Probe Styli & Accessories for CNC Measurement

Probe styli and accessories connect the measuring system to the workpiece, enabling contact measurement, workpiece alignment, and in-machine inspection. QIDU provides probe styli, stylus extensions, and probe shanks for CNC applications. Selecting the correct ball geometry, tip material, stem construction, dimensions, and thread interface helps ensure suitable feature access, mechanical compatibility, and stable probing performance.
Contact geometry
Ball/fiat/specialized
Mechanical fit
Thread /length / mass
Technical support
Configuration review
01 By application
02 Stylus geometries
03 Dimensions
04 Compatibility
05 Products & RFQ

Which Probe Stylus Is Right for Your Measurement Application

A probe stylus is the contact component attached to a measuring probe—not the complete sensor assembly. The correct design depends on workpiece geometry, probing direction, available clearance, and the measurement system.
Workpiece datum setting
Straight ball stylus for accessible reference surfaces
CNC feature measurement
Ball geometry suited to bores, bosses, slots, and edges
Hole and bore inspection
Contact ball size and working length matched to internal clearance
Deep or restricted features
Longer or stepped configurations, subject to probe limits
CMM dimensional inspection
Application-specific CMM styli; special shapes where supported

Probe Stylus Types: Straight, Star, Disc & Specialized Designs

Different stylus geometries provide different contact directions and access capabilities

Straight ball
General CNC probing, surfaces, holes, and datum setting
Star styli
Multi-directional access and complex CMM features
Disc styli
Grooves, undercuts, and internal features
Flat contact tips
Suitable planar contact applications
Stepped or specialized
Recessed features and restricted access
Straight ball designs are a practical starting point for many CNC touch-trigger applications. Star and disc designs are established industrial metrology options, but their suitability depends on the particular probe and measurement method.

How Do Ball Diameter, Stylus Length & Working Length Affect Selection

Probe Styli & Accessories

A Ball diameter

B Overall length

C Stem diameter

D Effective working length

Stylus dimensions determine whether the contact element can reach the intended surface without interference. They also influence stiffness, deflection, and allowable probe operation
Match ball size to the smallest accessible feature.
Check overall length against the product drawing.
Verify effective working length for the actual geometry.
Consider stem stiffness, assembly mass and extra joints.
Use the shortest practical configuration that provides access.
Engineering considerations：Overall length and effective working length are not interchangeable. A stepped shaft may provide improved rigidity while reducing the usable measuring reach.

Longer assemblies and additional joints can increase deflection or compromise measurement stability. Select the shortest practical configuration that provides sufficient access.

Ruby, Silicon Nitride & Other Stylus Tip Materials

The contact-tip material influences wear, surface interaction, and suitability for different workpieces.
Ruby
General CNC probing, surfaces, holes, and datum setting
Silicon nitride
Multi-directional access and complex CMM features
Zirconia
Grooves, undercuts, and internal features
Tungsten carbide
Suitable planar contact applications

Steel, Tungsten Carbide, Ceramic & Carbon Fiber Stylus Stems

The stem supports the contact element and influences assembly stiffness, weight, deflection, and thermal behavior.
Stainless steel
Durable and practical for suitable shorter assemblies
Tungsten carbide
High stiffness for its dimensions
Ceramic
Relatively lightweight and stiff in suitable geometries
Carbon fiber
Low mass and potentially favorable thermal stability
M2, M3, M4 & M5 Stylus Threads
M2, M3, M4 & M5 Stylus Threads
M2, M3, M4 & M5 Stylus Threads
M2, M3, M4 & M5 Stylus Threads

M2, M3, M4 & M5 Stylus Threads: How Do You Check Compatibility

Stylus threads establish the mechanical connection between the stylus and the probe or an intermediate adapter
A matching thread establishes only part of mechanical compatibility. It does not guarantee suitable probing forces, measurement performance, or controller integration.
Probe manufacturer and exact model.
Existing stylus thread designation and connection details.
Ball size, length, geometry, and total assembly mass.
Required measuring directions and operating clearance.
Whether an adapter is needed and permitted.

Stylus Extensions, Adapters & Probe Shanks

Accessories allow a measurement assembly to accommodate different working distances, connections, and CNC spindle interfaces

01

Stylus Extensions
Increase reach for deep or difficult-to-access features.
Verify: length, mass, rigidity, joints and clearance

02

Thread Adapters
Connect different compatible stylus-thread interfaces.
Verify: both thread specifications and engagement

03

Connection Accessories
Secure or position supported stylus assemblies.
Verify: matching interface, alignment and stability

04

Probe Shanks
Connect the CNC probe body to the machine spindle.
Verify: taper, mounting interface, gauge length and retention
Stylus Extensions
Stylus Extensions
Explore extension configurations for compatible probe
assemblies.
Probe Shanks

Probe Shanks

Review compatible CNC spindle mounting interfaces.

How to Choose a Probe Styli Supplier & Request the Right Configuration

Selecting a supplier requires more than finding a matching thread or visually similar replacement part.

Buyers should compare published product dimensions, available material options, mechanical compatibility information, product identification, and technical documentation. Inspection records or customization requirements should be discussed before purchase where necessary.

For replacement matching or new installations, provide the following information.

Stylus Quotation Checklist:
Probe information: Manufacturer, model, and existing part number.
Contact element: Required ball diameter, tip geometry, and material.
Typical cutter types and minimum/maximum diameters
Required measurements, breakage checks, or monitoring functions
Dimensions: Overall length, effective working length, and stem diameter.
Construction: Preferred stem material and assembly arrangement.
Application: Workpiece material, feature geometry, probing direction, and machine environment.
Purchasing details: Quantity, delivery destination, and documentation requirements.
For assemblies involving different probe brands, additional mechanical and operating information may be necessary.

Explore QIDU Probe Styli & Accessories

Browse QIDU’s available probe styli, extensions, and accessories. Review individual product specifications, compare configurations, and identify suitable components for your application.

Probe Styli & Accessories Guides & Resources

Explore additional technical guidance on stylus selection, thread compatibility, contact materials, CNC probe installation, and practical measurement applications.