MAB has recently made important investments on R&D on new products; can you tell me something about it?
Yes, we have actually made important investments in the production of cold drawn steel bars from diameter 14 mm to diameter 32 mm. We wanted to give added value to the cold drawn round bars made on standard combined lines.
The innovation of this new production line is that we can draw bars with a length of 6 meters and cut them in half only after having controlled them with eddy current simultaneously with the following instruments:
Circograph to identify the so-called longitudinal defects to the bars (cracks, folds, etc.)
Defectomat to identify transversal defects (mainly of round-shaped scales)
Magnatest to guarantee the anti-mixing between different qualities and casts.
Thanks to these controls we are able to guarantee class 3 quality surface according to EN 10277 part 1, which is our minimum goal. We know that for some agreed products destined to particular utilizations this surface class is not enough, so we use very narrow control thresholds and more control instruments simultaneously.
The 6 meters long cold drawn bars are milled on both sides with a 30° angle for 3-5 mm, then controlled by eddy current and cut in half, no longer sheared as on the classic production lines.
Two bundles are then composed at a time, in which the two ends sawed in the centre will become respectively the two ends of the bars. According to the Customer’s choice, we leave those ends with a 90° angle or we chamfer them with a 45° angle with a depth to be agreed. Our warehouse standard is a 1/2 mm bevel on the sawn side and a 3 to 5 mm bevel on the other side (30° angle).
Once the bevel has been created, the 3 meters long bars are able to continue to form a bundle, while those with discontinuities that do not pass the quality controls are first marked and then taken by a manipulator that deposits them in a special waste basket.
Which are the advantages for the customers who choose these new high quality products?
Drawing bars with a length of 6 meters and cutting them by saw has enabled us to solve the following problems:
1° – The EN 10277 “Cold-finished steel products” does not provide the eddy current control on the ends of the bar. It is explicitly indicated that when an automatic eddy current control is used, a piece of 50mm at each end of the bar will be excluded.
We wanted the customer to use the bar in its entirety, without excluding the first 50 mm.
With this new method, we are able to control even the first centimeters of the bars (90° side) as the eddy current control takes place on the bar with a length of 6mt before being cut, excluding only
the end of it. Therefore, the customer can immediately use the initial part of the bar, without any waste, but putting just the end of it aside.
2° – The tip of the bar of 3 meters does no longer present the slight deformations typical of the shear cut. Customers’ goal is to have the less waste possible and with this new product line we are able to satisfy their need.
3° – If we would measure the ends of the bars made from classic productions, we could notice a dimensional difference of a few cents. This is a slight swelling near the ends, due to the lack of homogeneous support of the rollers during the straightening process, especially with high carbon content steel grades (44SMn28, 36SMnPb14, C45E). With the new product line we are able to remove this effect.
What inspired the idea of these new products? What were the difficulties you encountered and how did you manage them?
I would say that it was the market that pushed us to find alternative solutions to the classic standard productions and, above all, we listened to the needs of the increasingly demanding customers. Of course it was not easy to think, study, discuss, simulate and create a production line that would help us make a huge qualitative leap. However, with the precious contribution of all the managers involved, we achieved this goal.
Where this choice in the direction of technological and quality improvement head you? Is the market changing? How does MAB face this change?
From a qualitative point of view, Customers’ needs have grown a lot in recent years, in step with those of the final outlet markets (Automotive, Hydraulic, Earth Moving, Appliances, Furniture, etc.). To meet those needs it is necessary that we use the best available technologies in every step of the production process, from steel mills to drawing mills, up to the turning plants that use our products. MAB has always pointed in this direction and it is always looking for the best technological and control tools available on the market. It is convinced that one of the main reasons for its constant growth, not only in absolute terms but also in terms of market shares, is due to this strong commitment to quality.3
Where and how your customers can find out more about these products? Are there any other changes in the near future?
Our sales network is always updated on the technologies that we can make available to customers. Regarding the new production line, as it is a rather complex production process compared to traditional products, we invite our customers to visit our Company to experience all the advantages of this product. The market demands that we focus on the straightness of the bars and on their quality surface with no superficial discontinuities, so we are working to implement other production lines with increasingly innovative tools that can guarantee even better control.
Giovanni Pozzi – Quality Manager