
505-0081
HDD Bits · 11 SKUs
5/6-bolt pattern (12mm/16mm) for Ditch Witch machines
Ditch Witch machines use their own bolt pattern family: a 5-hole 12 mm circle on the JT-series mid-size rigs and a 6-hole 16 mm pattern on the larger JT30 and up. The two are not interchangeable with each other or with Vermeer heads, so contractors running mixed fleets have to keep three bit bins on the truck. Drillworx stocks the full Ditch Witch line so one phone call covers the whole fleet.
The Ditch Witch geometry leans toward a flatter bit face than the typical Vermeer profile, which gives the sidewall more grip during steering — useful on short utility crossings with tight cover. Drillworx's extreme-taper and serrated-carbide variants push that steering authority further without sacrificing penetration rate in standard overburden.
For hard-ground work, the 5-hole 12 mm pattern has a full catalog of carbide-coverage bits that match Vermeer-pattern rock bits shot-for-shot. Expect the same mass, the same hardfacing, and the same service life in comparable formations.
Field guidance
The 5-hole 12 mm pattern covers the majority of residential and commercial utility crossings — gas, water, and fiber in typical overburden.
Step to the 6-hole 16 mm pattern for the bolt shear capacity these rigs demand. Rock-capable geometries are available on this pattern too.
Serrated-carbide Ditch Witch bits hold up better than steel-milled teeth. Budget for more frequent carbide-cutter replacements.
Extreme-taper profiles give the sidewall a bigger bite, letting the locator crew hold line on three-foot cover crossings.
Compatibility
11 products

505-0081

505-0083

505-0089
505-0850
HDD Bits
505-0850
505-0855
HDD Bits
505-0855
505-3970
HDD Bits
505-3970
505-3971
HDD Bits
505-3971
505-4545
HDD Bits
505-4545
505-9101
HDD Bits
505-9101
505-9105
HDD Bits
505-9105

505-9127
FAQ
No. The bolt count, circle diameter, and bolt size are different between the JT mid-size and the JT30-plus heads. A bit drilled for one pattern will not bolt to the other.
In cobbly glacial till, contractors we serve run the serrated-carbide variants on the 5-hole pattern and the Cobble Boss on the 6-hole pattern. Both trade some ROP for a much longer carbide life in hard ground.
Not recommended. Adapter plates add stack height, which changes pitch and sonde geometry. If you run mixed fleets, adapt at the tailpiece with a QuickFire or Firestick crossover rather than at the bit.
Our team maintains inventory across 8 locations. Send us your spec and we'll confirm availability the same day.