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We sell these fine Renishaw probes (and others).

Choosing styli for inspection

By choosing from our comprehensive range of genuine Renishaw styli, you can be sure that the design and materials of your stylus will be optimized.  However, your choice of stylus configuration can have a significant effect on the accuracy of the measurements you take. A few simple rules can be applied to maximize accuracy for most probing applications.


A = ball diameter B = overall length C = stem diameter D = effective working length

Overall length

Renishaw uses a standard description of overall length, measured from the rear mounting face of the stylus to the centre of the ball.

Effective working length (EWL)

This is measured from the centre of the ball to the point at which the stem will foul against the feature when measuring the part.

Rules for choosing a stylus

A few simple rules for stylus selection can be applied to maximize accuracy for most probing applications

Keep styli short

The more the stylus bends or deflects, the lower the accuracy. Probing with the minimum stylus length for your application is the best option.

Minimize joints

Every time you join styli and extensions, you introduce potential bending and deflection points.  Try, wherever possible, to keep to the minimum number of pieces possible for your application.

Keep the stylus ball as large as possible

There are several reasons for this:
  • It maximises your ball/stem clearance, thereby reducing the chance of false triggers caused by 'shanking out' on the stylus stem, and increasing the EWL;
  • A larger ball allows a larger stem diameter, increasing the stiffness of the stylus;
  • The larger ruby ball reduces the effect of the surface finish of the component being inspected.
EWL can also be affected by assembly tolerances. For this reason Renishaw styli are assembled to exacting standards in controlled conditions.

Recommended touch-trigger probes:

TP2 specification

Specification summary TP2-5W
Principal application Universal DCC and manual CMMs.
Sense direction 5-axis: ?X, ?Y, +Z
Unidirection repeatability maximum (2s ?m) (at stylus tip) 0.35 ?m (0.000014 in)
Pre-travel variation 360? (XY plane) ?0.80 ?m (0.000032 in)
Weight  *excluding shank and cable 22 g (0.78 oz)
Stylus force range (adjustable) 0.07 N - 0.15 N
Stylus force (set by Renishaw) 0.07 N - 0.08 N
Stylus overtravel (typical)  XY plane:  ?14?+Z axis:  4 mm (0.16 in) @ 0.07 N
3 mm (0.12 in) @ 0.15 N
Maximum extension on PH10 series 300 mm (11.81 in)
Mounting method M8 thread
Suitable interface PI 4-2, PI 7-2, PI 200, UCC

TP20 specification

Sense directions All modules except 6W 6W ?X, ?Y, +Z?X, ?Y, ?Z
Suitable interface   PI4-2, PI7-2, PI200, UCC
Pre-travel variation LF SF / EM1 / EM2 MF EF 6W ?0.60 ?m (? 0.000023 in) ?0.80 ?m (? 0.000032 in) ?1.00 ?m (? 0.000039 in) ?2.00 ?m (? 0.000079 in) ?1.50 ?m (?0.000058 in)
Unidirectional repeatability  LF / SF / EM1 / EM2 MF EF 6W ?0.35 ?m (? 0.000014 in) ?0.50 ?m (? 0.000020 in) ?0.65 ?m (? 0.000026 in) ?0.80 ?m (? 0.000032 in)
Repeatability of stylus changing MCR20 Manual ?0.50 ?m (? 0.000020 in) ?1.00?m (? 0.000040 in)
Mounting method   M8 thread

TP6(A) specification

Specification summary TP6 TP6A
Principle application Robust universal DCC and manual CMMs. As TP6 but with fast probe exchange without requalification.
Sense directions 5-axis: ?X, ?Y, +Z  5-axis: ?X, ?Y, +Z
Unidirectional repeatability maximum (2s ?m) (at stylus tip) 0.35 ?m (0.000014 in) 0.35 ?m (0.000014 in)
Pre-travel variation 360? (XY plane) ?1 ?m (?0.00004 in) ?1 ?m (?0.00004 in)
Weight 56 g (1.98 oz) 76 g (2.68 oz)
Stylus force range (adjustable) 0.11 N - 0.3 N 0.11 N - 0.3 N
Stylus force (set by Renishaw) 0.11 N - 0.13 N 0.11 N - 0.13 N
Stylus overtravel (typical) XY plane:  ?22?+Z axis:  5.5 mm (0.22 in) @ 0.11 N
2 mm (0.08 in) @ 0.3 N
XY plane:  ?22?+Z axis:  5.5 mm (0.22 in) @ 0.11 N
2 mm (0.08 in) @ 0.3
Maximum extension on PH10 series 200 mm (7.87 in) 200 mm (7.87 in)
Mounting method M8 thread Autojoint
Suitable interface PI 4-2, PI 7-2, PI 200, UCC PI 4-2, PI 7-2, PI 200, UCC
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Stylus terminology