Features of parts being produced through rotary rotary swaging
Depending on the amount of reduction in the cross-section of the blank, and on the hardness of the raw material, we can get a corresponding increase of the tensile strength of semi-worked part. This advantage of cold-forming allow to use materials with a reduced strength, having therefore a supplementary saving on costs. At the same time, admissible loads on parts can be also higher.
As a further benefit, internal tensions generated by the compression of fibres on parts surface, may increase their strength to alternate deflection.
Our experience also showed that reduction of the cross-section we can get from each swaging step are higher than the ones we can get from cold-drawing, or push-forming.
It was also proved as sections being rotary swaged can generally be further cold-formed through other systems, without having to be annealed before, thanks to a remaining elongation capacity.
As much as the cross-section of material is reduced, as much the corresponding quality of the surface improves. Opposite to the surfaces produced through chips-removal, parts produced with rotary swaging have a very low roughness, and a better resistance to friction.
Possibility of use
Rotary swaging applied to solid bars, tubes and wires, beside other raw materials, such as extrusions and profiles allows to reduce their cross-sections, to change their profile, reduce-down and straighten without chip-removal. Parts can be either swaged just on a portion of their length, or all along their complete layout without interruptions. In some cases, two parts can be mechanically locked one inside the other, after having matched the two parts together. Metal wires can be downsized, while profiles and tubes can be profiled inside, or outside.
n most cases, are cylindrical blanks to be cold-formed in a rotary-symmetrical section. However, it's also possible to swage down some profiles starting from sections which are not cylindrical.
For instance, it's possible to produce square- or hexagonal-sections, etc., out from cylindrical blanks.
Tubes and hollow parts may be swaged down on internal mandrel,
therefore sized inside and prepared with a inner profile (splines, square- or hexagonal-hole, etc.). Tolerances we can get from rotary swaging are comparable to the ones available from modern chip-removal machine tools. These tolerances depend on the forming degree, on quality of dies and on parts diameters, ranging from +/- 0.02 mm. and +/- 0.2 mm. in the average.
Almost any material may be processed through rotary rotary swaging, provided they have enough elongation capacity. Oftentimes, is also possible to operate hard-carbides at low cost.
Semi-worked tungsten materials, and high-tensile nickel-alloys allow to be rotary swaged and - in some cases, whenever necessary - these blanks can be introduced as pre-heated into the machine.
Based on a.m. technical advantages, rotary swaging offers many application possibilities in different industrial sectors, such as:
- Automotive components
- Aeronautic and aerospace
- Agricultural machines
- Electro-technique
- Measurement and adjustment systems
- Warehouse and gardening tools
- Medical implant equipment
- Rotary mechanics
- Optical industry
- Tooling construction
- Welding and brazing devices
- Office furniture
- Metal-joints and fasteners
- Writing instruments
- Jewels and luxury articles
WORLD'S FIRST HIGHSTRENGTH STEEL MATCHED SPECIFICALLY TO ROLL FORMING
SSAB Swedish Steel has developed Docol Roll – the world's first advanced high strength steel made specifically to roll forming. This steel is available in two strength grades and can be formed to very tight radii.
The new Docol Roll cold-rolled, high strength roll forming steel is characterized by high yield strength, good dimensional stability after roll forming, and suitability for being formed to tight radii. The steel is produced in two strength grades – Docol Roll 800 with a minimum tensile strength of 800 N/mm2 and Docol Roll 1000 with a minimum tensile strength of 1000 N/mm2.
In addition to high tensile strength, Docol Roll also has a high yield strength, and the difference between the yield strength and tensile strength is small. This is the reason for the good roll forming properties of the steel. As a result, the profiles produced are dimensionally stable and flat, with low stress differences in the cross-section.
"Docol Roll minimizes the risk of bending or twisting of the profile, explains Karl-Inge Nilsson, Product Manager for Docol. "Another benefit is that the material can be formed to very tight radii that used to be impossible to reach with steels of this strength class. This is possible thanks to its high purity which, in combination with a new annealing process, allows roll forming of parts with very tight radii."
Docol Roll is the first advanced high strength, cold-rolled steel on the market designed specifically to roll forming. Even at the first development stages, the new steel aroused great interest in the automotive and other industries, and the product has been tested and evaluated in real-scale trials.
"This is a brand new steel for a market in which the interest in roll forming is steadily growing," says Karl-Inge Nilsson, "and where we anticipate a major breakthrough for Docol Roll in the future."
The keen interest of the automotive industry in roll forming is due to its high productivity at low production costs that the method offers. The bodywork and the safety parts will certainly be the first items to be made in Docol Roll.
This method has been previously used for producing sheet steel parts for the building industry, although the benefits of roll forming are also evident in other industries, particularly in combination with high strength steels.
"Several furniture manufacturers use roll forming in their production, and their use of high strength steels is also increasing," says Karl-Inge Nilsson. "Furniture contains a number of parts that are suitable for roll forming, and the trend here goes towards thinner profiles that can nevertheless withstand high stresses; this makes high strength steel an interesting proposition. In this sector too, we can therefore see a good market for Docol Roll."
Docol Roll is now being launched throughout the world and will be available at SSAB Swedish Steel sales subsidiaries and also through distributors.
SUPPLIES FOR DIFFERENT SECTORS
Multi Bending Labor, a company in Casaleone (VR), is specialized in bending metallic pipes with numeric controlled machines of the last generation. In addition to bending, this company can also perform other duties such as pricking, threading, soldering, outlining, and printing (Picture 3) on pipes whether they are in carbon steel, stainless steel or aluminum.
The company is involved with several product sectors with very different demands, because pipes are employed in the production of many different products. With time, Multi Bending has increased its fleet of machines suitable to the production of any geometry and shape that can be obtained from pipes.
At first Multi Bending was into agriculture and earth movement machines; protections, roll bars, bull bars etc. are still produced. Then it started to provide supplies to clean-up companies by making accessories for cleaning machines, vacuum cleaners, electrical brooms etc.
The company can take care of any order with enthusiasm, even the complex ones, placed by different customers. Business with the oenological sector (Picture 1) started with the supply of props for placing and storing the barrels in the cellars.
That is when a new machinery started to be employed: it can bend pipes with non fixed computer programmed radius.
This capability, seen with great interest by customers, made it possible for Multi Bending to produce also the first few items for fitness industry, such as components for gym machines, spin bikes, aqua bikes.
Multi Bending started to produce pieces of furniture such as chairs, armchairs, coffee tables and accessories for apparel stores (Picture 2).
The company had also a relationship with the INFN (the national institute for nuclear physics), and projected aluminum arches used in the particles accelerator built in Switzerland.
Other products include piping for railways braking system, props for the chairs used in the subway wagons, components for swimming pools (including those which will be used for the Olympic Games of 2008), structures for bikes, serpentines for bread ovens and for glass treatment plants, stove and kitchen handlers, airport chairs, hospital and medical equipment, gardening components, hobby tools, structures for scales etc.
Multi Bending production is historically connected with the production of optional components used to equip commercial and industrial vehicles, as well as accessories such as small ladders or bike props. Lately, a sector for the production of automobile components was added to the plant, which is still expanding (Picture 5).
It is not easy to satisfy so many different customers who have different needs, but nevertheless a proper organization and attention to the details established us as a landmark for the customers, and allows us to be always ready to satisfy new increasingly challenging demands.
Our company can not only produce the requested items, but can also support the customer throughout the planning phase and help him to figure out which are the best solutions both under the practical and the economic point of view.
The commercial sector, with the experience acquired throughout the years, can figure out which are most suitable materials to meet the demand of the customer; the technical sector analyzes the demands and the needs of the customer and satisfy the order that is the checked for quality and conformity with tri-dimensional software tools.
Thanks to the experience we have acquired, we can plan and make internally the machines and tools that are needed to complete the production; a list of standard tools that have already been made is given to the customer for him to choose the most suitable for his order.
Our goal for the future is to extend our production range so that we can provide a product that is more and more complete.
Our mission is to help the customer with any means to establish a long and solid cooperation with him.
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