Modern Vespa

I decided to change my original tires today starting with the front. The bolts started off with about the same torque, but two of them got tighter the farther they came out. I figured there was a problem with galling of the threads so I gave them a shot of silicone spray and worked them back and forth until they came out with a reasonable amount of force. Inspecting the bolts did show galling on about half of the first full thread which I have cleaned up. Question is should anti seize be used on the bolts to prevent future problems?

I always use anti-sieze when the question of diddimilar metals or the possobility of galling is raised....

After spending some time cleaning out the front hub threads I did use the anti seize grease. Did a rear tire change today and no problems with galling. Used the anti seize on everything except the bolts that hold on the muffler as some have reported having to use locktite to keep these from backing out. Thanks to all the MV posts on tire changes for the GTS. Tire mounting and balancing is certainly worth doing yourself if you've ever given it a thought. As the local dealer here filed for bankruptcy I would have to take a chance on a non Vespa shop or travel 150 miles. Guess time will tell if the exhaust gasket will hold.

I would never spray any type of lubricant on to a wheel stud. I don't care how hard it was coming off.

I would avoid using silicone spray anywhere near anything that might ever need painting ever again.

Howdy, excuse my stupidity but what is galling?

Galling, according to ASTM standard G40 (2006), is: "a form of surface damage arising between sliding solids, distinguished by microscopic, usually localized, roughening and creation of protrusions (i.e., lumps) above the original surface". In other words galling is material transfer from one metallic surface to another caused by movement and plastic deformation.

Galling usually refers to adhesive wear and transfer of material between metallic surfaces during sheet metal forming and other industrial applications.

More specific to my original problem.

Thread galling seems to be the most prevalent with fasteners made of stainless steel, aluminum, titanium, and other alloys which self-generate an oxide surface film for corrosion protection. During fastener tightening, as pressure builds between the contacting and sliding thread surfaces, protective oxides are broken, possibly wiped off, and interface metal high points shear or lock together. This cumulative clogging-shearing-locking action causes increasing adhesion. In the extreme, galling leads to seizing - the actual freezing together of the threads. If tightening is continued, the fastener can be twisted off or its threads ripped out.