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164
THE DISTRIBUTOR’S LINK
BRUNO MARBACHER LOCKING FEATURES TO PREVENT ROTATIONAL LOOSENING from page 160
Durlok Flange Screw
VERBUS RIPP screws/nuts are harder than TENSILOK.
They are offered in property class 100; the strength
corresponds approximately to class 10.9/ 10. Hardness,
Durlok self-locking bolts/nuts are designed with
ramp shaped, radial teeth arranged uniformly into a
lightly conical outer surface. The plain outer bearing
ring prevents too much penetration into the clamped
member material. These properties produce adequate
edge pressure, enough to guarantee self-locking. The
Durlok bolt/Nut are fit for multiple reuses because the
serrations do not dig too deep into the clamped material
and still enable locking effectiveness.
12
Available in Property Class: 12.9, nuts property class
Dimensions: M6–M20
Ribbed Flange Bolts And Nuts
(Ribs On The Bearing Area)
The VERBUS RIPP screws/ nuts are a further
development of the TENSILOK fastening elements.
Instead of teeth on the lower side of the flange, they
have radial ribs on the entire bearing area.
While tightening the ribs are pressed into the material,
these ribs produce enough additional friction against a
spontaneous loosening.
However, they do not damage the surface of the
clamped part during dis-assembly.
at the surface amounts to 400 – 500 HV. Some
companies offer VERBUS RIPP screws in property class
12.9, upon request. They are also available as a socket
flange screw.
Since the round profile of the ribs penetrates more
lightly as a serration, VERBUS RIPP screws/ nuts have
to be tightened higher than TENSILOK.
Locking screws made of stainless steel and nonferrous
materials are too soft and therefore not feasible.
This is also not necessary, since joints with long screws
are immune to vibration. in the case of through hole joints,
locking screws and locking nuts must always be used.
Serration or ribs do not prevent the loss of already
loosened locking screw/ nut. It would require additional
locking features.
Dimensions: M5 - M16
There are many copies of the above-mentioned
screws and nuts – especially of the TENSILOK version.
Some serrated flange screws are manufactured in
property 8.8 (8). Such screws/ nuts have limited locking
effect since their serration does not penetrate the harder
work pieces as well.
As of this writing there are no standards covering
serrated/ribbed locking screws.
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