PLAIN SEAT
SPHERICAL COUNTERSINK
CONICAL COUNTERSINK
``The bore of the wheel fits very
closely to the hub spigot and the
wheel centers itself
``The countersink stud hole design
centers the wheel and keeps it in
position.
``British Standard / Imperial Standard.
``The spherical countersink is
expressed as a radius, e.g. R16
(radius of 16 mm).
``The shape of the countersink is
expressed in degrees, the most
popular being 90°, 80°and 60°. E.g.
with C90 (90°)
``The conical countersink is
expressed as an angle e.g. 60°.
Plain seat
Spherical countersink
Conical countersink
PLAIN SEAT
``This method produces the strongest seat, as no material
is removed. Being pressed rather than machined, indeed
the compression of the metal makes it harder and
stronger. Countersink can be conical or spherical.
Puching and forming...step 1
Step 2
Step 3
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