Page 153 - Rollingbearings

Seat tolerances for standard conditions
Table 8
Tolerances for cast iron and steel housings – seats for radial bearings 1)

Conditions Dimensional Total radial run-out Total axial run-out Ra 6) Displacement of
tolerance 2)3) tolerance tolerance outer ring
– – – µm –

For non-split Rotating outer ring load
housings only
Heavy loads on bearings in P7 IT6/2 IT6 3,2 Cannot be
thin-walled housings, displaced
heavy peak loads (P > 0,1 C)
Normal to heavy loads N7 IT6/2 IT6 3,2 Cannot be
(P > 0,05 C) displaced

Light and variable loads M7 IT6/2 IT6 3,2 Cannot be
(P ≤ 0,05 C) displaced

Direction of load indeterminate
Heavy peak loads M7 IT6/2 IT6 3,2 Cannot be
displaced
Normal to heavy loads K7 5) IT6/2 IT6 3,2 In most cases,
(P > 0,05 C), axial displace- cannot be
ment of outer ring displaced
unnecessary

For non-split Direction of load indeterminate
housings and split
housings
Light to normal loads J7 IT6/2 IT6 3,2 In most cases, can
(P ≤ 0,1 C), axial displace- be displaced
ment of outer ring desirable Bearing interfaces

Stationary outer ring load

Loads of all kinds H7 3) IT6/2 IT6 3,2 Can be displaced B.6
Light to normal loads H8 3) IT6/2 IT6 3,2 Can be displaced
(P ≤ 0,1 C) with simple work-
ing conditions
Thermal expansion of the G7 4) IT6/2 IT6 3,2 Can be displaced
shaft

1) For drawn cup, alignment and combined needle roller bearings, refer to Shaft and housing tolerances, page 610
2) The envelope requirement (symbol � from ISO 14405-1) is not shown but applies to all tolerance classes
3) For large bearings (D > 250 mm), or temperature differences between the outer ring and housing > 10 °C (18 °F), tolerance class G7� should be used
instead of tolerance class H7�
4) For large bearings (D > 500 mm), or temperature differences between the outer ring and housing > 10 °C (18 °F), tolerance class F7� should be used instead of tolerance class G7�
5) A split housing is allowed provided housing halves are well aligned during machining of the housing, with relief chamfers at the split
6) For D > 500 mm, use Ra = 6,3 µm
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