How-to Determine the initial torque categories

TLDR ; You can do a test by torquing a bolts to the different fixation conditions you want to have and read the angle of the wrench result to know how in which range you need to configure your “Tight / Loose / Very Loose” angles. This is only for the Ingersoll Rand QX wrench and the results vary depending on the airports use of bolts, washers & bases.

Introduction

One of the torque maintenance analysis is looking at the initial torque conditions. The Ingersoll Rand ALIS-compatible wrenches have the ability to measure the angle of rotation which can be used to determine the condition of the bolts before it was torqued ( very tight, tight, loose, very loose, no fixation). This data can be used to analyzed and adjust your maintenance routine which contribute significantly to ensuring a higher standard of safety within airport operations.

What is the initial torque conditions?

Table 1 - Understand the meaning of each condition

In this example, we use 25Nm as the target torque.

Category	Description	Angle of rotation
No fixation	The bolt is barely staying inside the base, this at the point where a person can remove the bolt from the fixture with their bare hands. (The description is approximate, you should already be concerned if your bolt is at the very loose condition). Less than 20% of target torque remains This status is a major safety Risk.	TBD by experiment
Very Loose	The bolt is being secured to the base at only 20-40% of the target torque. In this example, it means that the bolt is being fixed to the light with X < 6.25Nm This status is a major safety Risk.	TBD by experiment
Loose	The bolt is being secured to the base at 40-85% of the target torque. In this example, it means that the bolt is being fixed to the light between 6.25 ≤ X < 18.5Nm.	TBD by experiment
Tight	The bolt is being secured to the base at 85-100 % of the target torque. In this example, it means that the bolt is being fixed o the light with 18.75 ≤ X < 25 Nm.	TBD by experiment
Very Tight	The bolt is being secured to the base at 100-120% (Depending on the High-limit config in the wrench) of the target torque. In this example, it means that the bolt is being fixed to the light with 25 ≤ X < 30Nm.	TBD by experiment

Now we understand the meaning of each categories, we will now find the which angle correspond to these categories by doing an experiment.

Experiment to determine the initial torque conditions

Equipment and tools

Steps for determining Angle settings

Make sure you have first set the correct parameters for the Wrench as in. Get started with the Ingersoll Rand QX Wrench

1. Untighten a bolt to the just “hand tight”

2. Use the Ingersoll rand to record the angle of rotation to reach target torque. This is an indication of your angle for ANGLE FOR "NO FIXATION"

3. Untighten and retighten a bolt to the just about 20% of your target torque with the manual torque wrench.

4. Use the Ingersoll rand to record the angle of rotation to reach target torque. This is your max angle for ANGLE FOR "VERY LOOSE"

5. Untighten and retighten a bolt to the just about 40% of your target torque with the manual torque wrench.

6. Use the Ingersoll rand to record the angle of rotation to reach target torque. This is your max angle for ANGLE FOR "LOOSE"

7. Untighten and retighten a bolt to the just about 85% of your target torque with the manual torque wrench.

8. Use the Ingersoll rand to record the angle of rotation to reach target torque. This is your max angle for ANGLE FOR "TIGHT"

9. Untighten and retighten a bolt to the just about 120% of your target torque with the manual torque wrench.

10. Use the Ingersoll rand to record the angle of rotation to reach target torque. This is your max angle for ANGLE FOR "VERY TIGHT"
    

You can do the above multiple times for each value and taken an average of your different results for a more accurate setting

Example Data collected and result

We read the values and record them in this table.

Conclusion

This allows us to fill in the “Torque Settings in ALIS as following

Now, it’s your turn to do this experiment on your airport! Before you go, don’t forget to check out the FAQ below.

Extra

The variation in values depends on:

• If your airport is using the extension bar or not

• What kind of base is the airport is using

• Is the airport using loctite, type of washers, coated bolts etc.

How much “Torque” the Initial Torque condition would be will also be influenced by the factors above.

You can read the values from:

What is the angle of rotation and how to measure the angle of rotation?

1. ALIS iOS app (ALIS can keep the recorded values for you)

2. The INSIGHTConnect app (you can retrieve the data recorded from the tool log to get an excel sheet)

How to determine the target torque values

ADB Safegate has manuals which give recommened values for each type of airfield lights.

Example: AXON - Runway Centerline

If you go to section INTEROPERABILITY of the manual, you will see the recommended values for different situations.

Remark: some ADB Safegate manuals will refer to Reference EB83, you can read about it here: Federal Aviation Administration which is an Engineering Brief (EB) that provides information and guidance for standard methods to be employed when using stainless steel or coated carbon steel bolts to secure light fixtures to L-868 light bases.

In summary the values depend on if you use loctite, washers, etc., which can vary between airports and the user’s experience.

In this page, we use 25Nm as the target torque for our experiment.

What if you use the extension bar for your airport? What if your airport uses a different target torque?

We recommend that you do the experiment based on how you would normally do your torque maintenance. We also did an experiment with the extension bar and these are the resutls:

How to find the toruqe settings? how to find the initial torque conditions?

Setting → Maintenance → Torque Settings