Metal tubing plays a ubiquitous role in the contemporary world, used in everything from automobile engines, to air conditioners, to industrial machinery. Tubes come in a staggering array of shapes, sizes, and metals. Regardless of the specific diameter or composition of a tube, however, one thing tends to hold true: most tubes must be bent into a specific shape in order to serve their intended purpose.

Tube bending is an art form that can take years to master. Not only must the shape of the tube closely conform to the design specifications, but it must be bent in a way that does not reduce its structural integrity. If you would like to learn more about how manufacturers bend tubes, read on. This article will introduce you to three of the most commonly used techniques.

1. Ram Bending

Ram bending represents the oldest and most basic form of tube bending. For an example of a ram bent tube, look no farther than the exhaust pipe on the bottom of a bar. True to its name, ram bending involves creating an angle in the metal tube by applying acute pressure to one or more points - in other words, ramming the metal in a highly controlled manner.

In this regard, ram bending can be seen as a cousin to die and punch bending, a technique used in bending solid metal plates. The ram in question operates by means of a hydraulic press, which forces it against the tube. The tube itself must be clamped down at one end, to prevent it from shifting during the bending process.

Ram bending requires a lot of skill on the part of the operator. For one thing, it be difficult to line up the bend site correctly. Ram bending also presents another challenge in that the internal diameter of the pipe is not supported in any way. Excessive pressure may thus lead to an unacceptable degree of stretching on the outer wall, and crumpling on the inner wall.

2. Roll Bending

Roll bending offers excellent results when dealing with large diameter sections of tubing. This style of bending tends to be utilized most for heavy-duty industrial applications. It excels at producing bends with very precise radii. In general, roll bending tends to do best as a method of creating gentle curves, as opposed to sharper ones.

A roll bending machine consists of three rollers, usually arranged in a triangle orientation with respect to one another. Manual or hydraulic forces the tube through these rollers, which remain in a fixed position. As the tube passes through, it takes on the curve implied by the positional relation of the rollers.

3. Rotary Draw Bending

Where sharp, precise bends are desired, no bending technique offers betters results than rotary draw bending. This technique makes use of dies, which impart the desired curve to the tube. The so-called counter die - also sometimes referred to as the bend die - contains a void space which corresponds exactly to the diameter of the tube, as well as to the desired bend angle.

The pressure die acts to force the tube into the counter die, gradually applying pressure until it has seated itself fully in the mold. This fixed system of dies gives rotary draw bending excellent repeatability. In other words, each section of tube formed in a rotary draw machine will exhibit exactly the dimensions. This reduces the chances of mis-forming or over-bending that can plague other methods of tube bending.

Tube bending represents one of the most vital - and technically diverse - of all metal working skills. To learn more about how professionals bend tubes to achieve the desired results, contact the pros at KIMS International.