General Geometric Tolerances (Acceptance Criteria)

The values listed below represent general rules for run-out tolerances of ball screws. For specific applications tolerances may vary.

Steinmeyer recommends supporting the screw using the outside diameter for all inspection of geometric tolerances. This will ensure optimum repeatability of measurement. In some cases the center holes are used as reference.

  Journal run-out t2 [µm]
Accuracy class
Nominal
diameter
dN [mm]
P0 P1 P2 P3 P4 P5 T7 T10
3 - 6 5 7 7 8 10 - - -
8 - 10 5 7 7 9 10 10 20 -
12 5 7 8 9 10 10 20 -
16 - 20 5 7 9 10 12 13 20 -
25 - 32 6 8 10 11 12 14 25 -
36 - 50 7 9 12 13 15 16 25 -
60 - 125 8 10 13 14 16 18 25 -

  Run-out t3 [µm]
Accuracy class
Nominal
diameter
dN [mm]
P0 P1 P2 P3 P4 P5 T7 T10
3 - 6 3 4 6 7 8 10 - -
8 - 10 4 5 7 8 9 11 12 15
12 4 5 7 8 9 11 13 17
16 - 20 4 6 8 9 10 12 15 18
25 - 32 5 7 9 10 12 13 16 19
36 - 50 6 8 11 12 14 15 18 21
60 - 125 7 9 12 13 15 17 20 23
  Perpendicularity t4 [µm]
Accuracy class
Nominal
diameter
dN [mm]
P0 P1 P2 P3 P4 P5 T7 T10
3 - 6 2 2 2 3 3 3 - -
8 - 10 2 2 2 3 3 4 5 7
12 2 2 2 3 3 4 6 8
16 - 20 2 3 3 4 4 5 7 9
25 - 32 2 3 4 4 4 5 7 9
36 - 50 2 3 4 4 4 5 7 9
60 - 125 3 4 5 5 6 7 10 13
  Perpendicularity t5 [µm]
Accuracy class
Nominal
diameter
dN [mm]
P0 P1 P2 P3 P4 P5 T7 T10
3 - 6 6 7 8 9 9 10 - -
8 - 10 6 7 8 9 9 10 15 -
12 6 7 8 9 9 10 20 -
16 - 20 7 8 9 10 10 12 25 -
25 - 32 7 8 9 10 10 12 32 -
36 - 50 8 9 10 10 12 13 32 -
60 - 125 9 10 11 12 13 15 40 -
  Run-out of pilot diameter  t6 [µm]
Accuracy class
Nominal
diameter
dN [mm]
P0 P1 P2 P3 P4 P5 T7 T10
3 - 6 5 6 7 8 9 10 - -
8 - 10 5 6 7 8 9 10 20 -
12 5 6 7 8 9 10 20 -
16 - 20 5 6 7 8 9 10 20 -
25 - 32 5 6 7 8 9 10 20 -
36 - 50 6 7 8 8 10 11 25 -
60 - 125 7 8 9 10 12 13 32 -

Technical Tip: 

Steinmeyer recommends supporting the screw by using V-blocks for all inspection of geometric tolerances. This will ensure optimum repeatability of the measurement. If necessary, dual gages can be used to measure the concentricity of two surfaces with respect to one another, e.g. the concentricity of drive journal and bearing journal. This measuring method includes the perpendicularity and run-out tolerance of the nut already.

© 2013 August Steinmeyer GmbH & Co. KG