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A guide to machining plastic turned parts

Plastic is a versatile material used for turned parts which APT regularly machines. But what are the different types of materials used and why is plastic a good choice? In this article, we’ll explain why plastic turned parts could be a good option for manufacturing businesses.

Acetal rods for plastic turned parts

What are the pros of plastic turned parts?

Plastic machining can often be overlooked in favour of metal machining, but this material offers various benefits. Plastic machined parts have good friction factors and offer greater corrosion resistance, which makes it ideal for guides, nozzles and brushes. Plastic can be machined precisely and intricately at various volumes to a vast range of designs.

What are the cons of plastic turned parts?

Plastic machining is not always cheaper than metal or faster to produce. In fact, some plastics are more expensive than metal due to the useful qualities and applications of this material. Feeds and speeds need to be matched to the type of plastic being machined. When it comes to CNC machining fluid, this still needs to be used as the process gets hot and needs to be flushed. Plastic machining tools are also subject to wear over time, too.

What are the different plastics that can be machined?

There are hundreds of plastics used for machining. But there are some specialist materials that have a useful combination of qualities, which makes them suitable for certain turned parts and components. The most common plastics are Delrin, Acetal, Nylon, PTFE, PEEK and Tufnol.

There are three leading types of plastic machining materials:

1. Delrin

Delrin is a tough, rigid plastic, providing mechanical strength and high resistance to repeated impacts and long-term fatigue. This plastic offers outstanding resistance to moisture, solvents, and various neutral chemicals.

2. Acetal

Acetal offers excellent wear characteristics, fatigue resistance, low friction and low water absorption. This plastic is a useful material for wet and dry environments, electrical components, and exposure to hydrocarbons and solvents.

3. PEEK

PEEK is a strong plastic at elevated temperatures and offers good chemical resistance. This plastic has bone-like traits, which makes it ideal for a range of uses, including within the medical sector and for prosthetics.

What industries rely on plastic turned parts?

There are a broad range of industry sectors that use plastic as an integral part of their manufacturing or engineering processes. These include but are not limited to Aerospace, Automotive, Medical & Optical, Military & Defence, Chemical, Oil & Gas, Food & Packaging.

The top three sectors that rely on plastic turned parts are:

1. Pneumatics
2. Electronics
3. Motorsport

How is plastic machined?

Depending on the type of plastic turned part required, there are different options available:

Mill Turning, for machining different shapes.
Threading, to create a variety of screw threads.
Boring, to make cylinders, pipes and assemblies.
Broaching, for machining holes, teeth and keyways.
– Other processes include: Drilling, Grooving, Counterboring, Knurling.

What parts can APT produce in plastic?

APT can machine plastics in a range of sizes with the current smallest diameter being approx. 2mm and the largest at 42mm. Plastic machined parts can be produced using Acetal, Nylon, PTFE, PEEK and Tufnol. There is capacity for 65mm in diameter from bar, and up to 300mm in diameter for billet work. To date, the longest plastic turned part was approx. 250mm and APT Leicester has achieved tolerances of +/- 0.1mm.

Considering plastic turned parts?

Plastic is a good option for your manufacturing needs due to the good friction and low corrosion factors.

Need advice about the suitability of plastic for your application? For further info or a quote for plastic machined parts, prismatic milled parts or CNC plastic machining, please contact our team or call APT Leicester today on 0116 287 0051.