Ruby Ball Probe Styli
Our most general purpose probe styli, these Renishaw styli are used with both touch-trigger and scanning probes. When these styli touch your workpiece, they trigger your probe to send a signal and measure geometric features. The ball end is made of ruby, which is second only to diamond in hardness, so it won’t lose its shape or wear over time. It’s completely round and smooth to avoid touching your workpiece at more than one precise point, preventing inaccurate measurements. However, these probe styli don’t work well with aluminum or cast iron surfaces. Aluminum can rub off onto the ruby, and cast iron and ruby are prone to scratching each other during scanning jobs.
As a rule of thumb, you should choose a stylus with the shortest length and largest ball end diameter that works for your application. If a stylus is too long, it’s more likely to move farther than it should, reducing measurement accuracy. Larger ball ends reduce the possibility that the stem will accidentally touch your workpiece and interfere with the reading.
Styli with M4 threads are often used on CNC machine tool probes.
Ceramic stems shatter in a collision instead of bending, minimizing impact to your probe and workpiece.
For technical drawings and 3-D models, click on a part number.

Material | Ball | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
End Dia., mm | Effective Working Lg., mm | O'all Lg., mm | Stem Dia., mm | Stem | Body | End Dia. Tolerance, mm | Grade | Sphericity Tolerance, mm | Manufacturer | Manufacturer Model Number | Each | |
M4 × 0.7 mm | ||||||||||||
6 | 33.4 | 50 | 4.5 | Ceramic | Stainless Steel | -0.00013 to 0.00013 | 5 | -0.00013 to 0.00013 | Renishaw | A-5000-3709 | 000000000 | 000000 |