PM Blog

Stainless steels are one of the more difficult materials to machine. The addition of sulfur to ease machinability, as in austenitic grades such as 303, are still prone to built up edge, difficulties in maintaining a good part surface finish and reduced tool life. Reducing this sulfur addition as needed in 304 and 316, make these matters even worse and adds reduced chipping tendency to the list. Alchemists have searched high and low to find the recipe that turns lead into gold. Steel producers searched for a formula for stainless steels that would make these materials friendlier to machinists.

Back in the early to mid 20th century, metallurgical scientists discovered the usefulness of sulfur in stainless steels. They found that sulfur forms compounds in the stainless steels that will help break the stainless steel chip during machining and form a lubrication layer on the top of the cutting tool, reducing friction and extending tool life. The use of sulfur expanded throughout the stainless industry to give rise to free machining grades such as 303, 416 and 420F.

Shops deal with different types of material, each with their own challenges. One material that can present some difficulties is 4140 steel. This material can have a tough crust or scale on the outside that is tough to machine and can wear down cutting tools quickly. However, special cutting tools can ease this process. For a shop in Mississippi, switching to a more efficient and economical tool from Tungaloy increased the number of parts it can produce per insert, saving time and money.

The rotary broaching process applies a specially designed tool to the workpiece to cut non-round shapes that include splines, keyways and polygons. The process works because the head of the broaching holder is offset from the centerline of the shank on a 1-degree angle. This orientation creates a shearing effect around the edges of the form being cut—essentially only a section of the form is being cut at any given time—which greatly reduces the amount of cutting pressure needed to form the desired feature.

The rotary broach holder has a spindle that rotates independently of the rest of the holder. Thus, when rotary broaching on a lathe or screw machine, when the stationary broach tool meets the rotating part, it begins spinning at the same rate as the part.

It is mandatory for precision machining shops to ensure reliable processes across its entire range of applications and materials. This can only be achieved by using reliable tool systems, having a team that’s experienced in custom developments and having a well-conceived ERP system that ensures rapid and smooth workflows. Zahn GmbH (Aglasterhausen, Germany) found the perfect partner to ensure all these needs in Arno-Werkzeuge.

Over the years, Zahn GmbH has gradually specialized in the production of complex, high precision turned and milled parts for major customers in the automotive and aerospace industries. Whether it is a prototype or a series production part, the company constantly works to tight tolerances of 4 microns as well as short-term delivery dates. “We are well positioned to cover a range of materials and applications, and we can react flexibly to customer requirements,” explains Managing Director Lars Pramme.

In today’s economy, businesses have two main audiences their leadership teams need to connect with—internal customers (employees) and external customers (the people who buy their goods and services).

Often times, companies use facts and figures to connect with these audiences. These pieces of communication only appeal to the logical brain. Rather, businesses need to start telling better stories—heartfelt and inspiring stories that connect with people, because storytelling is the new business currency.