Hitachi NR90GC - 3-1/2" Gas Powered Clipped Head Framing Nailer Technical Data And Service Manual page 54

Housing Ass'y [74]
Cylinder Ass'y [42]
Cylinder Plate [57]
Seal Lock Hex.
Socket Hd. Bolt
M5 x 10 [58]
Cylinder Plate [57]
Section A --- A
Convex portion of the
Cylinder Ass'y [42]
Convex portion of the
Cylinder Ass'y [42]
Fig. 46
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Blade Guide [53]
Driver blade
Make the Cylinder Plate
[57] contact with the
convex portion of the
Cylinder Ass'y [42]. Do
not overlap the cylinder
Plate [57] on the convex
portion of the Cylinder
Ass'y [42].