Find your Torque Value
Pick your part below and the finder returns the exact figure, the screw size and the number of screws.
The figure is a maximum per screw and a reference value, not a target worked back from a required preload. Oil the threads first and set it with a torque wrench, keeping at or below the number.
Pick a series and size, or type your part number above.
Torque and Force Calculation Formula
T = F × K(N·m)
K = ½ × { dp × tan(ρ′ + β) + dw × μw } × 10−3(m)
ρ′ = tan−1 μs
β = tan−1(pitch3.142 × dp)
dw =D + d2(mm)
μw = μs ≈ 0.15
- T
- Nut locking torque
- F
- Nut tightening force
- dp
- Nut effective diameter (mm)
- ρ′
- Thread friction angle
- β
- Nut lead angle
- μs
- Coefficient of friction for the thread
- μw
- Coefficient of friction for the nut connecting face
- dw
- Average diameter of friction torque for the nut connecting face (mm)
Questions About Locknut Torque
Every NIKKI locknut has a rated tightening torque for its screws, fixed by the screw size and running from 0.9 to 100 Nm. The figures are catalogue reference values, set with a torque wrench onto oiled threads, and each is a maximum rather than a target worked back from a required preload. The questions here are the ones that come up when setting them.
Contact UsUse the maximum for the screw size on your part, and no more. Each screw size has one rated figure: M3 0.9 Nm, M4 2.2 Nm, M5 4.8 Nm, M6 8 Nm, M8 19 Nm, M10 36 Nm, M12 60 Nm, and M14 100 Nm.
The axial MA sizes and the single MRRA150/230 are the exception: their M12 screw is rated to 56 Nm rather than 60. The finder reads each size from its own catalogue row, so it applies that for you.
Per screw. A NIKKI nut carries three, four, six or eight screws depending on the size, and each one takes the rated torque. The finder shows the screw count next to the figure so you can see what the part needs.
Clean and dry the shaft and nut, oil the threads, then tighten the screws to the rated figure with a torque wrench. Oiling is part of the method, because tightening torque and the clamp force it produces are linked through friction, which is what the test in ISO 16047 measures. That is why NIKKI publishes these as reference figures rather than exact settings, and why a dry or dirty thread changes the result.
No. NIKKI publishes a rated maximum per screw, not a torque derived from a target preload, so neither the finder nor this page converts a required axial force into a screw torque. If you need that, send the load, thread size and application to NIKKI through an RFQ and their engineers will advise.
