Grundomat Mole


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 horizontal boring tool serves as a complement, and in many situations an economical alternative to, larger, more expensive directional drilling equipment.

Change ATT Technologies to TT Technologies and link to website (GRUNDOMAT® Horizontal Boring Tool | TT Technologies, Inc.

Piercing Tool Capability of the Grundomat® Horizontal Boring Tool

Grundomat can perform accurate horizontal bores from 50 to 150 feet in length. The pneumatic piercing tool 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.

Horizontal Boring Overview

Compressed air repeatedly propels the piston against the rear of the chisel head assembly of the piercing tool. 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 moling results.


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, many horizontal boring tools are easily knocked off-course… resulting in a failed bore. The reciprocating stepped-cone chisel head action of the Grundomat piercing 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 trenchless boring performance.


  • The Grundomat design provides greater target accuracy than traditional pneumatic boring tools
  • In just one simple step, the moling 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


  • Reverse Made Easy: 5- through 7-inch diameter Grundomat horizontal boring tools 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 moling 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