Split Frame Lathe With Minimal External Components

This patented split frame lathe has minimal external machine components that can reduce pinch points during pipe cutting and beveling operations.


A split frame lathe, otherwise known as "clamshells" because it can open up in half to reassemble around a pipe, is a tool that produces revolutionary cutting or beveling of in-line tube and pipe.  A split frame lathe with internalized protruding components, such as the TRIMAX, is an engineering control that reduces worker injuries and amputations from getting caught in pinch points normally produced by conventional split frame lathe designs where the tool modules revolve around stationary protruding components.

The TRIMAX system uses recirculating ball bearing technology to render the system rigid both axially and radially, providing the strength needed for fast, safe form tooling on heavy wall pipe.  Per the manufacturer, "the vastly improved rigidity of the TRIMAX system also opens the doors to new... possibilities of special applications never before achieved with a split-ring machining system.  The capacity to accept much larger cutting loads and forces without adversely affecting performance maximizes the special accessory configuration extensibility of this machining system."  The system models and pipe size capacity are as follows:

TRIMAX Models Pipe Size Range
604TMX 2 to 4 inches
606TMX 2 to 6 inches
608TMX 4 to 8 inches
610TMX 6 to 10 inches
612TMX 6 to 12 inches
614TMX 8 to 14 inches
616TMX 10 to 16 inches
620TMX 14 to 20 inches
624TMX 18 to 24 inches


Risks Addressed:

Operating a conventional split frame lathe can create caught-in or -between hazards as worker hands, fingers, or other parts can be pinched or squeezed in between the rotating tool module and the external stationary components protruding out of the lathe. 

How Risks are Reduced:

The TRIMAX follows the Prevention through Design concept in which the tripper mechanism is housed inside the machining system.  As a result, the protruding components near the rotating lathe frame are engineered out thereby reducing caught-in or -between risks.  Figure 1 provides an illustration comparing a conventional split frame lathe design (top) with the patented TRIMAX design (bottom).

Figure 1. Split frame lathe designs with respect to pinch points. (Photo courtesy of Tri Tool)

There are currently no peer-reviewed studies with data showing the risk reduction when using this machine.  Anecdotal deduction, however, would suggest that having less stationary machine components near the rotating tool module will render less pinch points.

Additional Considerations:

It is recommended users follow all manufacturer guidelines before using this equipment to ensure worker safety and compliance with applicable local, state or federal regulations.

Besides reducing the caught-in or -between hazard, another safety feature of the TRIMAX is an “Auto Lock” system that locks the head stock in place whenever the frame is separated. This eliminates the need for the operators to manually install locking pins to keep the head stock from rolling out onto their foot or onto other personnel that may be working bellow.


Le, Jean Christophe, MPH - CPWR The Center for Construction Research and Training

This solution page was adapted from a direct correspondence with the inventor Joel Walton.


Tri Tool Inc.
To obtain information, visit TRIMAX Portable Machining System or contact 1-916-288-6100 customer.service@tritool.com

NIOSH Workplace Solutions Sheet
The National Institute of Safety and Health (NIOSH) has published a series of “Workplace Solutions”, which are easy-to-understand recommendations from NIOSH research results. Related to this Construction Solution, please find more information on: Supporting Prevention through Design (PtD) Using Business Value Concepts

Return on Investment

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