Make small nuts and bolts hold fast?

[Bennylava]

I recently put new weather stripping along my garage door. That standard rubber flap that has to be replaced about every 5-10 years. Well, i used nuts and machine screws to fasten them down, for a couple of reasons, but the main one was, I couldn't find any (locally) self tapping metal screws that had a flat head. I wanted the heads to be flush, and not sticking out and looking all half ***'d.

Unfortunately now the nuts are backing off the bolts. I tried to tighten them down pretty tight, but apparently pretty tight wasn't enough. Would loctite work in this instance? Or would the bolt need to be bigger in order for loctite to work? Here is a pic of what I'm talking about. I didn't use screws quite that long, this one will be used on my boat for something else. So I need to know for that project, as well as the garage door seals. But its all the same except for the length.

 

[ChevyEFI]

I have similar size (M5) nuts & bolts holding a door handle to the interior of my car door.

Simple lock washers (like what you pictured) have held. I can't imagine a garage door is a high-vibration application. Are the heads hitting the floor?

 

[theoldwizard1]

The head on those screws is called a pan head. Some are a bit flatter than others. Pan head sheet metal screws do exist, but probably not in that length.

Loctite will help ... a lot, eve on small screws.

 

[toolmandan]

I would use loctite, or a nylon lock nut, or a spring lock washer. Over-tightening something is never the way to get a screw and nut to hold!

 

[PCustoms]

Nylon lock nut.

You are compressing the rubber, which expands (and shrinks) according to outside temperature. When it shrivels the nuts gets loose.

Split washer would do the same thing, as soon as the rubber shrinks you loose all clamp force in the bolt and it backs off.

Nylock will stay in place, thread lock may work too but Nylock less of a hassle on small fasteners IMHO.

 

[JJThrasher]

Take a welder and tack the back of the nut to the bolt end. Real quick and easy, faster than loctite, and simple to undo with a grinder.

 

[toolmandan]

Take a welder and tack the back of the nut to the bolt end. Real quick and easy, faster than loctite, and simple to undo with a grinder.

JJThrasher reminded me of another of my favorite ways to make nuts and bolts hold, screw it down and tighten, then cut off the bolt leaving like 1/8" or so, the use your ball pein hammer to pein the remaining threads of the bolt down. It won't loosen that way if you get a good "mushroom" going! I'll combine this with welding the fastener on some times.

 

[gonmad54]

Double nut it.


Sent from my iPhone using Tapatalk

 

[G_P]

X2 on the nylon insert lock nuts. They'll stay put when the rubber shrinks in cold weather.

 

[BFHtime]

Loctite blue so you can get it off if you need to. You could use a lock nut, or a lock washer. The best would probably be using 2 nuts since that is a long bolt, tighten the first nut down, then tight the second nut hard while hold the first, essentially stretching the bolt slightly between the 2 nuts. The last should hold the best, just don't over do it and break the bolt.

 

[Bennylava]

thanks I'll get some from the hardware store

 

[toplessHO]

can also stake the threads with a pair of dikes(diagonal cutting pliers)
in a pinch fingernail polish may work in lieu of loctite