RS Type Series
RS Type Linear Ball Spline, Cylinder Nut
- Nut Type
- Cylinder (RS)
- Shaft Diameter
- 13 - 32 mm
- Accuracy Grades
- C, H, P
- Dynamic Load Rating
- 4.07 [kN] - 20.5 [kN]
The RS ball spline pairs a cylinder nut with a grooved spline shaft: angular-contact balls guide linear motion and transmit torque through the same interface, which plain linear bushings cannot do. Three ball sets run face-to-face in a retainer-guided cycle for high speed and acceleration, and the encapsulated retainer keeps every ball in the nut when it comes off the shaft. FS flange and FSR rotary nuts ride the identical spline core.
Need rotation and translation on one axis? The FBR compound ball spline stacks a ball-screw nut and a spline nut on a single shaft for linear, rotary and spiral motion. View FBR Type →
-
2x
Rotational stiffness with preload applied
-
181.5 N·m
Dynamic torque rating at Ø32
-
9 µm
P-grade runout, shafts under 200 mm
Applications
- Industrial robot arms
- Automatic loading and unloading machines
- EDM and drilling main shafts
- Stamping die guide shafts
- Measuring instruments and dynamometers
- Winding and packing machines
Sizes
One spline core, three mounts: RS is the plain cylinder nut, FS adds a mounting flange on the same five shaft sizes, and FSR wraps the nut in a rotary outer ring (16 mm and up). Load and torque ratings carry across nut types.
| Model | Shaft Ø (mm) | Dynamic load C (kN) | Dynamic torque CT (N·m) | Configure |
|---|---|---|---|---|
| SP-13-RS | 13 | 4.07 | 5.98 | Configure ↗ |
| SP-16-RS | 16 | 7.2 | 32.1 | Configure ↗ |
| SP-20-RS | 20 | 10.4 | 57.8 | Configure ↗ |
| SP-25-RS | 25 | 15.4 | 106.5 | Configure ↗ |
| SP-32-RS | 32 | 20.5 | 181.5 | Configure ↗ |
Part numbers & options
How a part number reads
SP - 20 - 2 RS - 400 - 500 - C - S
- SP
- Ball spline product family
- 20
- Spline shaft outer diameter (mm) — 13, 16, 20, 25, 32
- 2
- Spline nuts per shaft (blank = 1)
- RS
- Nut type — RS cylinder · FS flange · FSR rotary
- 400
- Length of straight groove (mm)
- 500
- Total shaft length (mm)
- C
- Accuracy — C normal · H high · P precision
- S
- Shaft marking — S solid · blank hollow
The configurator assembles this number for you, with drawings and 3D CAD. Configure ↗
Accuracy grades
Graded by runout of the nut outer diameter against the shaft supports; tolerance scales with shaft length.
- C Normal — General torque-transmission duty
- H High — Repeatable positioning axes
- P Precision — Runout to 9 µm under 200 mm shafts
Clearance & preload
Preload removes rotational clearance; stiffness more than doubles and the effect holds to 2.8x the preload force.
- — No preload — Smooth small-force drives, torsion in one direction
- Light 0 - 0.02C — Cantilever or variable loads, repeat accuracy (robot arms, EDM)
- Medium 0.05C - 0.07C — High stiffness under vibration and moment loads
Shaft execution
- S Solid shaft — Standard
- — Hollow shaft — Weight reduction, air or cable pass-through
Other Ball Splines
How buying works
Spec it in the configurator: drawings, 3D CAD, and a quote to follow.
HIWIN series are configured to your application, not bought off the shelf. Start from your loads and speeds if you are still choosing a size.
Rather talk it through? Request a quote from an application engineer.