Technical Advice

Our experts are at your service so as you may be given advice about any technical question that might come up regarding Hard Anodizing.

Design considerations of pieces for Hard Anodizing:

• SELECTION OF THE ALUMINIUM ALLOY
• DIMENSIONAL CHANGE
• SURFACE FINISH: Polished, grit blasted, vibration … Being the wear resistance critical, the previous surface finish must have the least possible roughness.
• CONTACT POINTS: When hard anodizing finish required on the piece, the electrical contact points are befitted to be settle on from the design.
• LAYER UNIFORMITY: evaluate the necessity of having a uniform layer in holes and blocked out areas.
• SHARP EDGES AND BURRS: Avoid burrs and sharp edges, as in those points the anodic layer may go off. The MIL-A-8625 F regulation establishes some minimum radius of curvature ends depending on the layer thickness:

  Nominal layer thickness (millimetres)	Curvature radius
  0.0254	0.793 mm.
  0.0508	1.587 mm.
  0.0762	2.381 mm.
  0.1016	3.175 mm.

• ROUGHNESS INCREASING: Ra grows up from 0,3 to 0,6 (depending on the alloy and the layer thickness).
• SURFACES TO BE MASKED: holes, threads, earth connection point...
• OTHER METALS: Steel inserts or other metals not to be anodized are damaged within anodizing unless previously covered.
• BLENDS OF ALLOYS: when possible avoid the blending of alloys, as its simultaneous anodizing causes dispersion on layer thickness due to its different pattern.
• DEFECTS: Scratches, marks, stains, corrosion, welds... Anodic coatings don’t make up the finish imperfections.
• CORROSION RESISTANCE: Contact with other corrosive products with PH between 3 and 9,5. must be avoided.