Precision Locknut PSK Series
PMK Precision Locknuts – PSK Series are high‑accuracy clamping nuts designed for secure axial locking of bearings, spindle shafts, and rotating components in precision machinery.
These locknuts are manufactured to fine tolerances and incorporate multiple radial clamping screws for uniform preload distribution, high concentricity, and vibration resistance. The PSK design enables precise bearing positioning with minimal runout, ideal for spindles, ball screws, and rotary tables requiring consistent torque and stability.
Key benefits
- Performance: supports secure and repeatable axial clamping across thread sizes M40 × 1.5 to M300 × 4.0.
- Precision: ground face and thread geometry ensure accurate bearing preload and high axial accuracy.
- Reliability: multiple clamping screws provide uniform locking pressure and superior resistance to loosening under vibration.
- Versatility: wide size range suitable for machine tools, spindles, ball screws, and rotary assemblies.
- Serviceability: reusable, low‑maintenance design with torque values matched to thread pitch and application load.
Applications
- Spindle and bearing assemblies in CNC and precision machine tools.
- Ball screw end‑supports and rotary table locking systems.
- Automation, robotics, and indexing mechanisms.
- General‑purpose mechanical assemblies requiring rigid axial retention.
Specifications
| Type × Pitch | D | h | d | c | n × Øb | n‑M × L | Torque (Nm) |
|---|---|---|---|---|---|---|---|
| PSK M 10 x 0.75 | 24 | 14 | 22 | 17 | 3 x Ø2.5 | 3 - M3 x 10 | 1 |
| PSK M 10 x 1.0 | 24 | 15 | 22 | 17 | 3 x Ø2.5 | 3 - M3 x 10 | 1 |
| PSK M 12 x 1.0 | 26 | 14 | 25 | 19 | 3 x Ø3 | 3 - M3 x 10 | 1 |
| PSK M 12 x 1.5 | 26 | 15 | 25 | 19 | 3 x Ø3 | 3 - M3 x 10 | 1 |
| PSK M 14 x 1.5 | 32 | 16 | 30 | 19 | 3 x Ø4 | 3 - M3 x 10 | 1 |
| PSK M 15 x 1.0 | 33 | 16 | 31 | 22.5 | 3 x Ø4 | 3 - M3 x 10 | 1 |
| PSK M 16 x 1.5 | 34 | 18 | 30 | 25 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 17 x 1.0 | 37 | 18 | 32 | 26 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 18 x 1.5 | 38 | 18 | 33 | 28 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 20 x 1.0 | 40 | 18 | 35 | 30 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 20 x 1.5 | 40 | 18 | 36 | 30 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 22 x 1.5 | 42 | 18 | 37 | 32 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 24 x 1.5 | 44 | 18 | 39 | 34 | 4 x Ø4 | 4 - M4 x 12 | 3.5 |
| PSK M 25 x 1.5 | 45 | 20 | 40 | 35 | 4 x Ø5 | 4 - M4 x 12 | 3.5 |
| PSK M 26 x 1.5 | 45 | 20 | 40 | 35 | 4 x Ø5 | 4 - M4 x 12 | 3.5 |
| PSK M 27 x 1.5 | 46 | 20 | 43 | 37 | 4 x Ø5 | 4 - M4 x 12 | 3.5 |
| PSK M 28 x 1.5 | 46 | 20 | 43 | 37 | 4 x Ø5 | 4 - M4 x 12 | 3.5 |
| PSK M 30 x 1.5 | 48 | 20 | 48 | 39 | 4 x Ø5 | 4 - M4 x 12 | 3.5 |
| PSK M 32 x 1.5 | 50 | 22 | 47 | 41 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 33 x 1.5 | 51 | 22 | 48 | 42 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 35 x 1.5 | 53 | 22 | 50 | 44 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 38 x 1.5 | 56 | 22 | 53 | 47 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 39 x 1.5 | 58 | 22 | 55 | 47 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 40 x 1.5 | 58 | 22 | 55 | 49 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 42 x 1.5 | 60 | 22 | 57 | 51 | 4 x Ø5 | 4 - M4 x 16 | 3.5 |
| PSK M 45 x 1.5 | 68 | 25 | 63 | 57 | 6 x Ø6 | 6 - M4 x 18 | 3.5 |
| PSK M 48 x 1.5 | 69 | 25 | 65 | 58 | 6 x Ø6 | 6 - M4 x 18 | 3.5 |
| PSK M 50 x 1.5 | 70 | 25 | 66 | 60 | 6 x Ø6 | 6 - M4 x 18 | 3.5 |
| PSK M 52 x 1.5 | 72 | 25 | 68 | 62 | 6 x Ø6 | 6 - M4 x 18 | 3.5 |
| PSK M 55 x 1.5 | 75 | 25 | 71 | 65 | 6 x Ø6 | 6 - M4 x 18 | 3.5 |
| PSK M 55 x 2.0 | 75 | 25 | 71 | 65 | 6 x Ø6 | 6 - M4 x 18 | 4.5 |
| PSK M 56 x 1.5 | 75 | 26 | 71 | 65 | 6 x Ø6 | 6 - M4 x 18 | 4.5 |
| PSK M 58 x 1.5 | 82 | 26 | 77 | 70 | 6 x Ø6 | 6 - M5 x 20 | 4.5 |
| PSK M 60 x 1.5 | 84 | 26 | 79 | 72 | 6 x Ø6 | 6 - M5 x 20 | 4.5 |
| PSK M 60 x 2.0 | 84 | 26 | 79 | 72 | 6 x Ø6 | 6 - M5 x 20 | 4.5 |
| PSK M 62 x 1.5 | 86 | 28 | 82 | 75 | 6 x Ø6 | 6 - M5 x 20 | 4.5 |
| PSK M 64 x 1.5 | 86 | 28 | 82 | 75 | 6 x Ø6 | 6 - M5 x 20 | 4.5 |
| PSK M 65 x 2.0 | 88 | 28 | 88 | 77 | 6 x Ø6 | 6 - M5 x 20 | 4.5 |
| PSK M 68 x 1.5 | 93 | 28 | 87 | 80 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 68 x 2.0 | 93 | 28 | 87 | 80 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 70 x 1.5 | 95 | 28 | 89 | 82 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 70 x 2.0 | 95 | 28 | 89 | 82 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 72 x 1.5 | 97 | 28 | 91 | 84 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 75 x 1.5 | 100 | 28 | 94 | 87 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 75 x 2.0 | 100 | 28 | 94 | 87 | 6 x Ø7 | 6 - M5 x 20 | 4.5 |
| PSK M 80 x 2.0 | 110 | 32 | 103 | 95 | 6 x Ø8 | 6 - M6 x 22 | 4.5 |
| PSK M 85 x 2.0 | 115 | 32 | 108 | 100 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 90 x 2.0 | 120 | 32 | 113 | 105 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 95 x 2.0 | 125 | 32 | 118 | 110 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 100 x 2.0 | 130 | 32 | 123 | 115 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 105 x 2.0 | 135 | 32 | 128 | 120 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 110 x 2.0 | 140 | 32 | 133 | 125 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 115 x 2.0 | 145 | 34 | 137 | 130 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 116 x 2.0 | 145 | 34 | 137 | 130 | 6 x Ø8 | 6 - M6 x 22 | 8 |
| PSK M 120 x 2.0 | 155 | 36 | 146 | 136 | 6 x Ø8 | 6 - M6 x 25 | 8 |
| PSK M 125 x 2.0 | 160 | 36 | 150 | 140 | 6 x Ø8 | 6 - M6 x 25 | 8 |
| PSK M 130 x 2.0 | 165 | 36 | 155 | 148 | 6 x Ø8 | 6 - M6 x 25 | 8 |
| PSK M 130 x 3.0 | 165 | 36 | 155 | 148 | 6 x Ø8 | 6 - M6 x 25 | 8 |
| PSK M 140 x 2.0 | 180 | 38 | 168 | 160 | 8 x Ø10 | 8 - M6 x 25 | 8 |
| PSK M 140 x 3.0 | 180 | 38 | 168 | 160 | 8 x Ø10 | 8 - M6 x 25 | 8 |
| PSK M 150 x 2.0 | 190 | 38 | 178 | 170 | 8 x Ø10 | 8 - M6 x 25 | 8 |
| PSK M 150 x 3.0 | 190 | 38 | 178 | 170 | 8 x Ø10 | 8 - M6 x 25 | 8 |
| PSK M 160 x 3.0 | 205 | 40 | 190 | 178 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 170 x 3.0 | 215 | 40 | 203 | 193 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 180 x 3.0 | 230 | 40 | 215 | 205 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 190 x 3.0 | 240 | 40 | 225 | 215 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 200 x 3.0 | 245 | 40 | 233 | 223 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 210 x 4.0 | 265 | 40 | 253 | 243 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 220 x 3.0 | 265 | 40 | 253 | 243 | 8 x Ø10 | 8 - M8 x 30 | 18 |
| PSK M 220 x 4.0 | 265 | 40 | 253 | 243 | 8 x Ø10 | 8 - M10 x 30 | 35 |
| PSK M 240 x 3.0 | 285 | 42 | 275 | 263 | 8 x Ø12 | 8 - M10 x 30 | 35 |
| PSK M 260 x 3.0 | 305 | 42 | 295 | 283 | 8 x Ø12 | 8 - M10 x 30 | 35 |
| PSK M 260 x 4.0 | 305 | 42 | 295 | 283 | 8 x Ø12 | 8 - M10 x 30 | 35 |
| PSK M 280 x 4.0 | 325 | 42 | 315 | 303 | 8 x Ø12 | 8 - M10 x 30 | 35 |
| PSK M 300 x 4.0 | 345 | 42 | 335 | 323 | 8 x Ø12 | 8 - M10 x 30 | 35 |
* Specifications subject to change. Contact us for the latest datasheet and custom configurations.
* Refer Disclaimer policy for more details.
