Cable Type to Lug Cross Reference: THHN, XHHW, DLO, Welding, Battery and Aluminum
Sep 29, 2026
Purchasing agents buy lugs by gauge. Installers find out on the job that gauge is only half the answer. The stranding class and conductor material of the cable decide which lug family is listed for it. This table is the shortcut.
The rule
UL 486A/B lists a compression lug for a conductor size and stranding class. Class B (concentric, standard building wire) and Class C fit standard lugs. Class I and Class K (fine strand: DLO, welding, battery, locomotive) need flex lugs. Aluminum conductor needs a lug listed AL9CU or an aluminum body lug with joint compound. Get those three things right and the rest is stud size and barrel length.
Cable to lug table
| Cable on the reel | Typical stranding | Conductor | Lug family | Notes |
|---|---|---|---|---|
| THHN / THWN-2 | Class B | Copper | Standard compression lug, copper, tin plated | Feeders, branch circuits, panels. Most common lug on the site. |
| XHHW-2 | Class B | Copper or aluminum | Standard lug (Cu); AL9CU mechanical or aluminum compression lug (Al) | Service and feeder work, solar AC. Check the reel: XHHW-2 aluminum is common on services. |
| USE-2 / RHW-2 | Class B | Copper or aluminum | As above by material | Underground services, solar DC homeruns. |
| PV wire (UL 4703) | Class B or C | Copper (tinned) | Standard lug, tin plated; MC4 at the module end | Combiner and inverter DC landings. Long barrel where the equipment lug space allows. |
| DLO (RHH/RHW-2, 2 kV) | Class I | Tinned copper | Flex / DLO lug listed for the range | Generators, switchgear leads, drives, wind, BESS. Never a standard lug. See the DLO guide. |
| Welding cable | Class K | Copper | Flex lug listed for Class K | Portable equipment, temporary power. Not for building wiring unless listed. |
| Battery cable (SGT, SGX, UL 1426, 2 kV BESS) | Class K | Copper (often tinned) | Battery lug or flex lug for fine strand | Inverter DC, BESS racks, telecom DC plants. Heavy wall, tin plated. |
| MV feeder 5 to 35 kV (EPR, TRXLPE) | Class B | Copper or aluminum | Standard or aluminum compression lug at the termination kit; long barrel typical | Lug sits inside a stress cone termination; follow the kit's lug spec. |
| Bare copper grounding electrode conductor | Class B (or solid to 6 AWG) | Copper | Standard lug, or irreversible compression connector for grounding (Fig 6 style) | Ground bars, rods, bonding. Irreversible connectors for TIA-607 and data center ground rings. |
| Bare or covered aluminum grounding / neutral | Class B | Aluminum | AL9CU dual rated mechanical lug, or aluminum compression with compound | Never copper-only lugs on aluminum. |
Sizing reminders that trip people up
- Same gauge, different diameter. 2/0 DLO will not fit a 2/0 standard barrel. Flex lugs are sized to the fine strand OD.
- Compact stranding. Compact XHHW and some MV conductors are smaller than Class B of the same size. Standard lugs are still listed for them in most sizes; check the lug's compact call-out when it matters.
- kcmil vs MCM. Same thing. 250 MCM is 250 kcmil.
- Two-hole spacing. Two-hole lugs use NEMA hole spacing (1 3/4 inch centers for 1/2 inch bolts on most sizes). Match the bus drilling before you order 500 lugs.
- Long barrel vs standard barrel. Long barrel gives two crimps and more pull-out strength; specify it on 4/0 and larger, on vibration and on anything a QA inspector will pull on. Standard barrel is fine on branch and feeder work where space is tight.
How to order
Send the cable type, gauge, conductor material, stud or bolt size and one or two hole to CS@ConversionsTech.com, or search the Burndy, ILSCO or Panduit number on the site. Every compression lug page shows the conductor range, barrel length, die index and color code. Same-day shipping on in-stock items; case pricing for trade accounts.
Related: DLO lugs vs standard lugs · Cross-reference hub · Trade accounts
