I had a complaint yesterday that countersunk screws on some machines we build are hard to initially break loose. Some of these screws have loctite on the threads.


I understand that once these screws are torqued the torque creates great friction between the countersunk head and the host material.


Is there any way of getting around this?

Dear Sir

It all depends on the kind of locktite used some are removable others you have to heat the threads with a soldering iron to break the bond

Marcel Beaudry

They might also try a tool called an impact driver to do the initial loosening, if it is more than just the Loctite making them hard to break loose. An impact driver is a hammer operated tool which gives a bit of a high energy twist-jerk to the socket attached to it.

For the stubborn ones, I would center punch on the face near the outer edge. Angle the punch to rotate the screw.

I had a complaint yesterday that countersunk screws on some machines we build are hard to initially break loose. ...

.....Is there any way of getting around this?

Is this a customer complaint about how difficult it is to break loose countersunk socket head cap screws?

We have had similar complaints; the key size is smaller on these screws than a regular socket head cap of the same diameter and that coupled with the increased friction from the countersink often results in the socket in the screw stripping out.

It is a difficult problem to combat but here is what we have tried:

Always use good quality screws, and supply a good quality Allen Key with the part to try and ensure the likelyhood of stripping is reduced.

Set the screws using a torque qrench to make sure they are not too tight; reefing them in way too tight is the biggest culprit.

Use the low strength Loctite.

In any literature for dis-assembly or maintenance put in a comment something like;

"the countersunk screws holding whatever together are torqued to whatever and secured with Loctite to reduce the possibility of them becoming loose in service. This can make these screws difficult to remove and it is essential to use a good quality Allen Key fully inserted in the socket for removal. Applying gentle heat to soften the Loctite and/or careful use of an impact wrench can be of assistance."

Basically CYA.