Important technical terms

Machinability
That means the property of a material, to be machinable by cutting under given circumstances. Each material has to be investigated with regard to its cutting behavior in various processing processes (drilling, turning, milling, etc.). Generally, there is good machinability, when:

• the machining force is low,
• the cutting edge stays sharp for a long time,
• a large machining volume is generated in a short time,
• the surface achieved is good and
• the chip shape is favorable.

Mandrel
A mandrel is an auxiliary device for the formation of cavities and is utilized in metal forming for indentation or forcing-through procedures. There is a differentiation between hollows and solid mandrels. For seamless tube production, mandrels are utilized for bar extrusion as well as for mandrel drawing as auxiliary devices, whereat the mandrel always determines the inner diameter of the deformed tube.

Mandrel drawing
In this procedure, the tube is drawn through the drawing die together with a mandrel, which determines the internal diameter. Because the tube firmly sticks to the mandrel after drawing, a detaching mill and a mandrel removal device are required.

Marking
Marking serves the identification of preliminary material as well as of the product within the manufacturing process, to be able to trace it back any time and to determine the production progress.

Martensite
Crystal type of iron (magnetic), which is characteried by a cubic body centered lattice structure. The acicular and very hard or brittle microstructure is formed, when austenite is quenched at comparably high cooling speeds, so that the carbon has no time for diffusion.

Material
A material is a matter with technically utilizable properties. There is a differentiation between various material groups, like e.g. iron and steel materials, non-ferrous metals, inorganic and finally organic materials.

Material test report
The Certified Material Test Report is a certificate required for materials according to ASME-Code Section III, which confirms, that the material complies with the specified requirements, including the results of all required analyses, examinations and investigations.

Measuring media
Measuring media are measuring devices, which are used for quantitative determination of the value of a physical quantity (e.g.: the measuring media thermocouple for the measurement of the temperature).

Melt
A melt is the liquid aggregate state of metals and alloys. The term "melt" is often used as a synonym for the determined chemical composition, i.e. for a preliminary material, which is produced in one cast.

Metallographic specimen
Is a flawless ground surface of a representative even area of the material to be examined, on which the real microstructure can be recognized. Therefore, no changes of the sample must occur during preparation. Except for exemptions, the preparation of a metallographic specimen comprises of the following working steps, which, according to the method applied, mostly can still be multiply subdivided: sampling, bordering, marking, grinding, polishing, cleaning and etching.

Microstructure
Is a joint of grains (crystallites) and must not be confused with the constitution structure (lattice structure - unit cell). There are two terms for the identification of the microstructure of a pure metal: grain size and grain shape. Pure metals have a homogeneous microstructure, because all crystallites have the same structure. The grains are completely equivalent to one another with regard to their lattice structure and the type of atoms.

Minimum wall
The term "minimum wall" means the wall thickness of a seamless stainless steel tube, which in no case must be undercut.

Mix up test (PMI - Positive Material Identification)
By creation of an electrical arc, the surface of the specimen is partly vaporized. Each element has a specific spectrum. Due to this spectrum, conclusions can be drawn to the material (chemical composition). Alloying components (chromium, molybdenum, titanium, manganese, etc.) can be qualitatively determined with this method in just a few seconds.

Monitoring
Monitoring is a snapshot of the quality level in the production area, which is executed according to a checklist in a two-week interval.

Monitors
Are employees from all sectors of production, appointed by the quality manager, which perform the monitoring.

MOVEX
Designation of a computer system for the efficient administration of the various resources of a company (employees, machines, funds, ...) and enables the integration of several company units with different languages, currencies as well as legal bases.

Multiple lengths
In case a customer orders tubes in multiple lengths of a certain length, the delivered tubes may be delivered e.g.: in the double, triple, ..., x-fold length (within a certain length range). The required cutting allowance is to be agreed with the customer in any case.