Polishing stainless steel tubes is a crucial step in the manufacturing process, as it creates a uniform and consistent surface finish. Stainless steel furniture, bull bars and bumpers for off-road cars are examples that often require tube mirror polishing, but while stainless steel is much more resistant to corrosion than ordinary carbon or alloy steels, in some circumstances, it can corrode.

AM Machinery Sales in Warminster, Pennsylvania, is distributing a new product—the MP100 polishing machinefrom Portuguese manufacturer NS Máquinas—that aims to solve the corrosion issue.

“Coastal line tube construction requires a smooth finish so that it gets harder for the corrosion to stick to the tubes,” president of AM Machinery, Tony McCue says. “A similar effect happens in process industries such as food and pharmaceutical.”

Many solutions for mirror polishing stainless steel tubes include centerless machines, which force the tube to spin while it passes through the polishing wheels. Although effective, McCue says this method restricts the types of tube that can be polished, such as long tubes, which tend to vibrate unless supported in bulky guiding tables and curved tubes, which cannot be turned around the polishing wheels due to their geometry.

The MP100 can mirror polish tubes because its wheels are turning around the tube, which is passing through the polishing station without any rotation. Makers of stainless steel curved tube products also commonly face the problem of applying the final mirror polishing in their bent tubes.

“This job typically uses manual machines, which end up being time consuming and labor intensive,” McCue says. “With the MP100, three planetary polishing wheels rotate around the tube, creating high pressure and delivering a high-gloss mirror polishing on straight or curved tubes.”

The operator only needs to transport through the polishing head while the cotton wheels do their job on the complete external diameter of the tube, he says, completing a consistent finish on the outer side as well as the inner side of the bend.

The MP100 features pressure control by foot pedal, enabling the operator to control the applied force during the tube polishing operation. In order to achieve a shiny surface, McCue says, the machine is equipped with an automatic solid polishing compound system.

“The operator can define the quantity of compound to be applied and simply start the process when it is required,” he says. “The MP100 has a working capacity on straight tubes up to 114 mm and was developed to polish different geometries for curved tubes.”

The MP100 also features an automatic feeding system, which transports straight tubes safely through the polishing units, enabling a consistent and high mirror polishing quality in a vibration-free process. McCue says the design of MP100 assures that—as opposed to centerless machines using a work rest—no tube support is located in the polishing area. As a result, he says, the NS Máquinas tube polishing machine assures no marks, no scratches and a perfect polished tube surface.