Post on 06-May-2018
Leada Acrow Friction Bolt (90983)
It has come to light, after a failure on site, that there has been a manufacturing defect on the above
product.
The head of the Friction Bolt should be manufactured from a 38mm x 36mm x 10mm thick steel
plate, with a 1.5mm deep groove running parallel to the 36mm long face.
This allows the bolt to be inserted into the channel on the Super A Beam with numerous grooves
biting onto the aluminium to achieve the desired fixing and friction. (See Figure 1)
Figure 1
The latest batch of Friction Bolts have been manufactured with the grooves running perpendicular to
the 36mm long face, meaning when inserted into the Super A Beam, only one or two grooves are
biting in, but in the wrong direction giving a greatly reduced load capacity for the item. (See Figure 2)
Figure 2
Figure 3 shows the differences between the two batches of bolts that Leada Acrow have been
supplied. The correct Friction Bolts are the darker ones on this photo.
Figure 3
To eliminate any risk of the wrong Friction Bolts being used, could all sites on AWPR please look into
what bolts you have on site, and quarantine any that are as shown on Figure 2. We will then replace
these with the correct ones as shown on Figure 1, free of charge.
As a company, Leada Acrow are also carrying out this exercise in the depot to ensure that the
incorrect bolts cannot be distributed to customers. Our manufacturer is now looking into rectifying
the manufacturing process to ensure this does not happen again.
The Friction Bolts, when used in the correct orientation have a load capacity of 10kN. When used in
the wrong orientation have a load capacity of 0.12kN, so as can be seen, this is the reason for
movement at the shutter joints.
To ensure that overtightening does not occur, and the components are not subject to excessive
force, Leada Acrow recommends that the Friction Bolts are tightened using a torque wrench set to
50Nm.
Please see the final two pages of this bullet-in for the correct and incorrect orientation of the
Friction Bolts. Please ensure that these are passed to all concerned to ensure the incorrect bolts are
not used.