Choosing between two used BHN506 CMM parts comes down to one question first: which subsystem is failing? In dimensional metrology machine inspection, the Mitutoyo 06AAC557 Master Ball and the Yaskawa Minertia UGTMEM-06MMT51 both fit the same Mitutoyo BHN506 coordinate measuring machine, but they serve completely different roles. The master ball is a calibration reference for the probing system. The Yaskawa Minertia is a DC servo motor that controls axis movement. You cannot swap one for the other when the wrong subsystem is down, so the buying decision is really a diagnostic decision.
Quick verdict
Choose the Mitutoyo 06AAC557 Master Ball if your inspection results drift after a stylus or probe change and you need a stable reference for probe qualification. Choose the Yaskawa Minertia UGTMEM-06MMT51 if the CMM's axis travel is sluggish, rough, or unresponsive and you need a replacement motion component. They are complementary spares, not competing alternatives, but your immediate failure mode will point to only one of them.
Comparison at a glance
| Part | Listed price | Job on the BHN506 | Condition / origin |
|---|---|---|---|
| Mitutoyo 06AAC557 Master Ball | USD 1,299.00 | Calibration reference for probe alignment, tip qualification, and error compensation | Used, Japan |
| Yaskawa Minertia UGTMEM-06MMT51 | USD 1,998.00 | High-torque, low-inertia axis drive for positioning and smooth travel | Used, Japan |
Where each product wins
- Mitutoyo 06AAC557 Master Ball wins for calibration dependability. The ball's sphericity and wear-resistant design support repeatable probe-qualification cycles, which matters when you need stable calibration cycles over time.
- Yaskawa Minertia UGTMEM-06MMT51 wins for axis motion. Rapid dynamic response and precise positioning make it the right fit when guide way travel needs to remain controlled.
Product notes
Mitutoyo 06AAC557 Master Ball
If the BHN506's probing system needs a dependable reference after a stylus change, this master ball is the part to use. Its sphericity and wear-resistant construction give you a stable qualification sphere for tip qualification, probing alignment, and error compensation, so you can re-establish repeatable calibration cycles. Choose it when measurement drift has appeared after a probe-related service. The limitation is that it is a calibration artifact, not a drive component; if your CMM's motion is jerky or an axis has lost torque, this ball will not remedy that fault. It is a used part from Japan, so treat it as a reference artifact for your measurement routine, not as a mechanical repair.
Yaskawa Minertia UGTMEM-06MMT51
When the BHN506's guide way travel feels sluggish, rough, or unresponsive, the Yaskawa Minertia UGTMEM-06MMT51 is the component to consider. This is a high-torque, low-inertia DC servo motor designed for rapid dynamic response and precise positioning, which supports smooth, vibration-free movement during close-tolerance inspection routines. Choose it when your problem is axis motion rather than probe calibration. Its limitation is equally specific: it is a motion-system part, not a master ball, so it won't resolve drift caused by probe-tip qualification errors. At $1,998.00, it is the higher-priced part in this comparison, so make sure your diagnosis points to a drive fault before committing.
Final choice by use case
- If you need to re-qualify the probe after a stylus change and restore calibration accuracy, the Mitutoyo 06AAC557 Master Ball is the part to buy.
- If you need to restore reliable axis travel and positioning on the BHN506, the Yaskawa Minertia UGTMEM-06MMT51 is the part to buy.
- If your root cause is probe-related drift but the axis hardware is healthy, the master ball is the correct spare. If the drive motion is the problem, the servo motor is the correct spare. Match the part to the symptom, not to the price.
