ratc

ratc

Well Known Member
When checking some nutplates I have found a few that appear to be cross threaded when the screws are inserted. :mad: The screw does reach the "crimped" end. Although I could replace them it would be difficult. I have thought about trying to tap them out and start over or drill out the thread and try to attatch a captive nut on the end of the nutplate.
The nutplates are not in areas of high stress.
Any other ideas or experiences greatly received.
 
Nutplate Problem!

My original post should read that the screw does NOT reach the "crimped" end
Sorry for the confusion :(
 
Run a tap through

You could get a tap going through it, but not quite all the way so that there is still some resistance. If you end up needing to go all the way, you could always use a bit of loctite on the threads when you put the screw in for final assembly.
 
nutplate ****..

Yep, put me down too as one who taps out, all the way, ALL nutplates. Then blue locktite will keep things snug for several screw removals. The damage caused by trying to remove damage philips head screws later will FAR outweigh your frustration in the possiblilty of some trim screws possibly backing out later.
*** Note, when I say ALL nutplates, I am refering to any nutplates that are #8 or smaller that use phillips head screws. Nutplates that hold hex bolts are typically structural, for flight controls, etc, and should NEVER be tapped out.
 
Use a tapered tap

Like Mickey says, you can run a tap through it.

Using a tapered (not plug or bottoming) tap in a hand wrench should allow you to go as far as you need to chase the threads just enough without completely opening them up and losing the locking feature. 2 flute taps have a longer taper than 4 fluters.
 
ratc said:
When checking some nutplates I have found a few that appear to be cross threaded when the screws are inserted. :mad: The screw does reach the "crimped" end. Although I could replace them it would be difficult. I have thought about trying to tap them out and start over or drill out the thread and try to attatch a captive nut on the end of the nutplate.
The nutplates are not in areas of high stress.
Any other ideas or experiences greatly received.
Click to expand...

If in fact the nut plate is cross threaded it will have to be fixed. My solution to nutplates was to rake the screw across a stick of door ease. I would not put a screw in a nut plate without the door ease. I know people run taps through nut plates but i would never do that, thats just my opinion
 
Resmash after tapping

I have had to run a tap through a few platenuts but sometimes it was difficult not to loose the locking feature by going too far. When that happens, I just take some pliers and carefully resmash the end to give it the oval shape. It's not hard to do.
 
ratc said:
When checking some nutplates I have found a few that appear to be cross threaded when the screws are inserted. :mad: The screw does reach the "crimped" end. Although I could replace them it would be difficult. I have thought about trying to tap them out and start over or drill out the thread and try to attatch a captive nut on the end of the nutplate.
The nutplates are not in areas of high stress.
Any other ideas or experiences greatly received.
Click to expand...

Have you carefully inspected the alignment of the bolt hole in the parent material and the nutplate? Misalignment here will cause you to cross thread the screw in the nutplate.
Using a tap as suggested earlier can correct this problem, PROVIDING you keep the tap perpendicular to the material.
Charlie Kuss
 
ratc said:
My original post should read that the screw does NOT reach the "crimped" end
Sorry for the confusion :(
Click to expand...


I use Beolube on the screw the first time I use a nutplate. Makes the screw go in so much easier and you still get the locking capability of the original nutplate.
 
I buy hardened hex socket drive machince screws, lube them up with some Boelube (the waxy stick kind), and run them in and out of each nutplate before installing the real screws, also with some Boelube. This burnishes the nutplate threads, smoothing them up to prevent seizing, while still maintaining plenty of prevailing torque to keep the self-locking action. A hex drive adapter in an electric screwdriver makes the job go quickly.
 
Thanks for all of your very useful comments. I have checked the alignment of the problem nutplates - They are not quite lined up with the holes!!
Obviously that was the start of the problem. I will tap them out to a point just before the squeezed end and use some loctite. ;)
 
Never had a platenut thread problem

If I had such a problem and it was in a position that the risk of removal was greater than the risk of taping I would tap without hesitation. If you are using floating platenuts it is best to use a same hole pattern non-floating platenut as the drill guide. My procedure for #8s is drill a #30 hole, clecoe the drill guide to the hole with a bronze clecoe (1/8"), drill a #40 mounting hole, clecoe it with a silver clecoe, drill the other #40 mounting hole, remove everything, countersing the mounting holes for the AN426AD3 rivets, drill out the #30 hole to 3/16", debur the holes and mount the plate nut. If you are usung floating platenuts be careful not to mash the retainer tabs down on the floating element. I would not use loctite. Just one guy's approach.

Bob Axsom
 
ratc said:
Thanks for all of your very useful comments. I have checked the alignment of the problem nutplates - They are not quite lined up with the holes!!
Obviously that was the start of the problem. I will tap them out to a point just before the squeezed end and use some loctite. ;)
Click to expand...

Andy
So the real problem was alignment of the nutplate to the hole. Not an uncommon problem. Be sure to hold the tap perpendicular to the nutplate. This will force the tap to cut threads on the offending side of the parent material. This will allow normal insertion of the fasteners. Stay away from the crimped area with the tap. Odds are, you won't even need the Loctite.
Charlie Kuss ;)
 
Would replacement with a floater nutplate be considered a preferable solution? It could be pop-riveted in place if access is a problem.
 
Nutplate problem

Paul - Yes, it is a possibilitly. I like options, it's always nice to have a backup, backup plan :)
 
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