Ceiling Fan Mounting - Machine Screws


  #1  
Old 01-31-20, 01:59 PM
I
Member
Thread Starter
Join Date: Mar 2007
Location: Jupiter
Posts: 180
Received 1 Upvote on 1 Post
Ceiling Fan Mounting - Machine Screws

Folks,

Are machine screws man enough to hold the fan motor assy to the Ceiling Box? It has that option in the fan installation manual. I'd like to go that route as I've already had to replace the 3 in outlet box with a 4inch just so the Fan mounting bracket will fit. I have the box mounted to the wooden crossmember by way of 4 off 2 inch woodscrews so that is going nowhere. I have 1 inch machine screws that I intend to Loctite in place. I'm just wondering if the weight of a 44 inch fan will strip them out of the box. The 2 screws attach to the outer 'lips' of the 4 inch round outlet box and the mounting bracket lines up nicely with those screw holes so if I can hang the fan using those that would make life easy.

Thanks

 
  #2  
Old 01-31-20, 02:17 PM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 8,043
Received 517 Upvotes on 422 Posts
Machine screws are fine if the box is a fan rated box.
 
  #3  
Old 01-31-20, 02:21 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,965
Received 725 Upvotes on 641 Posts
IIRC it uses an 8-32 machine thread. That's good for holding a fan.
 
  #4  
Old 01-31-20, 03:31 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,108
Received 3,986 Upvotes on 3,578 Posts
Most fan boxes use 10-32 screws.
The box you are describing is a standard fixture type 4" round box and is not fan rated.

Name:  4.jpg
Views: 2785
Size:  14.3 KB
 
  #5  
Old 01-31-20, 05:36 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 10,965
Received 725 Upvotes on 641 Posts
Most fan boxes use 10-32 screws.
Thanks for the correction PJ.
 
  #6  
Old 02-01-20, 04:55 AM
B
Member
Join Date: Oct 2015
Location: Ct.,USA
Posts: 3,239
Received 303 Upvotes on 268 Posts
What are the other options? Unless the fan manufacturer also includes the ceiling mounting box and the mounting screws (he controls the acceptable tolerances) you could end up with a screw on the small end of the screw tolerance and a threaded hole on the large end of the hole tolerance. If I wanted to go with my own box, I would have a nut welded on the inside of the box's threaded hole tab that double or triple the number of threads to engage the fan mounting screw.
 
  #7  
Old 02-01-20, 07:03 AM
M
Member
Join Date: Oct 2005
Location: Florida
Posts: 1,648
Received 7 Upvotes on 6 Posts
Fan rated boxes where I am do not have the thin threaded bent tabs for mounting. They have full depth mounting holes so the machine screws mated all the way in and not just dangling on two threads.
 
  #8  
Old 02-01-20, 11:00 AM
I
Member
Thread Starter
Join Date: Mar 2007
Location: Jupiter
Posts: 180
Received 1 Upvote on 1 Post
Let me circle back to Lowes. I take all your points. I saw this one and thought it doesn't even have the machine screw length that I will use. Ideally what I need is a 4.5" box and then the fan 'holder' will fit inside and I can then screw it down to the joist. That way it will never come adrift.
Thanks for the info, all good points.

https://www.lowes.com/pd/RACO-1-Gang...al-Box/3129641



 
  #9  
Old 02-01-20, 11:12 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Jersey
Posts: 65,108
Received 3,986 Upvotes on 3,578 Posts
There are many different fan boxes. Each one is dependent on its mounting location.
Some of these boxes use 10-24 screws.

Name:  fb.jpg
Views: 3041
Size:  42.8 KB
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: