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Horizontal Boring Tool - GRUNDOMAT®

Grundomat pneumatic piercing tools have been providing accurate horizontal bores beneath roads, railways, and landscaping across North America and around the world for nearly 45 years. Water, gas, sewer and electrical industries have all benefited from this work horse of trenchless technology. Minimal operating space is required and the tool serves as a complement, and in many situations an economical alternative to, larger, more expensive directional drilling equipment.
Reciprocating stepped head keeps tool on target.
Hardened alloy steel chisel for long working life.
All modular construction.
Teflon®* seals and tapes eliminate metal to metal contact and provide for easy user maintenance.

What it Does

Horizontal boring tool Grundomat can perform accurate horizontal bores from 50 to 150 feet in length. The Grundomat can be used in all displaceable soils: sand, loam and even gravel and is easily configured to pull in a wide variety of new pipe materials.

How it Works

Compressed air repeatedly propels the piston against the rear of the chisel head assembly. This first compresses the pre-tensioned steel spring which forces the chisel head assembly forward independently of the main casing to provide a pilot bore. Then, the same continuous force thrusts the main casing ahead. With decades of proven performance, the Grundomat’s patented stepped-cone head consistently provides accurate results.

grundomat horizontal bore in action Reciprocating stepped-cone head

GRUNDOMAT® Hammers Straight Ahead of Conventional Tools

Fixed head "conventional" piercing tools have a tendency to take the line of least resistance when encountering difficult soils and obstacles in their bore path. When they hit an obstruction, they're easily knocked off-course... resulting in a failed bore.

The reciprocating stepped-cone chisel head action of the Grundomat tool is unique because it hammers away at solid obstacles. This two-stroke action means that the piston's impact is concentrated on the reciprocating tool head for optimum boring performance.


  • Reverse Made Easy: 5- through 7-inch diameter Grundomats are equipped with a new patented reverse mechanism. You can easily reverse the Grundomat during the bore, by adjusting a lever on the lubricator control system. There is no need to turn the air hose or stop the tool.
  • Easily launched by hand or from cradle
  • Patented reciprocating stepped-cone chisel head
  • Minimal tool setup for fast, profitable work
  • Durable construction means little maintenance

Cost Savings

  • The Grundomat design provides greater target accuracy than traditional tools
  • In just one simple step, the tool performs a bore and pulls in pipe behind it
  • Minimal disruption to traffic, buildings, and other utilities
  • Avoids sizable surface damage and costly restoration required for old trenching methods
  • Accelerated project completion timeline
  • Easy to set up and operate
  • Minimal crew size

Next Step

Contact TT Technologies to see if Grundomat is the right solution for your needs
Read job stories that feature the Grundomat in action