Boring Service | Precision CNC Internal Turning for Plastic Parts

Boring is a precision CNC machining process used to enlarge and finish internal holes in plastic components with high accuracy and smooth surface quality. Compared with standard drilling, boring provides tighter tolerances, improved concentricity, and better dimensional consistency. As a professional plastic parts manufacturer, we provide reliable custom CNC boring services for bushings, sleeves, housings, […]

Product Description

Boring is a precision CNC machining process used to enlarge and finish internal holes in plastic components with high accuracy and smooth surface quality. Compared with standard drilling, boring provides tighter tolerances, improved concentricity, and better dimensional consistency. As a professional plastic parts manufacturer, we provide reliable custom CNC boring services for bushings, sleeves, housings, tubes, and precision engineering plastic parts. Whether you require non-standard plastic machining or small-batch plastic parts customization, we deliver stable quality, precision tolerances, and efficient machining solutions.


Advantages of Boring

Our CNC Boring Process

Material Preparation

Plastic rods, tubes, or molded blanks are prepared and securely fixed to maintain machining stability and accuracy.


Pilot Hole Machining

Initial drilling or pre-machining creates the base hole before precision boring operations begin.


Precision CNC Boring

High-precision boring tools enlarge and finish the internal diameter to achieve the required tolerance, concentricity, and surface quality.


Finishing & Inspection

Additional finishing operations such as reaming, polishing, or threading are performed as needed, followed by dimensional inspection and quality verification.


Common Plastic Materials for Boring

MaterialKey BenefitsTypical Applications
POM (Acetal)Excellent dimensional stabilityPrecision bushings and sleeves
PA (Nylon)Wear resistance and toughnessMechanical housings and bearings
PTFELow friction and chemical resistanceSealing and sliding systems
ABSEasy machinabilityIndustrial components
Acrylic (PMMA)Transparency and rigidityOptical and display components

Industry Applications


Quality Control & Precision Manufacturing


Cost Optimization & Production Efficiency


Why Choose Us

As a trusted plastic parts manufacturer, we specialize in precision CNC boring, non-standard plastic machining, and small-batch plastic parts customization. From material selection and CNC programming to final inspection and finishing, we provide complete machining solutions for high-precision internal plastic components.

Send us your drawings or machining requirements today for a free engineering evaluation and custom CNC boring consultation.


FAQ: Boring Service (Precision CNC Internal Turning for Plastic Parts)

When is boring used instead of reaming for precision holes in plastic parts?

Boring is used when the hole diameter is too large for standard reamer sizes, when the hole must be positioned precisely by CNC axis interpolation rather than following a pre-drilled centerline, or when the hole geometry includes a taper, counterbore, or profile that a straight reamer cannot produce.

What bore diameter tolerances are achievable in CNC boring of plastic?

CNC boring on stable engineering plastics can hold bore tolerances of ±0.02–0.05 mm. For bore fits to standard bearing or shaft sizes (H7, H8, etc.), tolerances of ±0.015 mm are achievable with controlled process parameters and temperature-compensated measurement.

How is bore straightness (cylindricity) controlled in CNC boring?

Straightness is controlled by machine spindle geometry, rigid boring bar selection (minimal overhang), and maintaining consistent chip load through the bore depth. We limit boring bar overhang and use vibration-damped bars for deep bores in plastic to maintain cylindricity.

Can boring be used to produce blind bores (non-through holes)?

Yes. CNC boring can produce blind bores to controlled depth with flat or angled bottoms. Chip evacuation is more challenging in blind bores, requiring peck cycles and occasional air blast to clear chips that would otherwise cause re-cutting and surface damage.

What materials are most commonly machined by boring in plastic fabrication?

POM, PEEK, nylon, HDPE, and phenolic laminates are the most common boring materials. These are the engineering plastics most often used for bearing housings, bushings, manifold bores, and precision spacer components where bore accuracy and finish are critical.

Technical Parameters

ParameterTypical Value / Range
Process TypeCNC Boring / Internal Turning
Supported MaterialsPOM, PA (Nylon), PTFE, ABS, PE, PP, Acrylic, PC
Bore Diameter RangeØ5 mm – Ø500 mm
Maximum Machining DepthUp to 1000 mm
Dimensional Tolerance±0.01 mm – ±0.05 mm
Concentricity AccuracyUp to 0.02 mm
Surface RoughnessRa 0.4 – 3.2 μm
Spindle Speed500 – 6000 RPM
Machining AccuracyHigh-Precision CNC Controlled
MOQPrototype to mass production
Secondary ServicesThreading, Grooving, Reaming, Polishing
NoteFinal specifications depend on material properties, bore depth, and component geometry.

Samples