Specs/CAD
| Part Number | Max. Bore Diameter (mm) |
Rated Torque*1 (N・m) | |||||||
|---|---|---|---|---|---|---|---|---|---|
| MSTS-32K | 14 | 3.5 | 19000 | 2.6×10-5 | 850 | 0.15 | 2 | ±0.5 | 160 |
| MSTS-40K | 18 | 8 | 15000 | 8.6×10-5 | 1000 | 0.2 | 2 | ±0.5 | 340 |
| MSTS-50K | 20 | 15 | 12000 | 2.8×10-4 | 1400 | 0.2 | 2 | ±0.5 | 730 |
| MSTS-63K | 30 | 35 | 10000 | 8.5×10-4 | 1800 | 0.2 | 2 | ±0.5 | 1300 |
*1: Correction of rated torque due to load fluctuation is not required. For more detailed information, please refer to Selection Guidelines.
*2: These are values with max. bore diameter.
| Part Number | Standard Bore Diameter (Dimensional Allowance H8) D1・D2 |
||||
|---|---|---|---|---|---|
| MSTS-32K | 12-12 | 14-14 | |||
| MSTS-40K | 14-14 | 16-16 | 18-18 | ||
| MSTS-50K | 16-16 | 18-18 | 20-20 | ||
| MSTS-63K | 20-20 | 25-25 | |||
●All products are provided with hex socket set screws.
●Recommended tolerance for shaft diameters is h6 and h7.
●Bore modifications are available on request. Please take advantage of our modification services.
●For the shaft insertion amount to the coupling, see Mounting/maintenance. ⇒Mounting and Maintenance
Details of Shaft Hole

Unit : mm
| Standard Bore Diameter D |
Keyway | Key | |||
|---|---|---|---|---|---|
| b | t | Nominal Dimension b x h |
|||
| Standard Dimension | Allowance (JS9) |
Standard Dimension | Allowance | ||
| 12 | 4 | ±0.0150 | 1.8 | 0 - +0.1 | 4 × 4 |
| 14 · 16 | 5 | ±0.0150 | 2.3 | 0 - +0.1 | 5 × 5 |
| 18 · 20 | 6 | ±0.0150 | 2.8 | 0 - +0.1 | 6 × 6 |
| 25 · 30 | 8 | ±0.0180 | 3.3 | 0 - +0.2 | 8 × 7 |
Structure
MSTS-KMade of all stainless steel
Set Screws + Key TypeMST-KMSTS-K
MST-KMade of aluminum alloy
Outside diameter φ12 - φ32

Clamping TypeMST-CMSTS-C
MST-C Made of aluminum alloyMSTS-C Made of all stainless steel
Outside diameter φ40 - φ63

Set Screw TypeMSTMSTS
MST Made of aluminum alloyMSTS Made of all stainless steel

Material/Finish
| MSTS-K | |
|---|---|
| Main Body | SUS303 |
| Hex Socket Set Screw | SUSXM7 |
| Hex Socket Head Cap Screw | SUSXM7 |
Characteristics
- This is a metal spring coupling with single-piece construction. A slit is inserted into a cylindrical material.
- A plate spring formed by a slit allows eccentricity, angular misalignment, and end-play to be accepted.
- There are two types of units made of aluminum alloy or all stainless steel.
- Wide variation of outside diameter φ 8 - φ 63.
- Property
| MST | MSTS | |
|---|---|---|
| Zero Backlash | ◎ | ◎ |
| High Torque | ○ | ○ |
| High Torsional Stiffness | ○ | ○ |
| Allowable Misalignment | ○ | ○ |
| Corrosion Resistance (All S.S.) | - | ◎ |
- Applicable motors
| MST | MSTS | |
|---|---|---|
| Servomotor | ● | ● |
| Stepping Motor | ◎ | ◎ |
| General-purpose Motor | ● | ● |
Application
Transport device / XY stage / Parts feederSelection
Selection Example
In case of selected parameters of shaft diameter of φ10 and load torque of 1.5 N•m, the selected size forMSTMSTSis MST-25MSTS-25



Selection Based on Shaft Diameter and Rated Torque
The area bounded by the shaft diameter and rated torque indicates the selection size.Eccentric Reaction Force


Thrust reaction force


Change in static torsional stiffness due to temperature

The change of MST and MSTS in torsional stiffness due to temperature is small and the change in responsiveness is extremely small. If the unit is used under higher temperature, be careful about misalignment due to elongation or deflection of the shaft associated with thermal expansion.







