How to Crimp Irreversible Compression Grounding Connectors (C-Taps, Figure 6, Figure 8)
Sep 01, 2026
An irreversible compression grounding connection is only as good as the crimp. The procedure below covers the three connector families in our Irreversible Compression Grounding collection — C-taps, Figure 6, and Figure 8 ground rod connectors — and applies equally to the Burndy HYGROUND classes they cross to.
1. Tooling
- Tool: 12-ton hydraulic crimper with U-style die seats — remote-head pump-and-head sets or battery in-line tools (Burndy Y46/Y750/PAT750 class, Milwaukee M18™ FORCE LOGIC™ 12T, Greenlee EK1240 and equivalents). Smaller 6-ton tools do not develop the force these connectors are qualified with.
- Dies: every connector body is stamped with a die index number. Install the matching U-die pair and nothing else — die substitution is the most common cause of rejected joints.
- Hand tools: wire brush (copper or stainless — never one used on aluminum), cable cutter, tape measure, marker.
2. Prepare the conductors
- Cut conductors square. Do not nick strands.
- Brush every contact surface to bright metal: the cable strands, the rod surface, and the connector bores. Buried conductors oxidize; the crimp needs clean copper to cold-weld.
- Verify range: the run conductor and the tap conductor (or rod diameter) must each fall inside the range stamped on the connector. If either is outside the range, change connectors — never shim, never double-up strands.
3. Seat the connector
- C-tap: hook the C over the uncut run conductor, lay the tap conductor into the smaller saddle alongside it. The tap should extend slightly past the connector ends.
- Figure 6: slide the run conductor through the run bore; insert the tap fully so it is visible past the far end of the tap bore.
- Figure 8: drive the ground rod to final depth first, then slip the rod bore over the rod and lay the grounding conductor in the cable bore, leaving conductor tail past both ends of the sleeve.
4. Crimp
- Center the die on the first crimp position. Where the connector carries crimp-position marks, follow them; otherwise make the first crimp at the middle of the barrel and work outward toward the ends, alternating sides. Working outward lets displaced metal flow out rather than trapping it.
- Cycle the tool until the dies fully bottom (metal-to-metal die closure) and the pressure relief fires. A partial stroke is not a crimp.
- Make the full number of crimps for the connector length — on these grounding sleeves that is typically two to four overlapping crimps covering the barrel. Adjacent crimps should touch or slightly overlap; leave no uncompressed band wider than the die.
- Flash (thin fins of extruded metal at the die parting line) is normal. Heavy flash can be dressed with a file; do not saw or grind into the crimp body.
5. Inspect — and what inspectors look for
- Die index embossment: the die stamps its index number into each crimp. A joint with no legible embossment cannot be verified and gets cut out.
- No cracks in the connector body; hairline flash lines are acceptable, fractures are not.
- Conductor tails still visible past the connector ends (proves full insertion).
- Tug test on the tap conductor — no movement.
Because the joint is irreversible, a bad crimp is corrected one way: cut the connector out, re-strip, and install a new one. Order spares accordingly — a 5% overage on connectors is standard estimating practice on grid work.
Burial and encasement
Connectors listed for direct burial and concrete encasement (UL 467) need no coating or access box — backfill or pour directly, per NEC 250.68(A) Exception. In corrosive soils, specs sometimes call for a bitumastic overcoat; follow the project spec, not habit.
Background on where and why this connector class is used — code basis, listings, and how it compares with exothermic welding — is covered in the companion piece: Irreversible Compression Grounding Connectors: Where, How, and Why. For die charts, submittal datasheets, or project quantities, contact the trade desk.
