Is this stylus a direct replacement for Renishaw A-5000-3709?

It is dimensionally equivalent: M4 thread, Ø6.0 mm ruby ball, Ø4.5 mm ceramic stem, 50 mm overall length. We confirm the cross-reference against your drawing or part number before shipping. Thread fit and ball diameter are measured and reported per batch.

Does it fit my probe head?

Any probe head with an M4 stylus thread: Renishaw TP20, TP200, TP6, PH10 combinations, ZEISS VAST, Hexagon and Mitutoyo heads using M4 styli, plus most CNC spindle probes with an M4 interface.

What is the ball diameter tolerance?

Grade 10 ruby ball to ISO 3290 as standard, with imported grade 5 balls available on request. Ball diameter, sphericity and straightness are measured on each batch, and the actual values are printed in the shipped ISO/IEC 17025 traceable report — the report value governs, not a catalogue number.

Why ceramic instead of tungsten carbide?

Ceramic has roughly half the density of tungsten carbide at similar stiffness, so a 50 mm ceramic stem deflects less under its own weight and is less likely to be damaged by a crash. Carbide is the better choice when stem diameter must be minimal.

Home / Products / M4 Ø6 ceramic L50

M4 Ø6 mm ceramic stylus — the 50 mm workhorse

M4 thread, Ø6.0 mm ruby ball, Ø4.5 mm ceramic stem, 50 mm overall length. This is the single most-used stylus geometry in CMM and CNC in-process measurement — the one that gets bent, replaced and reordered every quarter.

M4Thread

Ø6.0Ruby ball, mm

Ø4.5Ceramic stem

50Overall length, mm

Cross-reference

Buyers usually arrive here holding an OEM part number. Here is how it maps.

Reference	Value
Our code	BV-M4-50C-06R-3709
OEM reference	A-5000-3709
Thread	M4
Ball diameter	Ø6.0 mm, ruby
Stem	Ø4.5 mm, ceramic
Overall length	50.0 mm
Effective working length	38.5 mm
Ball diameter tolerance	Measured and stated per batch
Sphericity	Measured and stated per batch
Catalogue variants	Ø4.0 / Ø5.0 / Ø6.0 / Ø8.0 ball; 50 / 75 / 100 mm

Cross-references are indicative. Send the part number from your probe head or your last invoice, and we confirm the equivalence in writing within 24 hours — before you commit to a quantity.

M4 thread CMM stylus with Ø6 mm ruby ball and 50 mm ceramic stem

Why this size, and why ceramic

Two engineering facts decide the spec, and both are worth knowing before you substitute anything.

50 mm is the reach compromise

Long enough to clear most fixtures and ribs, short enough that stylus deflection stays inside a few microns. Past 60 mm, bending starts to dominate your measurement uncertainty and the stem material choice stops being optional.

Ceramic resists crashes

Ceramic is stiff but brittle in a predictable way: it fails at the stem instead of transferring the load into the probe head. On a manual machine, that is the difference between a $20 stylus and a probe rebuild.

Ø6 ball suits most surfaces

Big enough to bridge machining marks and small enough to reach into pockets. For roughness-critical surfaces, a larger ball averages the profile; for tight bores, go down to Ø3 or Ø2.

What it fits

Any probe head or spindle probe with an M4 stylus thread. The report travels with the parts, so the receiving inspector has numbers, not claims.

System family	Typical probe heads	Notes
Renishaw	TP20, TP200, TP6, PH10T / PH10M combinations	M4 thread, direct fit
ZEISS	VAST XT / XTR heads using M4 styli	Confirm against your stylus holder
Hexagon / Leitz	M4 interface heads	Direct fit
Mitutoyo	M4 interface CMM heads	Direct fit
CNC spindle probes	M4 interface tool-setting and inspection probes	Check spindle probe stylus length limits

Brand names and part numbers are the property of their respective owners and are used here only to describe compatibility. BEVY styli are not manufactured by, endorsed by, or affiliated with any of these companies.

Questions buyers ask before the first order

How much does it cost?

From USD 18 per piece at sample quantity, dropping with volume. Send the quantity you actually consume per quarter and you get a price for that, not a list price.

Is a calibration report included?

Yes — a batch report covering ball diameter, sphericity, surface roughness, stem straightness and thread fit, traceable to an ISO/IEC 17025 accredited laboratory, at no extra cost. Per-piece certificates are available for USD 8–15 depending on the parameters requested.

What is the lead time?

Stock sizes ship in 3 working days. Quotation within 24 hours, including freight to your door.

Will it measure the same as the OEM stylus?

Take a sample and compare it against the stylus you are using now, on your machine, with your routine. If it falls outside tolerance, do not place the order — we would rather lose the order than your calibration history.

Send the part number. Get the equivalent, priced, tomorrow.

One line in an email is enough: the OEM number, the quantity per quarter, and the country we ship to.

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