STAR – Precision Ball Screw Assemblies

Symbol definitions
(excerpt):
l0 = nominal travel
l1 ∆l0 lu le c
=
=
=
=
=
thread length
travel deviation
useful travel
excess travel
travel compensation for useful
travel, defined by use
(standard: c = 0)
ep = tolerance for actual mean
travel deviation
νup = permissible travel variation
within useful travel lu ν300p = permissible travel deviation
within 300 mm travel
ν2πp = permissible travel deviation
within 1 revolution
Subindices:
p = permissible
a = actual
Improved values
Values are more accurate than those
defined in DIN 69 051, Part 3 and
ISO 3408-3 (tolerance reduced by half).
Minimum number of measurements within
300 mm (measuring interval) and permissible
excess travel.
ep (µm)
Tolerance grade
1 3 5 7 9
RE 83 301/12.99 81
T
T
Ball screw with ground-thread or rolled precision screw
l e
+
0
∆l
-
lu
e p´ 300
ν
300p
l 1
l u
300
ν 300p
l e
e p
e p
l 0
c = 0
Lead Min. no. measurements for tolerance grades l emax
1 3 5 7 9 (mm)
2.5 30 20 10 5 5 10
5 15 10 6 3 3 20
10 10 5 3 1 1 40
16 8 5 3 1 1 50
20 5 5 3 1 1 60
25 4 4 3 1 1 70
32 3 3 2 1 1 80
40 - 2 1 1 1 100