CNC machining service

Penta Precision is a trusted provider of CNC machining services in the UK, delivering high-quality CNC machined components with care and consistency.

Our CNC machining service is built on precision, reliability, and clear communication, supporting customers across industries including aerospace, medical, defence, and manufacturing. Whether you need one-off custom CNC parts or high-volume CNC components, we work with you to ensure the right outcome for your project.

We machine a wide range of CNC machining materials, including aluminium, stainless steel, and engineering plastics. With advanced capabilities including 5 axis CNC machining and automated production, we’re equipped to handle projects of all sizes and complexities. If you’re looking to get CNC parts made and want a team that prioritises quality and service, Penta is here to help.

CNC machining capabilities 

We offer a wide range of CNC machining services, from one-off prototypes to full production runs. Our capabilities include CNC milling, CNC turning, and 5 axis CNC machining using advanced technology and highly skilled engineers. With a focus on quality, accuracy, and reliability, we deliver CNC machined components that meet exact specifications every time, making it easy to order CNC parts with confidence.

Guidelines for CNC Machining

Lead times

CNC tolerances

Finishing processes

Max dimensions

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 >±0.01 mm Dependent on part geometry, material and setup. 5-axis offers tighter tolerances and better repeatability.
Turning >±0.005+ 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
Hard Anodising Adds a protective oxide layer to aluminium parts. Usually 25–30 microns thick. Typically used for parts designed for the outdoors and general engineering for corrosion resistance. This finish requires hole masking and machining allowance, so use only if needed.
Sulphuric Anodising Adds a decorative layer to aluminium. Less than 5 microns thick. Won’t offer any protection and minimal corrosion resistance. For decorative or aesthetic purposes only.
Bead Blasting Creates a uniform matte finish that removes tool marks. Ideal for reducing reflectivity and improving surface uniformity.
Powder Coating Provides a hard, colourful coating that is tough and wear-resistant. Commonly used on enclosures, brackets, and consumer-facing components.
Chromate Conversion Plating Enhances corrosion resistance while retaining electrical conductivity. Often applied to aluminium components used in electronic assemblies. Commonly referred to as Surtec or Iridite.
Polishing Achieves a smooth, high-quality surface for aesthetic or functional use. Used in medical, optical, or high-spec applications where surface finish is critical.
Nickel Plating Applies a thin layer of nickel to improve corrosion and wear resistance. Provides a bright, uniform finish. Often used for decorative parts or where moderate hardness and conductivity are needed.
Zinc Plating Adds a protective zinc layer to prevent rusting, especially on steel parts. Usually applied with a clear, yellow, or black passivate. Cost-effective option for corrosion resistance in less aggressive environments.
Burnishing Improves surface finish and work-hardens the material through controlled deformation. Produces a smooth, polished surface without material removal. Enhances fatigue strength and aesthetic appearance.
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

CNC equipment we use

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What components can we machine?

We machine a wide variety of CNC parts to suit different functions, performance requirements, and environments.

From structural brackets to fluid-handling manifolds, our team produces high-quality CNC machined components across many industries. We work with both plastics and CNC machining metal materials to meet varied customer requirements.

Structural parts

Brackets, supports, frames, and panels that require rigidity and dimensional accuracy.

Rotating & moving components

Shafts, bushes, gears, and 
linkages designed for motion 
and wear resistance.

Protective & housing parts

Enclosures, covers, guards, and casings that protect sensitive internal components.

Heat & fluid management

Heatsinks, manifolds, flow plates, and fittings for thermal or fluid control applications.

Precision & custom components

Specialist or tight-tolerance parts including jigs, fixtures, prototypes, and custom CNC components.

Examples of our high-quality CNC machined components

Interact in 3D

Enclosure

Aluminium machining
CNC Milling
Aluminium nickel bronze
Interact in 3D

Filter

Plastic machining
CNC Turning
PTFE
Interact in 3D

Materials testing component

Brass machining
CNC Turning
Brass with nickel coating
Interact in 3D

Sequencing chamber

CNC Milling
Aluminium
Interact in 3D

Filter

Plastic machining
CNC Turning
PTFE
Interact in 3D

Enclosure

Aluminium machining
CNC Milling
Aluminium nickel bronze
Interact in 3D

Sequencing chamber

CNC Milling
Aluminium
Interact in 3D

Rod

Brass machining
CNC Turning
Brass

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.

Common questions

How much does CNC machining cost?
Is there a minimum order quantity (MOQ)?
What is the fastest lead time you can offer?
What file formats do you accept for CNC machining?
What are the maximum and minimum part sizes you can machine?
Can I get a prototype before full production?