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Machining: We let the chips fly

Come with us on a little journey through time to the East African plateau of today's Kenya, three million years before the birth of Christ.  Because there a being which just lets himself down on the ground, holding two stones in his hands, that only remotely reminds us of a person.  It begins to hit the stones together. It cuts off sliver after sliver until an edge is formed.  Sharp enough to penetrate even thick animal skin or to cut sturdy plant fibers.

These primitive tools from our distant ancestors are the oldest evidence of a cultural technique that has been used throughout human history: machining.  Without machining, the Egyptians would not have built pyramids and the Europeans of the Middle Ages would not have built cathedrals.  The industrial revolution would never have happened and you couldn't travel by train or car - because nowadays machining is more important than ever.

In this article you will learn what is meant by machining these days and what Walzwerke Einsal has to do with it.

Machining: What does that mean?

In principle, machining is one of the manufacturing processes, more precisely a cutting process - well defined in DIN 8580 - and is therefore a technique for manufacturing geometrically determined workpieces.

Machining encompasses all processes in which the shaping takes place by separating chips using a tool.  When you drill a hole in a board, you are machining because the drilling dust consists of tiny chips.  The prehistoric man from above used the techniques of chiselling and scraping to separate splinters - i.e. chips - from his flint.

Machining can be found almost everywhere in material processing and allows numerous types of forming.  In addition to the drilling already mentioned, the most common machining processes include turning, milling and grinding.  But planing, sawing, rubbing, filing or rasping are also machining processes.

So the next time you rub parmesan over your spaghetti, you may not be a machinist, but you are actually using a machining technique.  But what does that have to do with Einsal?  After all, we are a rolling mill and not a machining plant...

Keyword: Machinability

The answer, of course, has to do with the fact that steel is the most commonly machined material in the 21st century.  As is well known, our material is not only extremely resilient, resistant and therefore universally applicable - it can also be excellently machined.  However, only if it has been appropriately alloyed beforehand and its microstructure has been optimized by cold forming.

On the one hand, the machinability of steel depends heavily on its internal crystalline structure and the cooling lubricant used during the forming process.  On the other hand, it depends on its chemical composition, because certain alloyed elements have a lasting effect on the machining properties of a material.

The best-known representatives of easily machinable steels are free-machining  steels with grades such as N1.4305, 1.4104 and 1.4005 according to DIN EN 10088-3 or AISI 303, 430F and 416 according to ASTM A582. Three alloy elements are particularly important in their production.

  • Lead: Lead is often added to low-alloy free-machining steels. The metal melts even at low temperatures and thus forms a protective lubricating film between the tool and the chips.  This reduces the frictional forces that occur and thus tool wear.  It also contributes to good chip breaking.
  • Sulfur: The element sulfur forms manganese sulfides in the material and thus increases the melting point.  This in turn leads to chips that break faster and thus to a better surface quality of the workpiece.
  • Phosphorus: In low concentrations, phosphorus ensures that chips break more easily and thus a higher surface quality. However, phosphorus is only reluctantly added to the alloy because it embrittles the material.

However, not only phosphorus worsens the material properties.  Lead and sulfur are also mostly undesirable in steels because they reduce its strength and corrosion resistance.  The choice between a steel that is as durable as possible and its machinability is therefore always a compromise and is largely determined by the intended use.

We manufacture near-net-size dimensions, which means that you have less redundancy.

Why rely on good machinability at all?

At this point you are  probably asking yourself why you should value the machinability of steel at all.  Why not just take the sturdiest one and drill, mill or grind a little longer?

The simple answer is: Because it's just not practical.  After all, poorly machinable steel leads to extremely high wear on the tools, reduces their service life and increases maintenance costs - so it costs you a lot of time and money.  In addition, the results are more than unsatisfactory, because poorly machinable steel produces a poor surface quality.

In comparison, steel that is easy to machine...

  • reduces the cutting forces: If only little force is required for the cutting process, your tools will last longer and have to be replaced less often.
  • produces optimal chips: Chips that are too coarse can hinder the production process because workpieces often have to be reworked.  Good machinability avoids this problem.
  • ensures a long service life: where machines have to be serviced less often, they can work longer - and longer service lives mean more economical work.
  • forms smooth surfaces: the surface quality of easily machinable steel is significantly better after forming and thus ensures higher quality end products.

The advantages of easily machinable steel cannot be denied.  In the end, as already mentioned, it is primarily the intended use that decides on your optimal material.  But how do you find out which steel is right for you? 

Your advantages with Walzwerke Einsal

The most reliable way to find the right material is to rely on a German manufacturer with the necessary know-how.  For example us, because we...

  • advise you comprehensively: Our experts know exactly which steel you need for your project and are happy to answer your questions.  Regardless of whether you contact us by phone, email or our chat function.
  • deliver close to final dimensions: We manufacture continuously and in dimensions close to the finished product - for example in the dimensions 66 x 61 or 74 x 22 millimeters.  For you  this means less waste material, less tool wear and therefore lower costs.  And it's good for the environment, too.
  • manufacture according to your specifications: We take your wishes into account and manufacture right-angled geometries with special tolerances or special mechanical properties.  In this way you get exactly the steel that meets your requirements.
  • enable special profiles: Do you have a drawing of your desired profile?  We can also take that into account.  This will further reduce your processing times or even eliminate them entirely.
  • offer the shortest delivery times: Don't wait forever for your container from overseas.  Who knows when the next ship will be stuck in the Suez Canal.  We have machining-optimized primary material in stock in all common grades such as 1.4301, 1.4307, 1.4401, 1.4404 or 1.4305.  In addition, we can also order other grades from our European partners at short notice.
  • also deliver very small quantities: not every project requires tons of steel.  We accept your order from very small quantities of 500 kilograms.

So whether you want to drill, mill, turn or grind - we will be happy to advise you and find the ideal material for you.

We are looking forward to your contact.