|
Glossary of Fastener Terminology
L
Laps: Laps are surface defects caused by
folding over fins or sharp corners into the surface
of the material.
Lefthand Thread: A screw thread that is screwed
in by rotating counterclockwise.
Length: The length of a headed fastener is
the distance from the intersection of the largest
diameter of the head with the bearing surface to the
extreme point, measured in a line parallel to the
axis of the fastener. Exceptions: The length of a
shoulder screw and a socket head shoulder screw is
the length of the shoulder. The length of a flat top
countersunk head tubular rivet with chamfered top)
is measured from the intersection of the bearing
surface with the shank diameter to the extreme
point. The length of a headless fastener is the
distance from one extreme point to the other,
measured in a line parallel to the axis of the
fastener.
Length of Engagement: The axial distance over
which an external thread is in contact with an
internal thread.
Lock Nut: There are two common usage's of
this term:
-
A nut which provides extra resistance to
vibration loosening by either providing some
form of prevailing torque, or, in free spinning
nuts, by deforming and/or biting into mating
parts when fully tightened.
-
The term is sometimes used for thin (or jam)
nuts used to lock a thicker nut. When used in
this way the thin nut should be adjacent to the
joint surface and tightened against the thick
nut. If placed on top of the thick nut the thin
nut would sustain loads it was not designed to
sustain.
(Click on the
letters below to browse the glossary terms)
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z |
