Thick Wall Stainless Steel Pipe
The capability of modern machines, mixed with the latest software and controls, reveals just how exact tube bending has become. True, materials variability and sure application-specific challenges make some level of unpredictability unavoidable.
Nevertheless, with the proper materials, tooling, lubrication, and machine, you could have a much better chance of reaching the proper bend—each time. Ram bending is one of the oldest, easiest, and least expensive kinds of tube bending. Your tooling also should take radial growth under consideration . If radial growth is extreme, the nature of the rotary draw process signifies that after the clamp die releases, the radius firstly of the bend might be noticeably totally different from the radius at the end of the bend.
Some ovality is suitable for sure functions, but unacceptable for precision work. That’s because as the outside stretches, the within radius compresses and at a sure level begins to wrinkle. Many name tube bending a black art, a mysterious course of with unavoidable trial and error. But in actuality, the basic ideas have remained the identical for many years. The know-how used to bend tubular workpieces has advanced considerably, however all of the mechanical magic can’t alter physics.
Some purposes, together with those with a larger coil pitch, require a further roll that guides the tube outward because the coil is being fashioned. Elongation happens throughout bending, and the surface radius stretches , which the fabric resists. This causes the surface floor of the bend to collapse, inflicting ovality, or a distortion of the cross section from its unique spherical shape.
The roller successfully “compresses” the tube against the central bend die. This technique is most common in symmetrical workpieces—these with identical bends on both aspect—often bent in one setup on a machine with two bending heads. This method works properly for tubes bent to a CLR that’s a minimum of 3 times the tube OD. If a workpiece has a one-diameter pitch and a big radius, the operator can lift the tube after one revolution to provide a steady coil.
To accommodate for radial progress, notably if it involves hard material and a three×D CLR or greater, you may want to use a bend die with a smaller radius. Compression bending makes use of a curler or compression die to bend the workpiece round a stationary bend die . The system clamps the workpiece just behind the rear tangent level.