FAQs
Preventive measures against breaking of self drilling screws
Fracture for broken cap, broken tail, broken rod, often occurs in martensitic carbon steel self drilling screw, martensitic carbon steel self drilling screw through high temperature carbonitriding surface hardness reached ≥560HV, with strong penetration, but also increased the brittleness of the screw.When the self drilling screw in the case of excessive load, excessive torque, easy vibration will occur brittle fracture phenomenon.When the self drilling breaks, it will not only affect the construction progress, not beautiful, but also bring a series of safety hazards.There are mainly the following aspects to prevent the breakage of drilling screw:
1:
Choose
the
right
product
a: Before use,
confirm whether
the mechanical
properties of
the product can
meet the
requirements of
use
b: Reasonable
selection of
screw size and
length
C: It is
recommended to
use half tooth
or double tooth
product in
interlayer
environment
2: Use
the
number
A: Use 4-6
screws per
square meter
B: The number of
roof and heavy
plate should be
increased
appropriately
C: Wind area is
larger
appropriate
increase dosage
3:
Correct
use
method
A: Tap
perpendicular to
the axis of the
thread, do not
tilt
B: In the
tightening
process, the
force must be
uniform, and the
tightening
torque should
not exceed the
safety torque
C: 12#, 14#
specification
products,
electric drill
speed 1000-1800
revolution can
not be too fast
4: Failure torque (below data for reference only) unit: N.m
|
specifications |
Destroy the torque min |
|
4# |
1.5 |
|
6# |
2.8 |
|
8# |
4.7 |
|
10# |
6.9 |
|
12# |
10.4 |
|
14# |
16.9 |