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Two-Hole Copper Lugs

AD two-hole copper cable lugs and CL-2H two-hole copper tube lugs for bolting large copper conductors to busbars and equipment pads.

Fast answer: Two-hole lugs use two bolt holes on the palm so the connection cannot rotate on a busbar or terminal pad. VoltixC groups two copper series here: AD two-hole copper cable lugs and CL-2H two-hole copper tube lugs. Confirm hole spacing, bolt size and conductor size, then request a quotation.

The supplier specification sheets behind this page list 66 part numbers, from a 6 AWG (16 mm²) tube lug up to an 800/1000 kcmil (500 mm²) cable lug, all in tin-plated copper. Each row gives the stud hole, the hole spacing, the barrel inside and outside diameter and the overall length in mm, so you can match a lug to a busbar before you ask for a quote.

Two-Hole Copper Lugs: AD series straight two-hole copper cable lug
  • 2 copper series: AD and CL-2H
  • 66 listed part numbers: 12 AD and 54 CL-2H
  • 6 AWG to 800/1000 kcmil (16 to 500 mm²) conductor sizes on the specification sheets
  • 25.4, 44.5 or 45 mm between the two bolt holes, by series and size
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What are two-hole lugs, and why do they stay put on a busbar?

A two-hole lug is a cable lug whose flat palm has two bolt holes side by side, so two bolts clamp it to the busbar or equipment pad instead of one. With a single bolt, the palm can pivot around that bolt while the nut is tightened or when a stiff cable pushes against it. A second bolt removes the pivot. Catalogs also list it as 2 hole crimp lugs, double hole cable lugs or 2 hole terminal lugs, and each of those names means the two-bolt palm described here.

Buyers on trade forums ask the same thing in practical terms: whether a two-hole lug should go wherever the bus bar is drilled for two holes, and whether a one-hole lug on a larger wire size twists when it is tightened. The answer on this page comes from the part itself: the two-bolt palm described above has no single pivot, and the steps below show where that matters.

How a two-hole copper lug joint is made:

  1. The stripped conductor goes fully into the barrel, the round tube end of the lug.

  2. The barrel is crimped with a die matched to that lug and that conductor size.

  3. The flat palm is laid over the two drilled holes on the busbar or pad.

  4. Two bolts go through both holes and are tightened to the equipment maker’s torque value.

  5. With both bolts in, the palm stays square to the pad and the cable leaves in the direction it was set.

Caution

A joint that turns while it is tightened can press the cable against a neighboring phase or the cabinet wall, and a palm that is not flat on the pad has less contact face. Both problems start at step 4, and a second hole is the fix for them on large, stiff conductors.

Heat is the other question buyers raise. Installers on one forum thread tie two-hole lugs, long barrels and die-type crimps to current that flows for months or years, as against the short, occasional current on grounding and bonding joints. This page does not turn that into a sizing rule: the equipment maker’s terminal instructions decide which lug form a joint needs.

Two-hole lugs by series: AD and CL-2H model tables

VoltixC lists 66 two-hole lugs in two copper series: 12 AD two-hole copper cable lugs and 54 CL-2H two-hole copper tube lugs. Both tables run from the smallest conductor to the largest and give the stud hole, the hole spacing, the barrel diameters and the length from the supplier specification sheets. Every listed row is tin-plated copper.

AD Two-Hole Copper Cable Lugs

The AD series is a two-hole copper cable lug with a straight palm in the series photo. It reaches the largest conductors on this page, from 2 AWG (38 mm²) to 800/1000 kcmil (500 mm²). Hole spacing steps from 25.4 mm on AD38 to AD150 up to 44.5 mm from AD185 upward, where the stud hole also grows to 14 mm.

AD Two-Hole Copper Cable Lugs: two-hole copper cable lug with a straight palm
Part No.AWG / kcmilmm²Stud hole Ø (mm)Hole spacing (mm)Barrel ID d (mm)Barrel OD D (mm)Length L (mm)
AD382 AWG38925.49.511.765.8
AD601/0 AWG601125.411.914.474.7
AD803/0 AWG801125.414.917.982.3
AD1004/0 AWG1001125.416.820.186.6
AD125-10—1251125.417.821.389.7
AD150250/300 kcmil1501125.419.623.494.5
AD185300/350 kcmil1851444.521.125.3117
AD200400/500 kcmil2001444.522.527119.6
Show the other 4 rows: AD250, AD325, AD400, AD500
Part No.AWG / kcmilmm²Stud hole Ø (mm)Hole spacing (mm)Barrel ID d (mm)Barrel OD D (mm)Length L (mm)
AD250400/500 kcmil2501444.525.230.2120.7
AD325500/600 kcmil3251444.527.633.1130.2
AD400600/750 kcmil4001444.531.838.2136.8
AD500800/1000 kcmil5001444.535.642.7147.5

Source: per supplier specification sheet (AD series); values as printed, not individually re-tested. The sheet gives conductor size in mm²; the AWG / kcmil column comes from the supplier’s product titles, and AD125-10 has no AWG entry.

CL-2H Two-Hole Copper Tube Lugs

CL-2H is the two-hole branch of the CL copper tube-lug range. Compared with AD, it covers smaller conductors: 6 AWG (16 mm²) to 400/500 kcmil (250 mm²). Every CL-2H part number has the same 45 mm hole spacing, and the suffix after 2H sets the stud hole, from 6.4 mm on a -6 part to 17 mm on a -16 part.

Two-Hole Copper Lugs: CL-2H series long-barrel tinned copper two-hole tube lug
Part No.AWG / kcmilmm²Stud hole Ø (mm)Hole spacing (mm)Barrel ID d (mm)Barrel OD D (mm)Length L (mm)
CL14-2H-6 to -126 AWG166.4 / 8.4 / 10.5 / 13455.88.8117.5
CL22-2H-6 to -124 AWG256.4 / 8.4 / 10.5 / 13457.711.3119.2
CL38-2H-6 to -122 AWG356.4 / 8.4 / 10.5 / 13459.812.4120
CL60-2H-6 to -141/0 AWG606.4 / 8.4 / 10.5 / 13 / 15451114130
CL70-2H-8 to -142/0 AWG708.4 / 10.5 / 13 / 15451215130
CL80-2H-8 to -143/0 AWG808.4 / 10.5 / 13 / 15451316130
CL95-2H-8 to -143/0 AWG958.4 / 10.5 / 13 / 154513.517.4132
CL100-2H-8 to -163/0 AWG1008.4 / 10.5 / 13 / 15 / 17451418132
Show the other 5 rows: CL125-2H-10 to -16, CL150-2H-10 to -16, CL180-2H-10 to -16, CL200-2H-10 to -16, CL250-2H-10 to -16
Part No.AWG / kcmilmm²Stud hole Ø (mm)Hole spacing (mm)Barrel ID d (mm)Barrel OD D (mm)Length L (mm)
CL125-2H-10 to -164/0 AWG12010.5 / 13 / 15 / 17451620135
CL150-2H-10 to -16250/300 kcmil15010.5 / 13 / 15 / 17451722150
CL180-2H-10 to -16300/350 kcmil18510.5 / 13 / 15 / 174518.223150
CL200-2H-10 to -16350/400 kcmil20010.5 / 13 / 15 / 17452026150
CL250-2H-10 to -16400/500 kcmil25010.5 / 13 / 15 / 17452228150

Source: per supplier specification sheet (CL-2H series); values as printed, not individually re-tested. Each row groups one conductor size by stud hole suffix; 54 part numbers in the full specification table — request the complete list with your quote.

Spec note

How to read these tables: all values are in mm and come from the supplier specification sheets, not from VoltixC re-testing. The sheets label every size A.W.G.; US practice states sizes above 4/0 AWG in kcmil, so entries from 250 upward are shown here as kcmil. A paired entry such as 400/500 names the two conductor sizes listed against one lug. Values on your approved drawing are the ones an order is made to.

Some AWG sizes carry more than one part number because the sheets size each barrel in mm². AD200 (200 mm²) and AD250 (250 mm²) are both listed at 400/500 kcmil, and CL80-2H, CL95-2H and CL100-2H are 80, 95 and 100 mm², all at 3/0 AWG. Pick by the mm² size of your conductor, or send its outside diameter with your enquiry.

How to choose two-hole lugs: conductor, spacing and bolt checks

Choose two-hole lugs by conductor size first, then check hole spacing, bolt size and barrel fit against the equipment you are bolting to. The model tables give the conductor size, stud hole, hole spacing and barrel for every listed part number; your busbar drawing gives the other side of each check.

CheckWhat to measure or readWhere the answer comes from
Conductor sizeAWG or kcmil on the cable jacket, plus the strand classModel tables above: AWG / kcmil and mm²
Hole spacingCenter-to-center distance between the two holes on the busbar or padModel tables: 25.4 or 44.5 mm on AD, 45 mm on CL-2H
Bolt and hole sizeBolt diameter used on the busbar or ground plate, and the clearance hole it needsModel tables: stud hole 9 to 14 mm on AD, 6.4 to 17 mm on CL-2H
Barrel and dieBarrel diameters and the crimp die your tool takesBarrel ID and OD in the model tables; die matched to lug and conductor per order
Pad width and clearancePalm width against pad width, and room for two bolt headsYour drawing and equipment photos
PlatingTinned or bare copper surfaceTin on every listed row; another finish is not on the current list, so ask before you specify it

A request for a NEMA 2 hole lug points to one spacing figure: 3M states that the center-to-center spacing of its two-hole mounting holes meets the NEMA standard of 1.75 in (44.5 mm). The same 1.75 in spacing appears in 3M’s selection table for its two-hole 40000 Series. For hole size, CMC gives one example: a 0.562 in mounting hole for 1/2 in bolts on its AHL400-2 aluminum two-hole lug. These are other makers’ published values; on the VoltixC sheets, AD185 to AD500 list the same 44.5 mm between hole centers; AD38 to AD150 list 25.4 mm, and every CL-2H part lists 45 mm. The sheets do not name NEMA, so check the spacing column against your busbar rather than a NEMA label.

Tip

Measure the busbar, not an old lug. A worn or re-drilled lug can mislead you about both spacing and hole size, while the busbar holes are what the new lug has to match.

Tip

When a cable falls between two listed entries, send the conductor construction and outside diameter with the size. A fine-stranded or flexible conductor of the same nominal size can need a different barrel than a standard stranded one, and that choice is confirmed per order.

What are AD and CL-2H two-hole copper lugs made of?

Every AD and CL-2H part number is listed with a tin-plated copper body. The supplier documents describe the copper differently by series:

  • The CL-2H series summary lists red copper with more than 99% copper content and tin plating.
  • The AD specification sheet gives copper for the body and tin for the plating, and names no copper grade.
  • In both series, the sheets give hole spacing, stud hole, barrel diameters and length in mm; barrel wall and palm thickness are not listed, so ask before you specify them.

Two-hole copper tube lugs are made from a length of copper tube. The round end stays as the barrel that takes the conductor, and the other end is flattened into the palm and pierced with two bolt holes. Your drawing has to fix the barrel wall thickness, and any palm width or hole position that differs from the sheet.

Which copper stock standard applies depends on the product form. EN 13601, for one, covers copper rod, bar and wire for general electrical purposes and sets sampling procedures and test methods for checking conformity. Naming the standard here is not a claim that VoltixC stock is certified to it; the copper grade is confirmed per order, but no stock standard is stated in the supplier data, so ask before you specify one.

Two-hole lugs or another lug: which route fits your connection?

Two-hole copper lugs suit a copper conductor bolted to a pad with two drilled holes. An aluminum conductor, a single stud, a narrow pad or a panel built to DIN sizes each sends you to a different page in the same copper cable lug range, and the table lists each route with the page that covers it. Two-hole compression lugs with color-coded barrels, such as brown or blue for the matching die, sit on their own page; the AD and CL-2H lugs here carry no color code.

RouteWhat the part isPick it whenWhere to look
Two-hole copper lugs (this page)AD and CL-2H copper lugs, 2 bolt holes, 6 AWG to 800/1000 kcmil as listedCopper conductor; busbar or pad drilled for two boltsModel tables above
Two-hole compression lugsCopper and aluminum two-hole lugs with color-coded barrels matched to die colorsAluminum conductor, or your crews work by die colortwo-hole compression lugs
One-hole compression lugsCopper and aluminum lugs with a single bolt holeThe terminal has one stud, or the space fits only one boltone-hole compression lugs
Tinned copper tube lugsTinned copper tube lugs across five seriesA tinned tube lug outside the AD and CL-2H rowstinned copper tube lugs
Narrow-palm copper lugsCopper lugs with a narrowed palm or tongueBreaker or terminal pads narrower than a standard palmnarrow-palm and narrow-tongue lugs
DIN 46235 copper lugsMetric compression lugs sized to DIN 46235Panels and drawings specified in mm² to DIN sizesDIN 46235 cable lugs

Other lug makers publish two-hole ranges in the same size band. As one example, 3M lists two-hole models in its 40000 Series from 1/0 AWG through 1000 kcmil, and its 31000 Series includes two-hole long-barrel lugs for 6 AWG through 1000 kcmil. Burndy’s two-hole copper compression range has a two-hole standard-barrel form, identified as YA-2L, next to its other barrel types. Those figures belong to those makers; for AD and CL-2H, use the spans in the model tables.

Four cases call for another lug page.

  • For an aluminum conductor, go to the two-hole compression lug page; the AD and CL-2H rows list copper bodies only.
  • A pad with one stud or one hole calls for a one-hole lug from the start, because a two-hole palm can’t be bolted down with one bolt.
  • Where the enclosure is tight, check pad length for two holes and clearance for two bolt heads, and use a one-hole lug if the equipment space or the allowed cable bend cannot take them.
  • Drawings in mm² to DIN sizes match the DIN 46235 page.

Changing route changes the die and the model numbers, and the hole pattern on your drawing moves with them. Send the busbar drawing with the conductor size, and the route is confirmed per order.

Where do two-hole copper lugs fit, and when should you pick something else?

Two-hole copper lugs fit large copper conductors that bolt to pads drilled for two bolts; they are the wrong choice for single-stud terminals and aluminum conductors. The rows below are application types worked out from the two-bolt palm and the listed sizes. They are not VoltixC project records.

ApplicationNeedsWatch
Switchgear and panelboard busbarsA large copper feeder cable within the listed sizes and a bar drilled for two boltsPhase-to-phase clearance once both bolt heads are in; when the stiff feeder cable pushes on the palm, two bolts hold it square to the bar
Transformer and equipment terminal padsA flat pad with two holes and a conductor inside the AD or CL-2H rowsThe cable bend from the pad to the tray; a long barrel adds length before the cable can turn
DC busbars in battery rooms and UPS cabinetsLarge copper cable bolted to a flat bar, and a bar that must not twist when someone moves a heavy cableBar thickness and bolt length, both taken from the cabinet drawing
Stacked terminationsRoom for two lugs on one set of holes; the AD and CL-2H series photos show straight palms, so any stacking fit is confirmed per orderMatched offsets: CMC describes offset heights and pad dimensions that let its ATL lugs stack on its AHL lugs, joining two conductors at each NEMA two-hole spade position
Single-stud or single-hole terminals (not a fit)Two holes to bolt through, and a single stud gives only oneStart with a one-hole lug; the FAQ below explains why cutting one hole off is not the fix
Aluminum conductors (not a fit)An aluminum lug, because the AD and CL-2H rows are copper bodies onlyThe two-hole compression lug page linked in the route table carries aluminum lugs
Grounding and bonding jumpers (check first)The lug form set by the grounding design and the equipment maker’s instructionsA ground bar drilled for one bolt falls under the single-hole row above; one drilled for two can take an AD or CL-2H size, quoted for the jumper conductor

The three limit rows are the short form of the route table above, which links each of those lug pages. If your joint is in none of the seven rows, send the pad drawing and the conductor size with your enquiry, and the fit is checked against that drawing.

What can you check before buying two-hole lugs from VoltixC?

You can check three things before ordering: the certificate images, the machines in the factory photos and the answers to four supplier questions. VoltixC is an industry-and-trade business with its own plant in Guangzhou: a 1,200 m² factory, 25 staff and 135 production machines.

The CE attestation covers the full VoltixC terminal range, AD and CL-2H included: it is issued under the Low Voltage Directive 2014/35/EU against EN 60947-7-1, EN 60947-7-2 and EN 60947-7-3. VoltixC is UL certified. RoHS test report available (SGS): lead, mercury, cadmium and hexavalent chromium were tested to EU RoHS limits on tin-plated copper terminal samples. All three documents name Guangzhou FuTeXin Technology Co., Ltd., the company behind the VoltixC brand. Numbers and dates are not printed here; ask for the documents with your quote.

  • VoltixC CE attestation under the Low Voltage Directive 2014/35/EU
  • VoltixC UL certified document
  • VoltixC RoHS test report (SGS)

The photos below were taken on the Guangzhou floor. Each shows a machine that is there; none of them is a test result for an AD or CL-2H model.

  • 25-ton high-speed stamping press at VoltixC
    Photo: a 25-ton high-speed stamping press.
  • Second 25-ton high-speed stamping press at VoltixC
    Photo: a second 25-ton high-speed stamping press.
  • Precision wire-cut EDM machine at VoltixC
    Photo: a precision wire-cut EDM machine in the tool room.
  • CNC milling machine at VoltixC
    Photo: a CNC milling machine in the tool room.
  • Material tensile testing machine at VoltixC
    Photo: a material tensile testing machine.
  • Temperature-rise tester at VoltixC
    Photo: a temperature-rise tester.
  • Optical coordinate measuring machine at VoltixC
    Photo: an optical coordinate measuring machine.

Put these four points to each two-hole lug source you compare, then set the answers side by side:

  1. Which hole spacing and hole diameter will be on the approved drawing, and in which unit?
  2. What crimp die and tool does the barrel take for my conductor size and strand class?
  3. Is the surface tinned or bare, and which copper grade and stock standard apply?
  4. Which certificate applies to the model I am buying, and can I see its scope page?

Naming EN 13601 or another maker’s NEMA figure on this page is not a claim that AD or CL-2H parts are certified to them; the CE, UL and RoHS documents above are the ones on file.

What sets the price of two-hole lugs, and what should your quote request include?

The price of two-hole lugs follows the copper in the part and the work done to it: conductor size, series, plating, hole pattern, quantity per model and packing. No prices are published here. Each line on the quotation is priced against your drawing and size list.

DriverEffect on costWhat you control
Conductor sizeA larger barrel and palm use more copper per pieceThe AWG or kcmil size on each line
Series (AD or CL-2H)Barrel length and form differ between the two seriesWhich series your drawing calls for
PlatingEvery listed row is tin-plated; a different finish is a special requestAny finish other than tin, stated on the enquiry
Hole spacing and hole diameterA pattern that differs from the supplier drawing may need new tooling, confirmed per orderSpacing and bolt size from your busbar
Quantity per modelSet-up is spread over the pieces in each model lineThe piece count for each model you order
Packing and labelsCustom bags, labels or carton marks add handlingYour packing and marking instructions
DocumentsDrawing approval and certificate copies are prepared per orderWhich documents your project file needs

Two of these drivers are fixed once the busbar and cable are chosen: conductor size and hole pattern. The rest are buyer choices, so a quote can be run again with a different finish, pack size or document set without changing the lug itself. When a size list mixes AD and CL-2H models, list each model on its own line so the quotation can price them one by one.

MOQ, warranty and payment terms are confirmed per order by email or the enquiry form. For a first sample of an AD or CL-2H model, VoltixC quotes fastest sampling from 7 days, confirmed per order.

What to send with a two-hole lug enquiry:

  • Part numbers from the tables (with the stud hole suffix on CL-2H), or the conductor size and unit (AWG, kcmil or mm²) for each line
  • Conductor metal, strand class and outside diameter
  • Hole spacing and bolt size from the busbar or pad drawing
  • Finish, if you need anything other than the listed tin plating
  • Quantity per model and any packing or label needs

The enquiry form asks for name, company, email, country, product line, conductor size, quantity and a message. It has no upload field, so send drawings and photos of the busbar to hugo@voltixconnect.com after you submit the form.

Size tools and guides for two-hole lugs

Before you write, the pages below answer the size, form, drawing and crimping questions that come up when two-hole lugs are specified.

  • Cable lug size chart (tool)

    Look up lug sizes against a conductor size in the cable lug size chart.

  • Cable lug types (guide)

    How lug forms differ, and which form suits a given joint, is set out in the guide on how to choose cable lugs.

  • Cable lug dimensions (guide)

    How barrel, palm and hole sizes are read on a lug drawing is covered in the guide to reading cable lug dimensions.

  • Crimping a lug barrel (guide)

    Tool and die choice, stripping, crimping and a pull check are walked through in the guide on how to crimp wire terminals.

The full copper range sits on the cable lugs page.

FAQ about two-hole lugs

Why use a two-hole lug instead of a one-hole lug?

A two-hole lug is bolted at two points, so it cannot pivot on the pad while the nuts are tightened or when a heavy cable is moved. A one-hole lug has a single bolt and can turn around it. Where the busbar or pad is already drilled for two holes, the two-hole palm uses both; the hole spacing for each part number is in the model tables.

What hole spacing do AD and CL-2H lugs use?

AD38 to AD150 list 25.4 mm between hole centers, and AD185 to AD500 list 44.5 mm; every CL-2H part number lists 45 mm. For reference, 3M states that its two-hole mounting-hole spacing meets the NEMA standard of 1.75 in (44.5 mm). The supplier sheets do not name NEMA, so send the center-to-center distance of your busbar holes and compare it with the table.

Are two-hole compression lugs on a different page?

Yes. Copper and aluminum two-hole compression lugs with color-coded barrels matched to die colors are on the two-hole compression lug page. This page holds the AD and CL-2H copper series, which are listed by model number and conductor size without die color codes.

Do two-hole lugs come with an inspection window?

The AD and CL-2H specification sheets show no inspection window, so a window is not on the current list for either series; ask before you specify one. The barrel inside diameter for each size is in the model tables.

Which conductor sizes do the AD and CL-2H series list?

The AD series lists 12 part numbers from 2 AWG (AD38, 38 mm²) to 800/1000 kcmil (AD500, 500 mm²); AD125-10 is listed at 125 mm² only. The CL-2H series lists 54 part numbers over 13 conductor sizes from 6 AWG (16 mm², CL14-2H) to 400/500 kcmil (250 mm², CL250-2H); its entries run 6, 4, 2, 1/0, 2/0, 3/0 and 4/0 AWG, then 250/300, 300/350, 350/400 and 400/500 kcmil. Every row is tin-plated copper, per supplier specification sheet.

Why do some AWG sizes have more than one part number?

The specification sheets size each barrel in mm², and two or three mm² sizes can share one AWG label. AD200 (200 mm²) and AD250 (250 mm²) are both listed at 400/500 kcmil, and CL80-2H, CL95-2H and CL100-2H (80, 95 and 100 mm²) are all listed at 3/0 AWG. Match the mm² size of your conductor, or send its outside diameter with your enquiry.

Does the electrical code require a two-hole lug?

This page does not interpret the electrical code for your installation. The lug type on a switchgear or transformer terminal is set by the equipment maker’s instructions, so check those first and follow them if they name a lug type; the AD or CL-2H model to match is then confirmed per order.

Can I cut one hole off a two-hole lug to fit a single stud?

Avoid it. A two-hole lug cut down to one hole is no longer the part described in the supplier data, so the values on this page stop applying to it. A one-hole lug sized for the stud is the cleaner fix; the one-hole route is in the comparison table above, and the model is confirmed per order.

Are the values in the model tables tested by VoltixC?

No. The part numbers, sizes and dimensions come from the supplier specification sheets as printed and were not individually re-tested. The approved drawing for your order is the document the parts are made to.

Can VoltixC make two-hole copper lugs to my drawing?

Yes. Send the drawing with hole spacing, hole diameter, barrel size and finish, and the part is quoted against it. Fastest sampling is from 7 days, confirmed per order. Changes that need new tooling are confirmed per order before work starts.

Request a quote for two-hole copper lugs

Send your size list, busbar drawing and quantity per model, and a VoltixC engineer checks them against the AD and CL-2H rows. Use email or the enquiry form for the list.

Ask a VoltixC Engineer