Special Processes - Technical reason concerning torque - Anaerobic compounds

[LAchey]

I would like to have a technical reason concerning torque and a separate process application of Anaerobic compounds are a special process?

 

[Bev D]

can you clarify your question?

I think you are asking why torque might be considered a special process, but I'm not sure of the context of the question regarding anaerobic compounds...

torque is considered a special process because it cannot be adequately ensured by merely inspecting it.

 

[LAchey]

I am asking two questions. 1. Is torqueing considered a special process? 2. Is applying an anaerobic compound, e.g. Loctite, considered a special process?

 

[Sidney Vianna]

Without context and relevant information, it is not possible to provide a meaningful answer. If you can't (or don't want to) provide details, you will not get an adequate answer.

 

[John Broomfield]

I am asking two questions. 1. Is torqueing considered a special process? 2. Is applying an anaerobic compound, e.g. Loctite, considered a special process?

Torquing is a special process unless you use something like this to indicate the bolt’s tension:

Direct tension indicator - Wikipedia

Excluding oxygen from the joint with an anti-vibration compound like Loctite would also be a special process unless you’ve devised a way of confirming the seal is airtight and vibration proof. Being as Loctite is generally well accepted you’d need only demonstrate that it is applied strictly in accordance with Loctite’s storage and application specifications.

 

[Sidney Vianna]

Torquing is a special process unless you use something like this to indicate the bolt’s tension

Why? Last week I took my car for tire rotation and balancing. Looking at the receipt, I noticed that there was an instruction to torque the bolts to 90 ft.lbs. With a calibrated torque meter, anyone can easily check if the bolts were torqued to that spec, plus/minus a tolerance.

Why is torquing a special process if it can be EASILY verified afterwards?

 

[John Broomfield]

True, we can verify the tool.

 

[Marc]

I'm with @Sidney Vianna - I have never heard of torque being a Special Process.

Definition - Special Processes - Can someone help us with a definition of Special Processes?

 

[John Broomfield]

The resulting product is not or cannot be fully verified.

We can virtually eliminate inspection by designing and validating our processes as if they are special.

 

[Bev D]

Sorry - Torque can be a special process. Breakaway torque is not the same as applied torque and the act of trying to measure the break away torque can change the interfaces, so trying to re-torque and achieving the same hold is difficult to assess as well. So there is no easy way to verify the applied torque after it has been applied. True we can use a calibrated and validated torque wrench (which of course is the point of viewing torque as a special process when the holding force is critical) to help ensure the applied torque. Adding to the complexity of this situation is ability of the material to hold the torque under stress (mechanical or thermal). You can achieve an applied torque then have the fastener loosen up over time. All of this adds up to many companies where the torque is a critical function and we treat it as a special process.