Tube & Pipe
Custom machine tools provide effective fabrication solutions
A comparison of a standard tube squaring machine on the left, with a customized version offering rapid cam clamping and the ability to cut variable angled ends.

ver the years, a wide range of portable equipment has been developed to perform metal cutting in-place, where it was not feasible to take the workpiece to a floor-mounted machine. For example, magnetic-based drills can accomplish drill-press accurate holes anywhere they can be attached. Similarly, portable powered threading machines quickly and easily generate excellent pipe threaded ends in the field without the need for a machine shop.

For work on tube and pipe, portable machine tools that were primarily designed for simple end preparation for welders, are being custom repurposed as dynamic and practical fabrication solutions that offer many significant advantages over conventional machine shop equipment.

Along with obvious advantages—reduced size and expense—portable machine tools are industry-proven for producing high-quality fabricated parts. They are especially effective when the production requirements for parts are of infrequent or unexpected demand, making the setup of large, dedicated shop equipment impractical or cost prohibitive.

Portable machine tools are industry-proven for producing high-quality fabricated parts.
Portable cold-cutting, beveling, severing and end-preparation machinery became increasingly practical as tube and pipe welding procedures became more advanced. Portable equipment is available to cut all sizes and schedules of tube and pipe, with options of AC electric, cordless DC, pneumatic or hydraulic power, and such equipment can reliably cut virtually any material from carbon steel, aluminum, brass or stainless, to more specialized materials such as Inconel or titanium.

Beveling tools typically mount to an ID bore with an expanding mandrel and produce simple or complex beveled ends, providing material clearance for the welding arc to reach the root of a weld joint profile. Beyond their basic intent, beveling tools have been custom modified to perform a wide spectrum of tasks such as high-volume grooving for non-welded pipe fittings, deep counterboring for Nondestructive Testing (NDT), and coating removal systems for working with corrosion-resistant pipe.

Severing and squaring portable machines are of particular interest to companies looking for a practical approach to tubular part fabrication without the expense and difficulty of converting large conventional shop machinery to a dedicated production role. This class of machinery was designed for precision cutting for construction and maintenance on piping systems for food and beverage plants, and hydrocarbon, semi-conductor and pharmaceutical production roles.

Due to the portable machine tool’s compact size, power options and the ability to bench mount or hand hold it, manufacturers have custom modified such equipment for an infinite range of applications and fabrication purposes. Cutting method options include form tool bits, standard carbide tool holders and roller cutting wheels that sever tubes without the particulate debris of saws or grinding.

Other customizable options involve methods of clamping raw stock, custom fixturing to grip the ID or OD surfaces of workpieces, and special tool bits for non-typical or complex end geometries.

An automatic roller-wheel type cutting machine was customized to open hazardous metal canisters without sparks or debris. The console offers full remote control of the machine.
This tube severing machine is configured for auto bit feed, auto bit reset, and has been fitted with custom safety guards.
Tubular parts of extremely accurate lengths can be easily produced with burr-free ends and absolutely square to the bore centerline. Custom mounting accessories permit the secure holding and cutting of challenging part shapes that would be impossible to process on conventional machinery.
One of the challenges of tubular part fabrication is the precision cutting of thin wall thickness stock. Sometimes, parts can actually become distorted when being cut from too much clamping force concentrated at too few points, affecting the desired shape and uniformity of the finished part. Distortion is a critical issue when parts will be welded by robotic systems that demand the highest degree of consistent accuracy for minimal welding defects.

The aerospace industry depends on high-integrity welded thin-wall alloy and stainless tubing assemblies. Many cutting situations require “full support” clamping elements that provide radius matched surface engagement with either the bore or outside diameter of the component being cut.

Distortion-free clamping can be accomplished by full support collets, saddle sets or contoured support pads depending on the type of machine used.

Accurate angles
Shops are sometimes required to generate cuts on a specific angular bias as opposed to a perpendicular cut. Welded tubing system elements require angled ends so that when they are welded, the finished assembly is contoured or circular in nature (i.e., aerospace exhaust systems). This can be a tremendously challenging procedure to perform on conventional machinery but one quite easily achieved with reliable, repeatable accuracy on custom modified portable machine tools, especially in high-volume production roles.

Portable machine tools used in dedicated production are very compact and flexible compared to large floor-mounted shop equipment. Fabricators gain the flexibility to set up semi-permanent workflow layouts responsive to fluctuating production demands and part inventory requirements. Machinery can be easily set up, run and then easily stored, moved or reconfigured to produce different components, in less time and in less space.

In many instances, the cutting operations achievable by custom machinery can be virtually impossible to perform with any other machinery.

ID mount beveling machine and a Custom OD mount severing machine
This ID mount beveling machine, left, was modified to add a bench-top mounting base, faster tool bit feed, and internal mounting supports for working with thin-wall pipe. A custom OD mount severing machine, right, was configured to cut large, thin-wall tubing. It features support pads that spread clamping forces without causing distortion.
Working with a portable machine tool OEM that offers custom engineered equipment, accessories, tooling and mounting fixtures can be surprisingly fast and easy. In many instances (such as when trying to perform an oblique sever to precise angles), the necessary operation can be accomplished with a standard tool combined with a rotary stage to offer a range of cutting adjustment.

In other circumstances, if an existing machine cannot be modified to perform the specific operation required, custom machinery can be designed and manufactured from the ground up, and still be cost effective if the needed fabrication can not be efficiently and/or precisely done by other means.

Materials remain an important consideration when contemplating whether a custom machine tool is a worthwhile addition to your shop. Since portable machine tools concentrate their torque on the travel of the bit edge against the tube or pipe end, they can provide impressive amounts of power with precise incremental feed control.

When using machines that rely on purpose-designed tool bits for cutting, the resultant cut geometry is a direct function of the tool bit characteristics. That’s why companies over time develop countless tool bits for specific materials, wall thicknesses, end prep profiles, as well as combination bit sets that can perform simultaneous end beveling, squaring and counterboring.

A portable machine tool manufacturer can have bit designs that number in the tens of thousands, each produced to obtain specific cutting results on a specific material. While that sounds like a daunting number, equipment manufacturers can assist fabricators with specifying exactly the right tooling to perform their required operation rapidly and reliably.

Along with custom modifications for cutting functions, portable machinery can be further enhanced with tabletop base mounting, safety guards, and either pendant or fully remote control interfaces for reliable operation in hazardous or confined spaces.

Some fabricators choose to make custom modifications that directly affect the cycle rate or the operator’s ease of use. This can include practical combinations of automated material feed, part indexing, micrometer feed mechanisms for exacting cut depth control, automated clamping and unclamping features, automated tool bit feed control to ensure repeatable precision, part ejection, and automatic resetting of the tool bit after a cut has been completed, to be ready to perform the next cut sequence.

Suffice to say, the possible fabrication options of portable machine tools are virtually limitless. Introducing a custom-modified machine tool that has been specifically built to rapidly and dependably fulfill a challenging part production requirement, can have a significant positive impact on production workflow, and save time and money.

Tri Tool Inc.,
Rancho Cordova, California, 916/288-6100,