Page 9 of catalogue Precision rail guides of SKF Linearsysteme GmbH

Technical data
Precision of rail guides All SKF precision rail guides, regardless of type, are manufactured to the same tolerances indicated below. Raceway accuracy In order to meet the different requirements regarding the precision of linear bearing arrangements, the rails are produced in three different tolerance classes. These are classified according to the parallelism between the raceways and the support surfaces A and B (Fig. 6). P10 Tolerance class normal. This meets the requirements of general engineering applications. The deviation from parallelism for a 1 000 mm long rail is approximately 10 μm. See also adjacent table 1. P5 This satisfies the demands normally made on the running accuracy for machine tool applications. The deviation from parallelism for a 1 000 mm long rail is 5 μm maximum. See also adjacent table 1. P2 Accuracy for the most exacting demands. Rails made to this tolerance class should only be used when the associated Components are made to a correspondingly high degree of precision. Rails to tolerance class P2 will be manufactured by SKF to special order. See also table 1. If no mention is made of the requisite accuracy on the order, rails with normal P10 tolerances will be supplied.
Table 1 Permissible deviation in parallelism between reference planes A and B Rail length from Tolerance class P10 P5
mm

Dimensional accuracy SKF precision rail guides with limited travel are produced to the following tolerances (Figs. 7 and 8):
Width A: 0/-0,3mm Abutment height T = B1 + B2 ± 0,02 mm Rail height B: 0/-0,2 mm Rail length L: L ≤ 300 ± 0,3 L > 300 ± 0,001 · L [mm]

For rails composed of two or more sections the tolerance for the total length is ± 2 mm. SKF precision rail guides for recirculating roller assemblies are produced to the following tolerances: Width A: 0/+0,1 mm Height A: 0/+0,1 mm Length L: L ≤ 300 ± 0,3 L > 300 ± 0,001 · L [mm]

Fig. 6

to
mm

P2

100 200 300 400 500 600 700 800 900 1 000 1 200 1 400

100 200 300 400 500 600 700 800 900 1 000 1 200 1 400 1 600*

2 3 4 5 6 6 7 8 8 9 10 11 12

1 2 2 2 3 3 4 4 5 5 6 6 7

1 1 1 2 2 2 2 2 2 2 3 3 3

* Rail length > 1 600 mm, please contact SKF

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