Diffusers, Grilles & Louvres - Please contact us directly on 0161 336 5065 for bespoke products not listed as we specialise in made-to-measure vents and custom designs.

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FAQ's

What size vent should I buy?

The air flow required often determines which size of vent is suitable. Resistance factors such as blades or dampers should also be considered when calculating the required grille size - angled blades will create more resistance than straight blades for example.

What finish can I have?

One of the most important factors to consider is the finish. Most standard finishes are Mill Aluminium or White RAL9010.  

Aluminium Vents can also be provided in anodised or powder coated to match any RAL/BS colour reference.

 

What is "Mill Finish" ?

Aluminium Mill Finish: A Finish or Not?

It is generally accepted that aluminium is a long lasting lightweight metal with minimal on-going maintenance requirements.

There are many different surface finishes that can be applied to enhance the appearance of aluminium; anodising, powder coating and satin brushing are just three examples.

However mill finish aluminium is not one of them! Mill finish is not an applied finish but simply untreated aluminium.

For whatever reasons some names just stick; Escalator for moving stairway; JCB for excavator etc., and mill finish for unfinished aluminium. This term often raises expectations and mistakenly leads the unwary into expecting an immaculate surface finish. So we will attempt to close the knowledge gap when it comes to the appearance of mill finish aluminium.

Aluminium Mill Finish

Once the extrusion or rolling mill has manufactured the aluminium into the desired shape and size the material is said to be in the “mill finish” condition. So what are the visual characteristics of untreated aluminium? Extruding aluminium, as opposed to rolling sheet, produces differing surface finish effects so let’s consider them separately.

Aluminium Extrusions

Aluminium extrusions are produced by either pushing or pulling the material (in a heated/softened state) through a hardened steel die. This process produces both simple geometric shapes (aluminium angle, channels, etc.,) and the more complex ‘purpose made’ designs. All of these forms normally display longitudinal lines of varying width, texture and tone. Various surface abrasions may also be apparent. The standard architectural grade (6063) is normally quite shiny and this tends to highlight such features.

Despite these factors there are many instances where mill finish is successfully incorporated into a large number of projects (both seen and unseen). It is usually only when surfaces are going to be viewed at close quarters, either in aesthetically demanding situations or in particularly ‘aggressive’ atmospheres , that this industrial finish benefits from a finishing operation of some kind.

Aluminium sheet is produced in a similar way to flattening pastry with a rolling pin. The constant backwards and forwards rolling process reduces the material to the required gauge thickness and temper (hardness) and in so doing the sheet becomes ’polished’ to some degree. The alloy mix of the aluminium will also affect the materials’ brightness and reflectivity. Sheets will sometimes display rolling bands or stripes and may also commonly possess a grainy type finish.

A finer surface appearance can normally be achieved by selecting anodising or architectural quality aluminium. Our industry recognises that items required for these applications require a higher surface finish standard as opposed to general commercial applications.

In summary, aluminium materials that are going to be closely scrutinised would usually benefit from an applied surface finish. However there are many applications where mill finish is perfectly acceptable.

Remember we are happy to provide a sample (subject to quantity required) of any of grille in any finish to help you make a decision.

For more information on Mill Aluminium or any other finishes please speak to our sales team on 0161 336 5065.

Do you have a colour matching service?

For those colours that do not fall into the RAL/BS range, we offer a paint-matching service. Just email or call with the details of the paint to be matched, try to include:

  • Manufacturer
  • Colour Name
  • Matt/Gloss/Satin/Egg Shell

If you have a small sample of the tile, wood/metal frame etc, simply post it to us and we will do the rest.

We can even match finishes to designer paint ranges such as Little Greene, Farrow & Ball etc.