How to ensure screws are properly tightened - Petzl USA
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How to ensure screws are properly tightened

Many Petzl products are fastened or locked with screws. The tightening torque must be respected and inspected regularly, especially if the device is used intensively.

Warnings

  • Carefully read the Instructions for Use used in this technical advice before consulting the advice itself. You must have already read and understood the information in the Instructions for Use to be able to understand this supplementary information.
  • Mastering these techniques requires specific training. Work with a professional to confirm your ability to perform these techniques safely and independently before attempting them unsupervised.
  • We provide examples of techniques related to your activity. There may be others that we do not describe here.

1. Respect the tightening torque

To ensure proper performance of your device, the screws must be correctly installed and tightened to the torque indicated in the Instructions for Use.

The tightening torque reduces the possibility of the screw loosening during use.

RING OPEN, tightening torque.
ASAP LOCK, tightening torque.
ASTRO, tightening torque.
EJECT, tightening torque.
MICRO GRAB, tightening torque.
CHICANE, tightening torque.
MGO OPEN - EASHOOK OPEN, tightening torque.
SWIVEL OPEN - MICRO SWIVEL, tightening torque.
SEQUOIA, tightening torque.
CANYON GUIDE, tightening torque.
TRAC, tightening torque.

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2. Use a torque wrench

A simple wrench can be used to properly tighten a screw, but it does not allow verification of the tightening torque.

Using a torque wrench is the only way to verify that the tightening torque is correct.

Using a torque wrench is the only way to get the correct tightening torque.

3. Inspect the tightness

Inspection before and during each use:

Inspection must be carried out by a competent person.

This inspection can be done quickly and without equipment, by following the Instructions for Use.

- Visual inspection:

If the red O-ring is visible, the screw is not tight enough.

If the red O-ring is visible, the screw is not tight enough.

If the head of the screw is visible when it should be hidden, the screw is not tight enough.

The screw is not tight enough if it is visible, 1/3.
The screw is not tight enough if it is visible, 2/3.
The screw is not tight enough if it is visible, 3/3.

- Manual inspection:

If the spacer moves (RING OPEN, SWIVEL OPEN...), if the piece is loose (ASAP LOCK...), the screw is not tight enough.

The screw is not tight enough if the spacer moves, 1/3.
The screw is not tight enough if the spacer moves, 2/3.
The screw is not tight enough if the spacer moves, 3/3.

Verifying the tightening torque during each PPE inspection:

Verification of the tightening torque, using a torque wrench, must be done during every regular PPE inspection. WARNING: intensive use (e.g. adventure park) may require more frequent PPE inspection, especially the screws’ tightening torque.

Information

Using thread lock

• For intensive use, to help prevent accidental loosening, thread lock may be used to secure the screw (see the thread lock’s instructions for use).

• Thread lock can make disassembly difficult or impossible, depending on the thread lock used. This solution is suitable for long-term installations.

Thread lock.