Helicoil

[lele]

I need to put one helicoil in a stripped thread...is better to use some loctite on the outside surface of it or is not necessary??

 

[LKLD]

I wouldn't. We use them at work, and haven't had one come out. However, we have had them get buggered up, and replaced them. Loctite would make replacing them a real pia.

 

[08FJR4ME]

Not needed,

 

[garauld]

Since helicoils are SST, I would put a small drop/dab of oil/grease on the screw before installing into the helicoil. I always use lube on SST screws as they have a tendancy to gall the mating threads - a bad thing.

 

[bergmen]

Since helicoils are SST, I would put a small drop/dab of oil/grease on the screw before installing into the helicoil. I always use lube on SST screws as they have a tendancy to gaul the mating threads - a bad thing.

Excellent point and not commonly known. Stainless steel fasteners can and do gall (especially if the same alloy is used in both fasteners). No problem when using stainless with aluminum (or any other metal).

I ran into this issue with one of my major projects at work. I had to change the pressed-in nuts (Pem nuts) to zinc plated carbon steel since all of our machine screws and bolts are out of stainless.

Dan

 

[eastern5]

So I just wanted to ask because the one time I had to helicoil something it was aluminum body, stainless helicoil and stainless bolt. I had tapping fluid to assist and when completed, inserted the helicoil. after all this, inserted the ss bolt. am I going to have an issue with this bolt later? I just did not want the lubrication to change my torque down value, as this is part structural.

 

[bergmen]

You could get a "cold weld" or galling situation but you probably would have noticed resistance upon initial assembly. The lubrication effect on torque is somewhat minimal depending on the application but I would (just to be safe) apply a little oil or grease and adjust torque accordingly. Otherwise you can risk having the heli-coil come out with the bolt the next time you disassemble.

Dan

 

[eastern5]

well, the installation was very smooth. hmmm, something to look at next time.

 

[TownsendsFJR1300]

I just put an M6 x 1 heli-coil in an aluminum, custom made, center triple nut.

It was to be used to mount a stem mount for a GPS. I used 1.5 coils (I had enough aluminum there) for full use of the nut.

I did use red locktite and let dry over night. I ran a tap thru it the next day, assembled and used red locktite again for the stem mount.

Super solid and its NOT going anywhere..