Distance and material affects on magnetic full strength

[TonyL]

Hi Folks:

This is my first post, I hope that I observing the proper etiquette. If I have a magnet with a known pull strength is there a way for me to determine the affect of 1/4 inch plywood on the magnets pull strength when the plywood is placed between the magnet and the surface metal?

Thank you for reading!

 

[Dale]

Hi Folks:

This is my first post, I hope that I observing the proper etiquette. If I have a magnet with a known pull strength is there a way for me to determine the affect of 1/4 inch plywood on the magnets pull strength when the plywood is placed between the magnet and the surface metal?

Thank you for reading!

It will be almost the same as 1/4 inch of air. See the table here
https://en.m.wikipedia.org/wiki/Permeability_(electromagnetism)

 

[Bob Wolf]

Magnetic force on the metal surface is inversely proportional to the distance. I feel the plywood, a non ferromagnetic material, should not have any
significance to the outcome.

 

[Nidum]

Possibly more important is the effect of the 1/4 " stand off . A magnet produces much higher attraction force when attracted object is very near or in direct contact than it does when there is a significant gap .

 

[TonyL]

Thank you all very much. I see from the wiki article and your response that air and wood have a similar affect. I need to calculate the pull strength so that I can buy the correct magnet (pull strength) to allow for the 1/4 inch gap. I will conduct more research. Thanks again!