. The offset design positions the palm (tongue/barrel face) at a different plane than the conductor barrel, providing critical clearance in tight panel spaces and enabling clean, unobstructed cable connections where standard in-line lugs cannot be used.

What is a Copper Offset Tongue Lug?

An offset tongue lug has the flat mounting palm offset (shifted laterally and/or angled) relative to the conductor crimp barrel. This geometry allows the cable to approach from one direction while the bolted terminal face aligns to a different plane — typically the busbar or stud terminal face in a switchgear cubicle. The offset can be 15 mm, 22 mm, 30 mm, or custom values, available as right-hand or left-hand offset depending on the application layout.

Copper Grade for Offset Tongue Lugs — Material Standards

Property	UNS (USA)	EN (Europe)	BS (UK)	IS (India)	Value
ETP Copper	C11000	CW004A	C101	Cu-ETP	Min 99.9% Cu, 100% IACS
Electrolytic Cu Bar	C11000	CW004A	C101	IS 191 Grade A	Extruded/forged lug body
Tin Plating	ASTM B545	EN ISO 2093	BS 1872	IS 1359	5–20 µm bright tin

Types of Copper Offset Tongue Lugs We Manufacture

Standard Offset Tongue Lugs (Single Hole Palm)

Single bolt-hole palm lugs with fixed offset for conductor sizes from 16 mm² to 630 mm² (AWG 6 to 1250 kcmil). Standard bolt sizes M6, M8, M10, M12, M16. Barrel bore and crimp zone engineered for standard compression tooling (Burndy, Klauke, Cembre die sets).

Double Hole Offset Tongue Lugs

Two-bolt palm design for high-current conductors (185 mm² to 1000 mm²) where increased bolted contact area reduces contact resistance and meets bus bar bolt pattern requirements in 11 kV and 33 kV switchgear.

Left-Hand and Right-Hand Offset Lugs

The offset direction (left or right when viewed from the barrel end) is specified to suit the cable routing in the panel. We manufacture both orientations, with 15 mm, 22 mm, and 30 mm standard offset distances, and custom offsets on request.

90-Degree and Angle Offset Lugs

For right-angle cable entries into terminal blocks or bus bars, 90° offset lugs direct the cable vertically into a horizontal bus bar connection — common in transformer LV terminal boards and power factor correction panels.

Range-Taking Offset Tongue Lugs

Range-taking barrel design accepts a range of conductor sizes (e.g. 70–120 mm²) in one lug, reducing the number of stock SKUs needed. Compliant with IEC 61238-1 pull-out and resistance test requirements.

Applications of Copper Offset Tongue Lugs

• MV/LV switchgear and motor control centre (MCC) panels
• Transformer LV terminal boards and winding connections
• Generator output terminals and AVR connections
• Power factor correction (PFC) panels
• Earthing and bonding bars in substations
• Bus duct and busway terminations
• UPS and battery bank connections
• Industrial control panels (IEC and NEMA)

Why Choose Jamnagar Brass Components for Copper Offset Tongue Lugs?

• Full ETP copper C11000 — 100% IACS conductivity certified
• Precision forging + machining — lug body forged for grain continuity, barrel and palm machined to tolerance
• Tin plating standard — 8–15 µm bright tin per ASTM B545 on all standard lugs
• IEC 61238-1 compliant design — conductor pull-out and contact resistance tested
• Custom offset values — any offset dimension to your drawing
• Wide conductor range — 16 mm² (AWG 6) to 1000 mm² (2000 kcmil)
• ISO 9001:2015 certified — inspection reports and CoC with every shipment
• Competitive pricing — 30–50% cost saving vs. European branded alternatives

Frequently Asked Questions — Copper Offset Tongue Lugs

Q1: What is the purpose of the offset in an offset tongue lug?

The offset displaces the mounting palm laterally relative to the cable barrel axis. This creates clearance between adjacent cable terminations in switchgear cubicles, allows cables to approach from one direction while the bolt face aligns to the busbar plane, and enables clean parallel cable routing in panels where in-line lugs would create crossing or clashing. The offset is particularly important in MCC panels and transformer terminal boards with limited spacing.

Q2: What offset distances are available in your standard range?

Our standard offset distances are 15 mm, 22 mm, and 30 mm measured from the barrel centreline to the palm face plane, available as left-hand and right-hand offset (viewed from the barrel end). Custom offset values from 10 mm to 60 mm can be machined to customer drawings. We also manufacture 45-degree and 90-degree offset lugs for right-angle cable entries to vertical busbars.

Q3: What conductor sizes do your offset tongue lugs cover?

Our standard range covers conductor sizes from 16 square mm (AWG 6) to 1000 square mm (approximately 2000 kcmil). For very large conductors above 630 square mm, double-hole palm designs distribute clamping force and reduce contact resistance. All barrel dimensions are designed for compatibility with standard hexagonal crimp tooling including Burndy MD series, Klauke, and Cembre die sets.

Q4: Are your offset tongue lugs tin-plated as standard?

Yes. All our standard copper offset tongue lugs are supplied with 8 to 15 micron bright tin plating per ASTM B545 and EN ISO 2093. Tin plating prevents copper oxidation, improves contact conductivity at the busbar interface, and facilitates installation in damp or humid switchgear environments. Heavy tin plating of 20 to 25 microns for aggressive industrial or coastal environments is available on request.

Q5: What compression tooling is compatible with your offset lugs?

Our barrel dimensions are designed for standard hexagonal crimp tooling: Burndy MD6 through MD750 die series, Klauke 50 to 630 square mm dies, and Cembre HT series. The barrel wall thickness and internal profile conform to IEC 61238-1 tooling fit requirements. Die codes for the specific conductor size and tool brand can be marked on the barrel for field reference if required.

Q6: Do you supply bi-metallic offset tongue lugs for aluminium conductors?

Yes. Bi-metallic offset lugs with a copper or tin-plated copper palm and friction-welded aluminium barrel are available for aluminium conductor to copper busbar connections. The friction-welded Al-Cu interface eliminates galvanic corrosion risk at the joint. These are commonly used where aluminium winding cables from transformers or generators connect to copper terminal bars in switchgear.

Q7: What is the IEC standard for cable lugs and how do your products comply?

IEC 61238-1 is the international standard for compression and mechanical connectors for power cables. It specifies conductor pull-out force tests, contact resistance measurements before and after thermal cycling, and current-carrying capacity requirements. Our offset tongue lug designs are dimensioned and specified with reference to IEC 61238-1 and we can provide test data from accredited third-party laboratories for customers requiring formal type test compliance.

Q8: What bolt sizes are available on the palm of offset tongue lugs?

Standard palm bolt hole sizes are M6, M8, M10, M12, M16, and M20 for metric busbars, and 1/4 inch, 5/16 inch, 3/8 inch, 1/2 inch, and 5/8 inch for NEMA and ANSI busbar bolt patterns. Double-hole palms are available with 1-5/8 inch or 3-1/8 inch centre spacing conforming to NEMA two-hole pad patterns for transformer LV terminals. Custom hole patterns are also available.

Q9: Can you supply offset tongue lugs suitable for 11 kV or 33 kV switchgear?

Yes. Our offset tongue lugs are suitable for use in 11 kV, 33 kV, and 66 kV switchgear when installed with proper creepage and clearance between adjacent lugs per IEC 62271-200 or IEEE C37.20.2 requirements. The lug body is made from ETP copper with tin-plated palm; insulation sleeves or heat-shrink covers are recommended in high-voltage panels to meet creepage distance requirements.

Q10: What is the lead time for copper offset tongue lugs?

For standard sizes 16 to 240 square mm with standard offsets in our stock range: ex-stock delivery in 5 to 7 working days. For non-standard conductor sizes, custom offset distances, or special plating: 2 to 3 weeks. For new custom designs requiring tooling: 4 to 6 weeks including first-article approval. Air freight to the USA typically adds 3 to 5 business days. Sea freight consolidation is available for large orders.