Grundomat-P Piercing Tool

TT Technologies Introduces New Version of the Grundomat Piercing Tool

The latest version of the Grundomat pneumatic piercing tool from TT Technologies, Aurora, Illinois, is now available. The new Grundomat-P version includes several advancements. Development of a more advanced reciprocating stepped cone chisel head assembly has increased the tool’s effectiveness and a new automatic reverse makes it easier to use.

Stepped Cone Chisel Head

Grundomat-P Piercing Tool

The reciprocating stepped cone chisel head assembly hammers through obstructions, keeping the Grundomat piercing tool on track and on target.

Conventional fixed head piercing tools have a tendency to follow the path of least resistance. When faced with obstacles or difficult soils, conventional tools are often knocked of course. The uniquely designed reciprocating stepped-cone chisel head of the Grundomat powers through obstacles.

The stepped-cone chisel head assembly employs a two-part process. First, the piston strikes the chisel head, propelling it forward. The chisel head creates a pilot bore for the rest of the tool to follow. Second, the piston strikes the tool casing propelling the tool forward in to the newly created pilot bore. To reduce wear and maintenance, Teflon™ seals (not plastic) are used to ensure no direct metal-to-metal contact between the piston and internal casing.

The reciprocating stepped cone chisel head assembly on the new Grundomat-P has been redesigned to allow greater surface area contact between the piston and the chisel head. This greater surface area provides even more power to the chisel.


The overall weight of the Grundomat-P version has decreased compared to older models. The overall piston weight, however, has been increased, giving the Grundomat-P version greater impact power. This greater impact power gives the tool more power to bore through tough obstructions faster and more accurately than ever before.

The combination of greater impact power and the redesigned step cone chisel head assembly is improved directional stability, reduced soil friction and higher boring speed, even in the most challenge soil conditions.

Reverse Made Easy

Grundomat-P Piercing Tool

By adjusting a lever on the in-line lubricator, the Grundomat can be easily reversed, during the bore.

In addition, 5- through 7-inch diameter Grundomat-P models are equipped with a new patented reverse mechanism. The Grundomat-P is easily reversed, during the bore, by adjusting a lever on the lubricator control system. Smaller Grundomat models are reversed by simply turning the air a hose quarter turn.

Lubricant for the Grundomat is fed to the tool through an in-line lubricator. The lubricant, Grundo-Oil, is specially formulated for pneumatic tools and is both biodegradable and environmentally friendly.

Piercing Tool Applications

The Grundomat is ideal for water, sewer, landscape and irrigation, gas, electrical and plumbing contractors. Grundomat piercing tools are easily launched by hand, or from a starting cradle. The tools can be used to pull steel or plastic pipe, or drive steel pipe. The tools are also easily configured for pipe pushing (extraction) applications. During pipe extraction, a pipe-pushing adapter is placed on the front of the piercing tool. The tool’s percussive force is then used to literally drive out an existing service line.

There are twelve Grundomat models ranging in diameter from 1 3/4 inches to 7 inches. A full line of accessories, including aim and launch equipment, as also available. Grundomat tools and accessories are available in packages or individually. Because of their simple design, all Grundomat tools are field repairable.

Utility Products Showcase, April 2000