Support & FAQ

metal working

Posted on 04. Dec, 2015 by admin

>This section provide technical terms related to metal fabrication process and answer to most frequent questions ...

Laser cutting - for metals has the advantages over plasma cutting of being more precise and using less energy when cutting sheet metal, however, most industrial lasers cannot cut through the greater metal thickness that plasma can. Newer lasers machines operating at higher power (6000 watts, as contrasted with early laser cutting machines' 1500 watt ratings) are approaching plasma machines in their ability to cut through thick materials, but the capital cost of such machines is much higher than that of plasma cutting machines capable of cutting thick materials like steel plate. The main disadvantage of laser cutting is the high power consumption. Industrial laser efficiency may range from 5% to 15%. The power consumption and efficiency of any particular laser will vary depending on output power and operating parameters. This will depend on type of laser and how well the laser is matched to the work at hand. The amount of laser cutting power required, known as heat input, for a particular job depends on the material type, thickness, process (reactive/inert) used, and desired cutting rate.


Metal fabrication - is the building of metal structures by cutting, bending, and assembling processes:

* Cutting - is done by sawing, shearing, or chiseling (all with manual and powered variants); torching with hand-held torches (such as oxy-fuel torches or plasma torches); and via numerical control (CNC) cutters (using a laser, mill bits, torch, or water jet).

* Bending -is done by hammering (manual or powered) or via press brakes and similar tools. Modern metal fabricators utilize press brakes to either coin or air-bend metal sheet into form. CNC-controlled backgauges utilized hard stops to position cut parts in order to place bend lines in the correct position. Off-line programing software now makes programing the CNC-controlled press brakes seamless and very efficient.

* Assembling - (joining of the pieces) is done by welding, binding with adhesives, riveting, threaded fasteners, or even yet more bending in the form of a crimped seam. Structural steel and sheet metal are the usual starting materials for fabrication, along with the welding wire, flux, and fasteners that will join the cut pieces. As with other manufacturing processes, both human labor and automation are commonly used. The product resulting from fabrication may be called a fabrication. Shops that specialize in this type of metal work are called fab shops. The end products of other common types of metalworking, such as machining, metal stamping, forging, and casting, may be similar in shape and function, but those processes are not classified as fabrication.

* Welding - is the main focus of steel fabrication. The formed and machined parts will be assembled and tack welded into place then re-checked for accuracy. A fixture may be used to locate parts for welding if multiple weldments have been ordered. The welder then completes welding per the engineering drawings, if welding is detailed, or per his own judgment if no welding details are provided. Special precautions may be needed to prevent warping of the weldment due to heat. These may include re-designing the weldment to use less weld, welding in a staggered fashion, using a stout fixture, covering the weldment in sand during cooling, and straightening operations after welding. Straightening of warped steel weldments is done with an Oxy-acetylene torch and is somewhat of an art. Heat is selectively applied to the steel in a slow, linear sweep. The steel will have a net contraction, upon cooling, in the direction of the sweep. A highly skilled welder can remove significant warpage using this technique. Steel weldments are occasionally annealed in a low temperature oven to relieve residual stresses. Such weldments, particularly those employed for engine blocks, may be line-bored after heat treatment.

Question One
Posted on 04. Dec, 2015 by admin

Q:

A:

Question Two
Posted on 04. Dec, 2015 by admin

Q:

A:

Question Three
Posted on 04. Dec, 2015 by admin

Q:

A:


Link to us => *** Links ***