The nock is a cylindrical piece of wood, the exposed
portion being flush with the surface of the arrow shaft. The Siloflex
model nock is rebated on one end to inset into the shaft with a tight fit.
Opposite sides of the exposed nock are notched for finger grips, and a
string slot is cut into back end to receive the bow string. Some material
is removed from the center of the shaft end to lighten the nock.
(Thanks, Brun
Canutteson! Siloflex version shown)
(Thanks, Carolus von Eulenhorst! Golf tube version shown.)