Plastic CNC machining

ISO 9001 Certified
JOSCAR Registered
MAKE UK Defence Member
Ben
Aerospace & Industrial
Penta Precision delivered an excellent service with a standard turnaround. The work was of a sublime level and the level of communication right from the start was outstanding.
Simon
Industrial & Marine
Penta provide an excellent service from start to end. Friendly and knowledgeable consultant and advice, superb communication throughout, outstanding attention to detail, flawless engineering and machining, on time supply, transparent pricing, clear and accurate paperwork. A genuine pleasure to do business with.
Steve
Steve, Scientific and Technical
Excellent service, friendly and helpful staff. Never had a non-conformance on our system for Penta Precision.
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Experienced. Certified. Trusted.

Plastic machining specialists

We provide high-quality plastic machining UK services for companies that require accuracy, repeatability and trusted supply. Our advanced milling and turning capabilities allow us to deliver CNC plastic machining solutions across a wide range of engineering plastics, including acetal, nylon, PEEK, PTFE, UHMWPE and acrylic.

British Assessment Bureau ISO 9001 Quality Management Accreditation
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Machined plastic components, your way

With dedicated milling and turning cells, we produce reliable plastic machined parts that meet even the most demanding requirements.

From tight tolerance bushings and housings to complex milled components, our processes are optimised to maintain surface quality, minimise distortion, and ensure long-term stability. Every job undergoes in-process checks and final inspection for dependable results.

Examples of our high-quality machined plastic parts

Filter

Plastic machining
CNC Turning
PTFE

Baffle cage support bracket

Plastic machining
CNC Milling
Nylon

Plastic Turned Component

Plastic machining
CNC Turning
Engineering Plastic

Acetal tooling

Plastic machining
CNC Turning
Black delrin

Threaded component

Plastic machining
CNC Turning
Engineering plastic

Enclosure component

Plastic machining
CNC Milling
Polycarbonate

Our machining services

View all services
View all services

Guidelines for plastic CNC machining

Tab one

Order Type Quantity Range Typical Lead Time Additional Info
Prototype 1–5 parts 1–4 weeks* May vary based on complexity and material, but is flexible to the part requirements. Contact us early to discuss.
Small Batch Production 6–25 parts 4–6 weeks Can occasionally be reduced to 2–3 weeks depending on capacity and material lead time.
Medium Batch Production 26–100 parts 4–6 weeks Best suited to scheduled or call-off ordering for consistency
High Volume Production 100+ parts 4–6 weeks Longer lead times. Kanban or call-off ordering strongly advised
Kanban / Call-Off Orders Varies 24–48 hours dispatch* Stock held at Penta. Dispatch triggered by usage or schedule. Order is invoiced or paid upon call-off.
Tab two

Process Range of Tolerances Achievable Notes
Milling >±0.015 Dependent on part geometry, setup. 5-axis offers tighter tolerances and better repeatability. Plastic parts are measured at ambient room temperature.
Turning >±0.02+ mm High-precision turning across billet and bar work, supported by modern multi-axis machines.
Geometric Tolerances >±0.005+ mm* *Depending on material, finishes, and the geometry of the part.
CMM Measurement Verification to ±0.002 mm Achieved using our Axiom Too CMM with 2.3µm volumetric accuracy and temperature compensation.
Tab three

Finishing Process Purpose Additional Information
Vapour Polishing Improves the surface clarity and smoothness of plastic parts by reflowing the surface using solvent vapour. Commonly used on polycarbonate and acrylic components to restore transparency and achieve a gloss finish. Ideal for optical, display, or fluid-handling applications.
Ultrasonic Cleaning Removes fine particles, oils, and machining residue using high-frequency sound waves. Commonly used as a pre-finishing or pre-assembly process. Ideal for complex geometries and internal features. Leaves no residue.
Assembly Combines multiple components into a finished or semi-finished assembly. Used to streamline production workflows. May include press fitting, fasteners, inserts, or other mechanical joining methods.
Tab four

Process Maximum Dimensions Notes
Milling Up to X: 1000 mm, Y: 600 mm, Z: 550 mm Based on Doosan and Matsuura 5-axis machines. Max Ø350 mm × 300 mm height for 5-axis work.
Turning Max billet Ø380 mm × 580 mm length
Max bar Ø65 mm × 1100 mm length
Applies across Mazak, Doosan Puma, and CMZ lathes. Includes Y-axis and driven tooling.
Tab five

Common industry applications

Electronics & computing

Electronics & computing

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Pharmaceutical & medical

Pharmaceutical & medical

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Defence & Military

Defence & Military

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Food processing & packaging

Food processing & packaging

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Automotive & Transport

Automotive & Transport

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Plastic CNC equipment we use

Matsura MAM72-35V

Automated 5-axis CNC Milling
Max. Work Size: Ø350 mm x H300 mm
Travel X / Y / Z: 550 / 440 / 580 mm
32 pallets, 240 cutting tools

Doosan VC630 5AX

5-axis CNC Mill
X-Axis Travel: 650 mm
Y-Axis Travel: 750 mm
Z-Axis Travel: 500 mm

Mazak Quick Turn 200MY

CNC Lathe
Chuck size: 8"
Max. machining dia: Ø380 mm
Max. processing length: 38 mm / 1047 mm

Doosan Puma 2600SY

CNC Lathe
Max bar dia: Ø65 mm
Max bar length: 1100 mm
Max billet dia: Ø270 mm

CMZ C20 YS

CNC Lathe
Max bar dia: Ø65 mm
Max bar length: 1050 mm
Max billet dia: Ø230 mm

CMZ TL20 MS

CNC Lathe
Max bar dia: Ø65 mm
Max bar length: 1100 mm
Max billet dia: Ø270 mm

Mazak Quick Turn 100M

CNC Lathe
Chuck size: 6"
Max. machining dia: Ø280 mm
Max. processing length: 340 mm

CMZ TL20 MS

CNC Lathe
Max bar dia: Ø65 mm
Max bar length: 1000 mm
Max billet dia: Ø350 mm

Doosan DNM 500

5-axis CNC Mill
X-Axis Travel: 1000 mm
Y-Axis Travel: 500 mm
Z-Axis Travel: 500 mm

Doosan DNM4500 4AX

5-axis CNC Mill
X-Axis Travel: 800 mm
Y-Axis Travel: 450 mm
Z-Axis Travel: 510 mm

Bridgeport VMC1000 4AX

4-axis CNC Mill
X-Axis Travel: 1000 mm
Y-Axis Travel: 600 mm
Z-Axis Travel: 600 mm

Bridgeport VMC 760

CNC Mill
X-Axis Travel: 760 mm
Y-Axis Travel: 600 mm
Z-Axis Travel: 480 mm

Bridgeport XR1000

CNC Mill
X-Axis Travel: 1000 mm
Y-Axis Travel: 600 mm
Z-Axis Travel: 600 mm

Bridgeport VMC 600 4AX

CNC Mill
X-Axis Travel: 600 mm
Y-Axis Travel: 400 mm
Z-Axis Travel: 350 mm

Bridgeport VMC 500

CNC Mill
X-Axis Travel: 550 mm
Y-Axis Travel: 350 mm
Z-Axis Travel: 350 mm

What our clients say

Leanne
Senior buyer at bicycle firm
We’ve worked with Penta on several complex projects, and their consistency and attention to detail have been second to none. The team is quick to respond and flexible.
Andrea
Buyer
Penta is highly recommended for their quality, responsiveness and customer service. We have experienced a lot of change with our parts and Penta has always accommodated the adjustments needed in a timely manner. The quality is 100%.
Mark
Senior buyer at coffee brand
The quality of the plastic mouldings you machined were exceptional.

More about plastic CNC machining

Article

Medical plastics machining: Guide to choosing the right types

Plastics can be harder to machine than metals: they can be less forgiving. Machining plastics requires specialist expertise – the kind that comes only with years of experience. But that's just half the battle. Not every plastics machining specialist has the experience needed to meet the stringent requirements of medical equipment OEMs. Choosing the right machining partner for medical applications is vital to ensure quality, consistency, validated processes and traceability of materials.

Common questions