Nitriding or Xylan on threads
Nitriding or Xylan on threads
(OP)
Hi All,
I would like to clarify the doubts I have.
1. Threads with xylan coating is usually preferred. However, some threads are nitrided. Why is this so?
My colleague mentioned that nitriding on thread may cause galling. But in one written specification, it is said to prevent galling. I am confused, what is what?
Therefore, I would like to ask when do we do nitriding or xylan on threads.
Thanks for all the help given. Truely appreciated.
Jeffrey
I would like to clarify the doubts I have.
1. Threads with xylan coating is usually preferred. However, some threads are nitrided. Why is this so?
My colleague mentioned that nitriding on thread may cause galling. But in one written specification, it is said to prevent galling. I am confused, what is what?
Therefore, I would like to ask when do we do nitriding or xylan on threads.
Thanks for all the help given. Truely appreciated.
Jeffrey





RE: Nitriding or Xylan on threads
Xylan is a polymer coating that works great as an anti-seize and dry film lubricant, while also providing some corrosion protection. But one issue with relying on film coatings for corrosion protection of screw threads or surfaces subject to high contact stress/sliding, such as bolt/nut flanges or wrenching surfaces, is that the film coatings sometimes tend to get abraded off when the fastener is installed.
You did not mention details of your application, but I can't think of any situation where Xylan would not be a better choice than nitriding in terms of preventing galling.
RE: Nitriding or Xylan on threads
Thanks. I have the same reasoning as you.
In this case, the application here is the stem used in the gate valve.
The stem itself consists of threads and main body. I understand the rational behind for doing nitriding for the body.
In this case, can we do nitriding and follow by xylan coating on the thread itself?
Thanks,
Jeffrey
RE: Nitriding or Xylan on threads
RE: Nitriding or Xylan on threads
RE: Nitriding or Xylan on threads
RE: Nitriding or Xylan on threads
RE: Nitriding or Xylan on threads