Four-Bolt Square Flange
|
both dimensions represent the distance between bolt hole
centers
|
Typically made of cast iron, four-bolt square flanges provide greater
rigidity when mounted than two-bolt flanges. The NTN nomenclature
designations for this unit are F and FU.
The bolt holes are spaced equidistant from the shaft or bearing
bore. The distance between bolt hole centers is measured from the
center of one bolt hole to the center of an adjacent bolt hole.
The shaft size and the distance between bolt hole centers for four-bolt
flanges are listed in the appropriate NTN catalog. Table
4 below provides a brief example of the dimensional
details available. In the section listed, the details are provided
for a four-bolt flange fitting a one-inch diameter shaft. From this
you may select the proper distance or spacing between bolt hole
centers.
| Table 4: Four-bolt square flanged housing variations—1"
diameter |
4-Bolt
flange
housing type |
Insert
bearing
series |
Bolt
center
distance (inch) |
Application
duty |
F
FU
F |
2
2
2 (Adapter) |
2 3/4
2 3/4
3 17/64 |
Normal |
F
F |
X
X (Adapter) |
3 17/64
3 5/8 |
Medium |
| F |
3 |
3 5/32 |
Heavy |
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