When a Mitutoyo BHN506 coordinate measuring machine starts signaling a fault, the replacement decision often comes down to two Japanese-made parts: a pressure switch that guards the air system and a servo motor that powers axis travel. In dimensional metrology machine inspection, a wrong guess means extra downtime, so the useful first step is to match the symptom to the component.
Quick Verdict
If the problem is a pressure-related trip or interlock, the Mitutoyo BHN506 Pressure Switch Sanwa Denki SPS-8T is the lower-priced and more logical first replacement. If the axes are hesitating, drifting, or losing position, the Yaskawa Minertia UGTMEM-06MMT51 is the part that actually drives the CMM and is worth the larger spend.
Listed Price Comparison
| Part | Listed Price | Price Position | Role in the BHN506 |
| Mitutoyo BHN506 Pressure Switch Sanwa Denki SPS-8T | USD 399.00 | | Monitors the pneumatic supply and triggers a fault if pressure drops |
| Yaskawa Minertia UGTMEM-06MMT51 for Mitutoyo BHN506 | USD 1,998.00 | | Axis drive servo motor for CMM movement and positioning |
The table also shows why the two prices make sense: the pressure switch is a small safety sensor, while the servo motor is a substantial drive component. They protect the same CMM at different points in the machine.
Where Each Product Wins
- The pressure switch wins on lower price and first-stage diagnosis. It is the less expensive part and it covers a known failure point without committing to the larger drive component.
- The servo motor wins on motion and positional control. It is the component responsible for axis travel, so it is the answer when the machine physically moves incorrectly.
Product Notes
Mitutoyo BHN506 Pressure Switch Sanwa Denki SPS-8T
At $399, this part is the air-pressure watchdog for the BHN506. It uses a Sanwa Denki SPS-8T adjustable switch to monitor the compressed air that feeds the CMM's air bearings and pneumatic counterbalance. If pressure falls below the operating threshold, it triggers a fault or interlock signal, protecting the guideways and axes from damage. It is the right replacement when the symptom points to the pneumatic system, such as a fault that appears with low air supply. Its limitation is scope: it only guards pressure. If the axis motor itself is weak or failing, this switch will not improve movement. It is also a used component made in Japan, so it is best treated as a targeted replacement for a known air-supply fault rather than a universal fix.
Yaskawa Minertia UGTMEM-06MMT51 for Mitutoyo BHN506
At $1,998, this is the higher-priced component of the pair. It is a Yaskawa Minertia UGTMEM-06MMT51 DC servo motor built for the BHN506, with low inertia and high torque for rapid response and precise positioning. The motor drives the axes along the CMM guideways, so if the machine hesitates, drifts, or loses repeatability, this part is the one doing that work. It earns its price when the fault is clearly in axis motion rather than a low-supply issue. Its downside is the opposite of the switch's scope: it cannot diagnose or protect against low air supply, and its used condition means you are paying for a substantial electromechanical component rather than a small sensor.
Final Choice by Use Case
- If you see a pressure-related fault or interlock trip: start with the Mitutoyo BHN506 Pressure Switch Sanwa Denki SPS-8T before spending on anything larger.
- If you have sluggish or inaccurate axis movement: the Yaskawa Minertia UGTMEM-06MMT51 addresses the drive itself.
- If you are not sure which side failed: the lower-priced pressure switch protects the air-bearing system and is the sensible first step; if the machine still moves incorrectly after that, the servo motor becomes the target.
