The cold drawing process is a method of deformation of metal to obtain complex sections with great precision in one or more passes through a drawing die.
Produced in long lengths (6 to 10 meters), but often supplied cut to customer’s length requirements the use of cold drawn profiles can provide considerable savings when compared with other methods of manufacturing of mechanical parts, e.g. machining, fabrication or sintering.
Osborn Metals offers a wide variety of profiles in complex shapes:
- solid sections which are obtained by deformation of standard profiles or further refining of complex shapes derived from extrusion or hot rolling.
- “open” sections which are obtained by deformation of flat bars or sheet
- Hollow sections: complex shapes or circular forms with exterior or interior forms including splines
A part of Osborn Metals’ technical expertise lies in the choice of the pre-form and in the design of the drawing dies, it is this expertise which provides the finished product required by our clients.
By a simple cold deformation of the material the cold drawing process allows achievement of complex shapes, in one or more passes, with the dimensional tolerances equivalent to those which are normally obtained by machining.
The standard tolerances are generally +/-0.1mm or h11 but can be further tightened to achieve +/- 0.05 mm or even +/-0.02mm against specific customer needs.
These tolerances, which match those of the finished product, remove the need for machining operations on the section.
In addition, due to the nature of the process, the tolerances are guaranteed over the whole length of the profile without variance.
Cold drawing allows the production of sections which are technically or financially impractical with other methods of manufacture:
- original shapes allow customers to personalize their products without additional costs
- designs can include sharp corners and re-entrant angles
- complex sections in one piece replacing several assembled sections giving reduced costs and inventory
Material yield savings
The material yield saving is linked to the cold drawing process itself which works by deforming the material rather than machining it away.
The material yield saving come from two main sources:
- the ability to utilize a higher percentage of the raw material through the deformation process
- by avoiding repeated machining the final tolerances can be obtained directly through the process of cold drawing.
The savings produced by the cold drawing process are even higher when the base raw material has a higher intrinsic value.
Low tooling costs
The tooling charges for a set of drawing dies are very modest when compared to the set up costs for forging, casting and profiling.
Osborn Metals has in-house die making equipment which allows the company to be particularly flexible regarding modifications of the dies and also allows to be reactive in the producing of prototypes.
Quantities to suit the customer’s needs
The process of cold drawing is particularly economical when the volumes are high but stays competitive for quantities down to 500 kgs.
For repeat profiles Osborn Metals can hold the stock and provide exactly the quantities needed to a scheduled basis.