Answers to common questions


What does the aluminium extrusion process involve?

Aluminium extrusion is a process of transforming lengths of aluminium alloy from billet into specific shapes objects with a particular cross-section. Aluminium lengths are pushed through an extrusion die with a smaller cross sectional area than the billets themselves, taking on the shape required. The aluminium extrusion process is a relatively quick, simple and cost-effective one, with aluminium perfectly suited, due to its versatility, to this kind of forming.

What are aluminium extrusion profiles? 

Aluminium extrusion profiles are the lengths of product that are ultimately created during the process of extrusion. Aluminium extrusion profiles come in an infinite range of solid and hollow shapes, the most common being square tubes, L-shaped channels and t-slot lengths.

What’s the longest extruded aluminium profile you can supply? 

We supply a wide range of extruded aluminium profiles to our customers up to 11.5 metres in length with our in-house Mecal 5-axis CNC machine. 

Where do your source aluminium from? 

As you’d expect from a business that has purchased thousands of tonnes annually for thirty years, you can be assured we have a reliable, global supply including the UK which we actively promote and are very proud of.

And with decades of experience in buying, supplying and machining aluminium extrusions for a range of sectors, we pride ourselves on securing raw material at the best possible price so we can pass on savings to customers. 


What is aluminium anodising?

Aluminium extrusion is a process of transforming lengths of aluminium alloy from billet into specific Anodising is a process for producing decorative and protective films on articles made from aluminium and its alloys. Aluminium alloys are anodised to increase corrosion resistance and to allow dyeing (colouring), improved lubrication, or improved adhesion. However, anodising does not increase the strength of the aluminium object. The anodic layer is insulative.

Can you anodise aluminium at Sherwood? 

We work with a global network of specialist partners to supply our customers with a range of custom aluminium anodising services. All conform to the ISO 9001 accreditation system and we ensure all work is undertaken to our own exacting standards.

A continued investment allows us to support customers who require fabrication that meets salt spray and corrosion resistant materials under British Standards. We offer a wide range of available colours that follow the industrial colour chart including bespoke colours, RAL Colours and BS 4800 Colours.


What is the difference between fabrication and extrusion?

Aluminium extrusion refers to the process of forcing an aluminium billet through a die in order to change its profile (into a tube, or a bar, or H-profile). Aluminium extrusion fabrication is the manufacturing of these extruded aluminium profiles. That means doing some extra machining such as punching some holes or welding it.

How does CNC machining work?

CNC machining works by taking information entered into a computer and converting the data into electrical signals. These signals are sent to the motors within the CNC machining centre, and control the various mechanisms contained within it. The tools then carry out the process of machinery much more delicately than would be possible by hand.

What additional post-fabrication services does Sherwood offer? 

Sherwood offers a number of post-extrusion fabrication services, predominantly centred around CNC machining (drilling, milling, bending, punching turning, cut to length and mitring. 

Some of these services are carried out by our in-house experts in Wolverhampton, other members of the Sherwood Group or by trusted supply partners. In all cases, we manage the entire process ensuring you receive the highest quality product finishes.

CNC Machining

How does CNC machining work?

CNC machining (computer numerical machines) is based on computer data being converted into electrical signals that are sent to motors within a CNC machining centre. The signals control all the mechanisms within the tool to manage the job being machined. The tools then carry out the process of machinery much more delicately than would be possible by hand.

Is CNC machining the most accurate approach for aluminium extrusion? 

CNC machining processes are improving all the time. Standards are exceptionally high, meaning we can achieve very precise results. As an example, our four-axis CNC machining centres can achieve tolerances of up to 0.1mm, although the specific tolerances we’ll be able to meet for your will depend on its specification.

What CNC capability do you have on-site? Do you have 5-axis capability? 

Sherwood offers 3-axis, 4-axis and 5-axis machining across multiple sites, allowing us to work on a range of shapes and surfaces, and carry out a wide variety of tooling processes, including some intricate techniques.

Twelve 3-axis Bridgeports run the bulk of the business. Three Haas 1.6m 4-axis and two Emmergi 7.5m 4-axis machines support for demanding projects and our Mecal 11.5m 5-axis works at long length. 

With over eighteen machines in Wolverhampton alone, supported by additional capability across the group, means we can comfortably meet most customer requirements.

Find out more about our range of CNC machining services here.