The tube and pipe fabrication technology area covers sawing (band, circular, and friction) and other cutting processes, such as abrasive, flame, laser, oxyfuel, plasma, and waterjet. It also discusses forming processes, including bending and end forming. Finally, it includes a handful of miscellaneous processes, such as trimming, beveling, finning, grooving, threading, and spinning.
December 2, 2008
Many seamless tube producers in North America use cross-roll piercing mills built in the 1950s that were based on designs from the1930s. While it would be advantageous to replace such aged equipment, that isn't always necessary. A minor equipment upgrade can do wonders. Improving the bar steadiers—the devices that hold the mandrel the steady as the pipe exits the mill—can greatly improve the mill's output and reduce the pipe's wall thickness variation.
November 25, 2008
For many bending applications, it is common practice to determine the necessary length of tube, run a few samples, make some minor adjustments, and then start production runs. The problem is that the initial evaluation may have been based on safe, by-the-book estimates and calculations. Re-evaluating a bending project might yield substantial material savings.
November 25, 2008
Bending serpentine profiles—successive 180-degree bends, which typically are used in refrigeration systems—can be a challenge. By their nature, they tend to cause interference among the various bend dies, and they can be difficult to handle. Good planning in selecting a bender, planning the process, and paying close attention to infeed and outfeed options, can help make a serpentine project successful.
September 30, 2008
The best material for a tube bending tool is the most cost-effective in terms of the ratio of tool life to tool cost. A cost-effective tool tends to wear out rather than break at the end of its service life. This article addresses choosing the optimal material for a rotary die tube bending machine's full toolkit.
September 16, 2008
Sculptor and fabricator Brett Richards of BR Sculpture, Chicago, got a contract to make a frame for an oval mirror—a length of square tubing bent to a perfect ellipse. Not knowing too much about the vagaries of bending tube, he figured he'd spend a few thousand dollars on a simple bender. After searching for months, he happened to see an elliptical shape made from square tubing in a vendor's booth at FABTECH.
August 26, 2008
Motorcycle popularity has grown substantially in recent years, and many small shops that produce custom-made and limited-production motorcycles have sprung up. Two such shop owners, Brad Ruel of The Wrench and Mark Evans of Diablo Chop Shop, took it one step further and joined forces to combine their experience in designing and manufacturing semifinished (kit) motorcycles, completed bikes, and a substantial line of aftermarket parts.
August 12, 2008
Pointing, sometimes called tagging or swaging, is a process that reduces a tube's end to permit it to pass through a draw die for a drawing operation. After the tube end goes through the draw die, gripper jaws converge on the point to begin the draw operation. Push pointing is accomplished by gripping a tube and advancing pointing dies over the end, resulting in a reduced end diameter.
July 15, 2008
Conventional tube bending data, regardless of format, is entered manually and therefore susceptible to errors. A modern approach involves using a CAD system to generate a STEP file, which the CAD program exports directly to the bending machine. This method is fast and eliminates errors. The drawback is that such a system requires additional database management efforts.
July 15, 2008
Verifying that tube was bent correctly is not as simple as it sounds. Bending specifications and tolerances aren't cut-and-dried, but are open to interpretation. The fabricator, the end user, and the check fixture designer might have three different perspectives on specifications and tolerances. Achieving a consensus is critical for designing and manufacturing a check fixture.
May 13, 2008
Fabricators have two broad choices in the bend tooling they select: standard or custom. Using standardized tooling provides cost-effective versatility. A well developed tooling inventory can accommodate nearly any bending job. On the other hand, custom tooling is designed for speed and efficiency. Customized tools make one part and one part only as fast as possible. The trade-offs boil down to time and money: standardized tooling requires more time to set up but costs less. With custom tooling, changeover is quick, but the tooling costs more.
April 15, 2008
In celebration of its 50th anniversary in April 2005, McDonald's® opened a 24,000-sq.-ft. restaurant in Chicago. The restaurant's most eye-catching feature is a pair of parabolic arches that stand 60 ft. high. Constructed from 20-in. by 12-in. tubes, the arches were curved by Chicago Metal Rolled Products, an OEM component subcontractor. Operating within a tight time frame, CMRP helped the structural steel fabricator and erector, Tefft Bridge & Iron LLC, by bending the tubes in multiple locations on longer sections to reduce the number of weld splices needed.