Technical Glossary Aluminium Profiles

ALnarchy® Brand

Symbolic own brand from mejo against the power and greed of large corporations. Stands for rebellion, identification and attitude: taking on the overpriced market leaders. Represents the mejo philosophy – fair prices without system dependency and without unnecessary extras.

ALUCOBOND® Composite material

Brand name for an aluminium composite material (dibond) with PE or FR (fire-retardant) core. Market leader among aluminium composite panels (ACP). mejo NNF® composite panel profiles are compatible with ALUCOBOND® in all common thicknesses (3–6 mm).

Dimensional tolerance Manufacturing

Permissible dimensional deviation for extruded profiles to DIN EN 755-9. Standard tolerance: normal (N) or precise (P). Example: width 40 mm normal ±0.3 mm. Tighter tolerances achievable by cold drawing (stretching) or CNC machining.

Aluminium alloy Material

Aluminium is enhanced by adding alloying elements (Mg, Si, Mn). In extrusion, the 6000 series (Al-Mg-Si) predominates. Key types: EN AW-6060 (good anodising quality, ~150 MPa), EN AW-6063 (similar to 6060), EN AW-6082 (high strength, ~260 MPa).

Anodising Surface

Electrochemical oxidation in sulphuric acid bath creates a hard Al₂O₃ layer (10–25 µm). Standard: DIN EN 12373. mejo NNK® default: Class 20 (20 µm).

Age hardening Heat treatment

Heat treatment step to increase strength. Distinction: natural ageing (T4, at room temperature) and artificial ageing (T6, controlled heating to 160–185 °C for 6–18 h). T6 gives maximum strength, T4 better formability.

BIPV Photovoltaics

Building Integrated Photovoltaics. Solar modules integrated into the building envelope as a constructive element: as façade cladding, roof covering or canopy. mejo NNS® large profiles are designed for BIPV façade applications.

Bauxite Raw material

Starting material for aluminium production. Bauxite is processed to alumina (Al₂O₃) via the Bayer process, then reduced to primary aluminium by smelting electrolysis. Energy-intensive: ~13.5 kWh/kg primary aluminium. Recycling requires only ~5% of this energy – a central sustainability argument for aluminium.

Bending stiffness Statics

Resistance of a profile to bending deformation. Calculation: EI (Young's modulus × area moment of inertia). High bending stiffness through: large pitch dimension, hollow chamber cross-section, EN AW-6082 T6. Guideline mechanical engineering: deflection f ≤ L/200.

BSP Profile system

Bosch System Profile – designation for machine construction profiles compatible with Bosch Rexroth® Aluminium Structural Framing. Pitch typically 45 mm, groove width 10 mm. mejo NNK® BSP is geometrically identical and up to 30% cheaper. Over 100 BSP geometries from Viersen warehouse.

CORAHEX® Composite material

Aluminium honeycomb composite panel similar to ALUCORE® – also with aluminium honeycomb core. mejo NNF® composite panel profiles are compatible with CORAHEX® in common panel thicknesses. Applications: façade, exhibition construction and vehicle construction.

CSP Profile system

C-Slot Profile – machine construction profiles with C-groove (semi-closed groove). mejo carries NNK® CSP in its range. C-groove advantages: higher transverse force absorption, concealed assembly, ideal for linear guides. From stock on request.

CBAM Compliance

Carbon Border Adjustment Mechanism – EU Regulation (EU) 2023/956. CO₂ border adjustment for imported aluminium from non-EU countries. From 2026, certificate obligation for importers. As mejo produces in Germany, no CBAM surcharge applies to mejo profiles. Emissions data on request: mejo.de/service/cbam.

C-groove Connection technology

Semi-closed profile groove – lateral opening narrower than the groove width inside. Advantage over T-groove: higher transverse force absorption, concealed assembly. Ideal for linear guides, high mechanical loads and CNC guide rails.

Composites Composite materials

Composite materials from multiple material layers. mejo offers: ALUCORE® (aluminium honeycomb core), CORAPAN® (PE core), STALUFLEX® (trapezoidal core), LUXBOARD (interior design) and KAALU®. All with aluminium face sheets. Applications: façade, interior, signage, exhibition construction.

Face sheet Composite materials

Outer aluminium layer in composite panels. Typically 0.3–0.5 mm thickness from EN AW-1xxx or 3xxx alloy. Can be anodised, powder coated (PE, PVDF) or film-laminated. The face sheets determine the surface properties and weather resistance.

DIN EN 755 Standards

European standard for extruded aluminium bars, tubes and profiles. Part 9 governs dimensional tolerances. Key parts: 755-1 (technical delivery conditions), 755-2 (mechanical properties), 755-9 (tolerances for profiles). Applies to all mejo NNK® stock profiles.

Deflection Statics

Deformation of a beam under load. Formula for simply supported beam, single load at mid-span: f = F·L³/(48·E·I). E = 70,000 MPa (aluminium), I = axial area moment of inertia from catalogue. Guideline mechanical engineering: f ≤ L/200. For optical constructions: f ≤ L/500.

Young's modulus Material science

Elastic modulus – describes the stiffness of a material in the elastic range. Aluminium: 70,000 MPa (70 GPa), independent of alloy. Comparison: steel 210,000 MPa. Aluminium is three times less stiff than steel, but only one third as heavy – the stiffness-to-weight ratio is similar.

Anodising Surface

Electrochemical process to create a hard Al₂O₃ layer (10–25 µm) by anodic oxidation in sulphuric acid. Hardness approx. 1,500 HV, electrically insulating, corrosion-resistant, scratch-resistant. Layer classes to DIN EN 12373: Class 10/15/20/25. NNK® standard: Class 20.

EN AW-6060 Alloy

AlMgSi0.5 – softest of the common extrusion alloys. Proof stress T66: approx. 150 MPa. Excellent anodising quality (uniform, clear oxide layer). Good weldability. Standard for NNK® profiles with surface requirements (visible constructions, façades).

EN AW-6063 Alloy

AlMg0.7Si – similar to EN AW-6060, slightly higher strength (T6: ~170 MPa). Also very good anodising quality. Frequently used for architectural profiles, window frames and façade profiles. Available from mejo on request.

EN AW-6082 Alloy

AlSi1MgMn – high-strength standard alloy in extrusion. Proof stress T6: approx. 260–280 MPa. Good weldability (MIG/MAG). More limited anodising quality than 6060/6063. Applications: load-bearing constructions, vehicle construction, heavy-duty profiles.

Extrusion Manufacturing

English and international technical term for Strangpressen (extrusion). Describes the process of pressing heated aluminium under pressure through a die. "Aluminium extrusion" is the common term in international industry. Synonyms: extrusion process.

Ground-mounted PV Photovoltaics

Photovoltaic installations on open ground (farmland, brownfields). Require robust substructures for wind loads. mejo NNS® large profiles are designed for ground-mounted installations.

Area moment of inertia Statics

Axial area moment of inertia I [mm⁴] – describes the resistance of a cross-section to bending. The further the material is from the neutral axis, the larger I. Hollow chamber profiles and large pitch dimensions have high I. Decisive for deflection calculation: f = F·L³/(48·E·I).

Mitre cut Machining

Angular sawing (0–45°) for flush corner joints without a visible cut edge. At mejo CNC-sawn with tolerance ±0.2°. Typical in exhibition construction (V-groove profiles) and for visually high-quality constructions. Alternative: face screwing (I-type connection).

Thread insert Connection technology

Also: Helicoil or ENSAT thread bush. Inserted into thin-walled aluminium threads to increase load capacity and screwing reliability. Recommended for M6 threads in wall thicknesses below 4 mm. mejo can install thread inserts on request.

Hollow chamber profile Profile geometry

Aluminium profile with one or more internal chambers. Higher area moment of inertia at less weight than solid profile. Advantage: better stiffness-to-weight ratio for bending applications. Disadvantage: more complex die design, poorer weldability. All NNK® construction profiles are hollow chamber profiles.

ISP Profile system

Item System Profile – designation for machine construction profiles compatible with item® aluminium profile system. Pitch typically 20–160 mm, groove width 5–10 mm. mejo NNK® ISP is geometrically identical to item® and fits all item® accessories. Over 260 ISP geometries from Viersen warehouse.

Pre-assembly Manufacturing

Pre-assembly of profiles: cutting to length, drilling to DXF specification, deburring, bundling and dispatch-ready packaging – all from one source. At mejo in-house for NNK®, NNS® and NNF® profiles as well as custom profiles.

Natural ageing Heat treatment

Heat treatment condition T4: natural ageing after solution annealing at room temperature. Takes days to weeks to reach maximum strength. Gives lower strength than T6, but better formability. Rarely used for extruded profiles – T6 and T66 predominate here.

Buckling Statics

Failure of slender compression struts by lateral deflection (Euler buckling). Decisive: buckling length sk and smallest moment of inertia Imin. Buckling load: Fk = π²·E·I/sk². For aluminium profiles as compression struts, maintain buckling safety factor of 2–3. Closed hollow profiles are more buckling-stable than open ones.

Corrosion resistance Material property

Aluminium spontaneously forms a dense oxide layer (Al₂O₃, 2–10 nm) that prevents further corrosion. Resistant to atmospheric corrosion, seawater (with protective layer), dilute acids. Anodising greatly strengthens this protection (20 µm Al₂O₃ instead of 2–10 nm). Avoid contact corrosion with steel using insulating layers.

Linear guide Linear technology

Mechanical guide for linear motion. Integrable in NNK® profiles via C-groove (for profile rails from INA, HiWin) or through milled fits. mejo supplies profiles with pre-drilled bolt patterns for all common linear guide systems.

Solution annealing Heat treatment

First step in heat treatment of age-hardenable alloys (6xxx). Profile is heated to ~530 °C, alloying elements (Mg, Si) go into solution. Followed by rapid quenching (air or water), then ageing (T6: artificial ageing, T4: natural ageing). In extrusion, typically carried out directly after the press.

Mounting rail Photovoltaics

Aluminium profile for fixing solar modules on roofs or open ground. mejo NNS® (No Name Solar®) is a system-independent mounting rail series: cross-brace, base profiles, flat roof and large profiles. EN AW-6060 T66, anodised or as-extruded. Compatible with all common PV mounting systems.

Die Manufacturing

Forming tool for extrusion – determines the cross-section of the profile. Made from high-strength hot work steel (H13). At mejo manufactured in-house in own die workshop – advantage: short development times (5–15 working days) and direct quality control. Tooling costs for custom profiles: typically €500–3,000.

No Name Frame® (NNF®) Profile system

Composite panel profile series from mejo – developed from 30+ years of practical experience as Germany's largest ALUCORE® dealer. Compatible with all common composite panels in panel thicknesses 6–25 mm. For architecture, vehicle and shipbuilding.

No Name Solar® (NNS®) Profile system

System-independent solar mounting rail series from mejo. Four product lines: cross-brace, base profiles, flat roof and large profiles. Compatible with all common PV mounting systems. EN AW-6060 T66, anodised silver Class 20. Cut to size and pre-drilled on request.

NNF® Profile system

No Name Frame® – composite panel profiles from mejo for the reception of composite panels (ALUCORE®, CORAPAN®, STALUFLEX® etc.). H-profiles, U-profiles and angle profiles with CNC-milled panel groove for play-free reception. Panel thicknesses 6–25 mm. CNC machining in-house.

NNK® Profile system

No Name Konstruktion® – machine construction profile own-brand from mejo. Compatible with item® (ISP) and Bosch Rexroth® (BSP). No system dependency: existing accessories fit directly. Up to 30% cheaper through direct delivery from press plant. Over 360 geometries from Viersen warehouse since 2010.

NNS® Profile system

No Name Solar® – solar mounting rails from mejo for PV substructures. System-independent, compatible with all common mounting clips and systems. Delivery cut to size and pre-drilled on request. EN AW-6060 T66, anodised silver Class 20 or Class 25.

T-nut Connection technology

Rectangular or T-shaped connecting block for the longitudinal groove of construction profiles. Groove widths 5, 6, 8 and 10 mm. Variants: standard T-nut (must be inserted from profile end), spring T-nut (rotated in, self-locking), hammer T-nut (tips in, can be inserted anywhere).

Grooved profile Profile geometry

Aluminium profile with one or more longitudinal grooves for the reception of connecting elements (T-nuts, guide rails, cable duct). T-groove (open), C-groove (semi-closed) and V-groove (decorative). Basic principle of all NNK® machine construction profiles.

Oxide layer Material property

Natural passive layer of aluminium oxide (Al₂O₃) on all aluminium surfaces. Thickness 2–10 nm, forms spontaneously in air. Protects against further corrosion (self-passivation). Anodising artificially thickens this layer to 10–25 µm for improved protection. Destroyed by strong alkalis (pH > 11) and chlorides.

Billet Manufacturing

Cylindrical aluminium block used as the starting material for extrusion. Heated to approx. 480–520 °C and pressed through the die under high pressure (400–8,000 t). mejo uses a network of over 30 presses in Turkey, Italy, Spain, Thailand and China.

PE core Composite materials

Polyethylene core in sandwich panels (e.g. CORAPAN®). Two aluminium face sheets (0.3–0.5 mm) are bonded to a solid PE plastic core. Result: lightweight, formable, cheaper than honeycomb core. Typical thicknesses 3–6 mm. Good for signage, signs and simple façade applications.

Profile groove Profile geometry

Longitudinal groove in aluminium profiles for connection technology, linear guides or cable routing. Determines accessory compatibility: groove width 5 mm (pitch 20/25), 6 mm (pitch 30), 8 mm (pitch 40/45), 10 mm (pitch 50+). Groove shape: T-groove (open), C-groove (semi-closed), V-groove (decorative).

Powder coating Surface

Colour application by electrostatically charged colour powder, cured at 180–200 °C. Layer thickness 60–80 µm. Almost any RAL colour possible. Robust colour film, UV-resistant, scratch-resistant (less than anodising). PVDF quality for highest weather resistance (30+ years).

PVDF Surface

Polyvinylidene fluoride – high-quality coating for aluminium façades and composites. Melting point 175 °C, excellent UV resistance and colour stability for 30+ years. Standard: EN 13523 (QUALICOAT Class 2). Standard for CORAPAN® and ALUCORE® for architectural applications.

Pitch dimension Geometry

Outer cross-section dimension of the profile, e.g. 40×40 mm or 80×40 mm. Determines groove width and compatible accessories. Common pitch dimensions: 20, 25, 30, 40, 45, 60, 80, 120, 160 mm. All NNK® profiles follow the pitch dimensions of item® and Bosch Rexroth®.

REACH Compliance

European Chemicals Regulation (EC No 1907/2006). Registration, Evaluation, Authorisation and Restriction of Chemicals. SVHC substances (substances of very high concern) must be declared above 0.1% by weight. All mejo profiles are REACH-compliant. Declarations on request.

Recyclability Sustainability

Aluminium is recyclable to nearly 100% – without loss of quality. Recycling requires only approx. 5% of primary production energy (~0.7 kWh/kg vs ~13.5 kWh/kg). In Europe, over 90% of all aluminium profiles are recycled at end of life. Central sustainability argument for aluminium as a construction material.

RoHS Compliance

Restriction of Hazardous Substances – EU Directive 2011/65/EU (RoHS 2), revised by 2015/863 (RoHS 3). Restricts lead, cadmium, mercury, Cr(VI), PBB, PBDE in electrical equipment. All mejo profiles: lead-free, cadmium-free, Cr(VI)-free – fully RoHS-compliant.

Special profile Manufacturing

Individual cross-section geometry beyond the standard range – developed to customer requirements. Synonymous term for custom profile. mejo has been a specialist for aluminium special profiles since 1932 – the company's largest business area. Minimum quantity approx. 500 kg, own die workshop.

Sandwich panel Composite materials

Composite panel from two face layers and a core. Principle: separation of face sheets by the core increases the area moment of inertia with minimal weight (like an I-beam). At mejo: CORAPAN® (PE core) and ALUCORE® (aluminium honeycomb core). Applications: façade, exhibition construction, interior.

Proof stress Material property

Stress at which a material permanently plastically deforms (Rp0.2 to DIN EN ISO 6892). For aluminium extruded profiles: EN AW-6060 T66 approx. 150 MPa, EN AW-6082 T6 approx. 260–280 MPa. Decisive for load capacity calculation. Not to be confused with tensile strength (Rm is always higher than Rp0.2).

Extrusion process Manufacturing

Manufacturing process for aluminium profiles: heated billet (approx. 480–520 °C) is pressed under high pressure (400–8,000 t at mejo) through a profile-shaped die. Enables complex hollow chamber cross-sections in one step. Most economical process for profiles up to 6 m length from approx. 500 kg series quantity.

System dependency Procurement

Binding to a proprietary manufacturer for accessories and extensions. item® and Bosch Rexroth® are system manufacturers – accessories are only compatible with their own system. NNK® from mejo is deliberately system-free: geometrically identical, but no system surcharge, no dealer obligation. Existing accessories from other manufacturers remain usable.

T6 / T66 Heat treatment

Heat treatment conditions for aluminium. T6: solution annealed + artificially aged – maximum strength (EN AW-6082 T6 ≈ 260 MPa). T66: like T6, but with tighter tolerance on mechanical properties – typically EN AW-6060 T66 (≈ 150 MPa). "T" stands for "thermally treated", the number designates the specific process sequence.

T-groove Connection technology

Open longitudinal groove with T-shaped cross-section. T-nuts can be inserted at any position – flexible assembly, infinitely adjustable. Standard for NNK® ISP profiles. Disadvantages compared to C-groove: slightly lower transverse force absorption, groove open (possible dirt accumulation).

Tolerance class Manufacturing

Specifies the permissible dimensional deviation. Extruded profiles: normal (N) and precise (P) to DIN EN 755-9. CNC machining at mejo: length ±0.1 mm, drilling to DIN ISO 2768-m (±0.1 mm for Ø up to 30 mm), precision drilling up to H7 (±0.015 mm) on request.

VSP Profile system

V-Slot Profile – machine construction profiles with V-groove (45° chamfer). mejo carries NNK® VSP in its range. Typical application: exhibition construction and display systems with concealed screwing and clean mitre joint. Anodised silver is the standard for visible constructions.

Composite panel Composite materials

Panel-shaped composite material from multiple layers. In the aluminium sector: aluminium face sheets + core (PE, honeycomb, steel). Properties: lightweight, dimensionally stable, good thermal insulation. mejo products: ALUCORE®, CORAPAN®, STALUFLEX®, LUXBOARD, KAALU®. Processing with NNF® composite panel profiles.

V-groove Profile geometry

Decorative 45° chamfer in the profile edge with no connection function. Enables optically clean mitre joints without visible screw heads (internal screwing). Typical in exhibition construction and interior fit-out. NNK® ISP profiles with V-groove, anodised silver: standard for high-quality display systems.

Die workshop Manufacturing

Manufacturing of extrusion dies for individual profile cross-sections. mejo produces dies predominantly in its own die workshop and carries out corrections almost exclusively in-house. Advantage: short throughput times (5–15 working days), direct quality control.

Honeycomb core Composite materials

Honeycomb-shaped aluminium structure as core material in ALUCORE® composite panels. Hexagonal cells from 0.05–0.1 mm aluminium foil. Result: extremely lightweight (air content >95%), very high bending stiffness, good sound insulation. Weight 3–6 kg/m² at total thicknesses of 10–30 mm.

Wall thickness Profile geometry

Material thickness of the profile wall in hollow chamber and tube profiles. Typically 1.5–6 mm for standard construction profiles. Influences: weight, area moment of inertia, weldability and machinability. Minimum wall thickness in extrusion: depends on pitch dimension and alloy, typically ≥ 1.0 mm.

Heat treatment Manufacturing

Controlled temperature management to influence mechanical properties. For aluminium extruded profiles: solution annealing (530 °C) → quenching → ageing (T6: 160–185 °C for 6–18 h). Result: Mg₂Si precipitates in the microstructure increase strength. mejo profiles are supplied with factory heat treatment.

Custom profile Manufacturing

Individual aluminium profile to customer drawing or CAD file. mejo manufactures die in own workshop (5–15 working days), first samples 2–4 weeks after release, series 3–4 weeks after sample release. Economical from approx. 500 kg/pressing. Advantage: integrated functions replace additional parts and machining steps.

Tensile strength Material property

Maximum stress a material withstands before fracture (Rm to DIN EN ISO 6892). For aluminium extruded profiles: EN AW-6060 T66 approx. 195 MPa, EN AW-6082 T6 approx. 310 MPa. Always higher than proof stress (Rp0.2). For design calculations, proof stress is generally used, not tensile strength.