Help with Flanged Nuts

[Turbobill80]

My car came with the front bumper hanging away from the fenders. I'm trying to get the four Flanged nuts (2 at each fender) that pull the bumper cover tight to the fender. So far I've tried 6, 7 and 8mm plus 1/4 and 5/16in. Everything seems too small except 8mm and 5/16in which are too big. What size and kind of nut do I really need? I searched the forum but did not find an answer. Any assistance in this matter will be greatly appreciated. Thanks in advance.

 

[pacecarta]

m6x1.0

 

[Turbobill80]

Curiously the M6X1.0 nuts were my first choice, but I cannot get either the M6 or M7 bolts to start. My caliper seemed to show thread width on the stud of about 6.5mm. M6X1.0 bolts fit the metal clips on bumper cover so that size is in the area. Thanks for your reply.

 

[pacecarta]

thats what the illustrated manual shows for those two nuts
you can download the manual here , pg 42
Pontiac Trans Am Parts Catalog

 

[Turbobill80]

I tried a M6X1.0 die and I cannot get it to start on any of the 4 studs. I read the parts manual and it should be M6X1.0. I'm confused, I cannot even get a M7X1.25 die to start. Thanks.

 

[Turbobill80]

I pulled the bumper cover and tried the the M6X1.0 die without success. I then used a M7X1.0 die and successfully threaded the stud. In all likelihood, a speed nut of about 7mm was used on the unthreaded stud. In retrospect I probably should have used speed nut since M7X1.0 does not seem to be a common chassis fastener on firebirds.