What materials do you stock for CNC machining?

Metals stocked for CNC machining

Aluminium alloy grade 6082 – A medium-strength alloy with excellent machinability and corrosion resistance.

Aluminium alloy tooling plate grade 5083 – A fine-grained, homogenised alloy with excellent flatness and dimensional stability, and good chemical resistance.

Stainless steel AISI grade 304 – Also known as A2 stainless steel or 18/18 stainless steel, this is a versatile grade that has excellent corrosion resistance (except in chloride environments) and is non-magnetic (unless it has been cold-worked). Better machinability than 316 stainless steel.

Stainless steel AISI grade 316 – Also known as A4 stainless steel or ‘marine grade’ stainless steel. Excellent corrosion resistance, suitable for medical devices, laboratory equipment and applications in the food, pharmaceutical and chemical industries. Non-magnetic (unless work hardened).

Engineering plastics stocked for CNC machining

Acetal, black and natural – Also known as polyacetal, polyoxymethylene (POM), polyformaldehyde and Delrin, this is strong, rigid and tough, with low friction and excellent machinability. It is resistant to creep, fatigue, moisture and chemicals, and possesses good electrical properties.

Clear acrylic – Also known as PMMA (polymethyl methacrylate) and trade names such as Opitix, Plexiglas and Acrylite, this has excellent optical clarity; after machining, it can be polished to give a glass-like appearance. Acrylic also has excellent strength, stiffness and dimensional stability

Clear polycarbonate – This material is superior to acrylic in terms of impact resistance, abrasion resistance and temperature resistance. Polycarbonate (PC) has high strength, dimensional stability, electrical resistance, good machinability and can be repeatedly steam sterilised. However, it is sensitive to prolonged exposure to hot water, fatigue resistance is poor and it is resistant to only a limited range of chemicals.

Stock sizes

The above materials are stocked in the form of blanks for 3-axis or 5-axis CNC milling:

• 150 x 50 x 40 mm
• 100 x 50 x 40 mm
• 50 x 50 x 40 mm

In addition, we have bar stock of these materials in a range of diameters up to 60 mm for CNC turning:

• Aluminium 6082
• Stainless steel 304 and 316
• Acetal, black and natural
• Clear acrylic

What about non-stock materials and sizes?

If you need a part in another material, or a part machined from a different size of blank or bar stock, we can source the material and machine it. However, in this case we cannot offer Express CNC machining.  Our lead time will be based upon material availability and production time.

Materials that we typically source on request for CNC machining include copper, brass, phosphor bronze, mild steel, tool steel, ABS, ABS/PC, HDPE, PBT, PEEK, PEI, PET, PP, PPSU, PSU, PTFE and PVC.

Less commonly, we also source and machine materials such as Tufnol composites, Styrofoam and other modelling foams, and polyurethane or epoxy tooling boards. A few materials, including ceramics and exotic alloys, require specialist tooling, so we outsource this machining to a trusted subcontractor.

Materials for small batches of parts

With our new fully automated, robot-tended 5-axis machining centres, we are well placed to produce small batches of parts. To maximise the efficiency of the overall production process, blanks are sized appropriately. If you need a batch of parts, contact us with your requirements and we will quote a price and lead time that includes sourcing the material and preparing the blanks.

Talk to us

If you want to discuss CNC machining, need more information about the materials we hold in stock or can source, or would like a material sample pack, call us on 01763 249760 or complete the enquiry form below.