
PMI's precision ground Ballscrews are controlled in accordance with JIS B 1192.
The permissible values and each part of defi nitions are shown below.
Technical Terms Concerning the Lead

Terms
T+E |
Cumulative representative lead.
A straight line representing the tendency of the cumulative actual lead. This is obtained by least square method and measured by laser system. |
P |
Permissible value.
|
a |
Actual value.
|
T |
Specifi ed travel.
This value is determined by customer and maker as it depends on different application requirements. |
E |
Accumulated reference lead deviation.
This is allowable deviation of specified travel. It is decided by both of the accuracy grade and effective thread length. |
e |
Total relative lead variation
Maximum width of variation over the travel length. |
e300 |
Lead deviation in random 300 mm.
|
e2π | Lead deviation in random 1 revolution 2π rad. |
Accumulated reference lead deviation (±E) and total relative variation (e)
Unit:μm
Effective thread length (mm) | GRADE | Co | C1 | C2 | C3 | C4 | C5 | |||||||
OVER | UP TO | E | e | E | e | E | e | E | e | E | e | E | e | |
315 | 4 | 3.5 | 6 | 5 | 8 | 7 | 12 | 8 | 12 | 12 | 23 | 18 | ||
315 | 400 | 5 | 3.5 | 7 | 5 | 9 | 7 | 13 | 10 | 14 | 12 | 25 | 20 | |
400 | 500 | 6 | 4 | 8 | 5 | 10 | 7 | 15 | 10 | 16 | 12 | 27 | 20 | |
500 | 630 | 6 | 4 | 9 | 6 | 11 | 8 | 16 | 12 | 18 | 14 | 30 | 23 | |
630 | 800 | 7 | 5 | 10 | 7 | 13 | 9 | 18 | 13 | 20 | 14 | 35 | 25 | |
800 | 1000 | 8 | 6 | 11 | 8 | 15 | 10 | 21 | 15 | 22 | 16 | 40 | 27 | |
1000 | 1250 | 9 | 6 | 13 | 9 | 18 | 11 | 24 | 16 | 25 | 18 | 46 | 30 | |
1250 | 1600 | 11 | 7 | 15 | 10 | 21 | 13 | 29 | 18 | 29 | 20 | 54 | 35 | |
1600 | 2000 | 18 | 11 | 25 | 15 | 35 | 21 | 35 | 22 | 65 | 40 | |||
2000 | 2500 | 22 | 13 | 30 | 18 | 41 | 24 | 41 | 25 | 77 | 46 | |||
2500 | 3150 | 26 | 15 | 36 | 21 | 50 | 29 | 50 | 29 | 93 | 54 | |||
3150 | 4000 | 32 | 18 | 44 | 25 | 60 | 35 | 62 | 35 | 115 | 65 | |||
4000 | 5000 | 52 | 30 | 72 | 41 | 76 | 41 | 140 | 77 | |||||
5000 | 6300 | 65 | 36 | 90 | 50 | 95 | 50 | 170 | 93 | |||||
6300 | 8000 | 110 | 62 | 120 | 62 | 210 | 115 | |||||||
8000 | 10000 | 157 | 75 | 260 | 140 |
Variation in random 300mm (e300) and wobble (e2π)
e300 | Unit:μm |
CRADE | Co | C1 | C2 | C3 | C4 | C5 | C6 | C7 | C10 |
JIS | 3.5 | 5 | 8 | 18 | 50 | 210 | |||
PMI | 3.5 | 5 | 7 | 8 | 12 | 18 | 25 | 50 | 210 |
e2π | Unit:μm |
CRADE |
Co |
C1 | C2 | C3 | C4 | C5 |
JIS | 3 | 4 | 6 | 8 | ||
PMI | 3 | 4 | 4 | 6 | 8 | 8 |