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Today's Precision Stainless Machining Bars

In many cases, the raw material being used is a weak link in the screw machining process.

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You are only as strong as your weakest link. This old saying is becoming more and more evident in the precision screw machining industry as shops around the world continue to upgrade their machining operations with the latest advances in equipment and machining accessory technology. The new technologies now allow a shop to machine parts complete, with tighter tolerances and better finishes, at a lower cycle time with increased efficiency rates. However, if a part of the machining system is not up to par with the capabilities of the rest of the system, then everything must slow down to accommodate that limiting factor. In many cases, the raw material being used is the weakest link.

Even the top bar feeders available in the market today, with all of their technology to minimize vibration, cannot overcome the detrimental effects that standard cold drawn barstock can create. Indeed, an obvious way to overcome the problem is to improve the raw material. Today's raw material must have the straightness and overall precision to meet the machining systems' increasing demands. Furthermore, other critical raw material features such as improved machining grades, which are possible because of chemistry control as a result of newer melting technologies, can have their advantages negated if there is not parity between the physical and chemical qualities of the stock.

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In the early 1990s, the Ugine-Savoie mill in France recognized that the machining system had made key technological advancements. It still, however, remained hostage to the ability of the raw material. This prompted the company to move to market with a stainless bar product that had precision physical characteristics capable of keeping pace with the high machinability demands created from the advanced technology in the machining system.

Today, Ugine (Colmar, Pennsylvania) has developed a line of precision straightened stainless machining bars for high speed applications. The precision machining barstock is called SMQ, which stands for Screw Machine Quality. The need for the precision straight material became evident in the European market first because of its willingness to embrace the new high speed machining technology. This same high speed machining environment is now in the United States, and the conventional stainless barstock in the market has been causing vibrations and limiting productivity. The precision SMQ material has become a solution for overcoming these problems.

Application of engineered bar material provides consistent results developed by today’s shop owners. Depending upon the level of sophistication within a machining system, the improvements have meant the difference between making good parts or scrap, and they have increased the profitability of countless jobs through productivity improvements. The most significant results have come from the high-end Swiss-style CNC machines that have the most to gain from the benefits of this new stainless bar.

Finally, there is no getting around the topic of material handling when discussing bar straightness. Shops will never realize the benefits of a precision drawn bar if the integrity of the physical properties is not maintained in transit. For this reason, Ugine has taken great care to ensure that its material is delivered to the machine shops intact with the precision straight qualities that it left the mill with. This is done through the use of heavy duty boxing and mill packaging, and most importantly, making sure that the proper handling and care is taken when transporting and storing the material.

— Schmolz + Bickenbach USA