suburban middle seat belt floor bolts

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annettemarie

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I beg you all tell me what grade this dang bolt is? Im going nutso with these bolts. I want to replace them with hex head since the stupid torx bolts suck. I know its metric ( M12) and the thread size is 1.75 but the grade is where im stuck.
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annettemarie

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FYI the RED arrow is pointing to what I believe is a nick from the torx bit. Not the machined markings
 

Turbo4whl

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Seat belt bolts are very special. They are made to lock in place like a stover nut does. (distorted thread) If you look close you will see the bolt is not perfectly round, but more like a triangle, this distortion locks the thread.

Grade wise, at least 10.9 or 12.9

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bucket

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For future reference, if you heat them from the underside, they come out real easy.
 

annettemarie

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Chevrolet Suburban V10 Silverado
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Thank you so much that is a big help. I did heat them and it still took 2 days of PB blaster and then Free All, three Torx bits and a torch. They were really rusted in there. I wanted to be certain I use the right grade for my daughters safety. Thanks for being so quick and for the picture Turbo4wheel
 

annettemarie

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Annette
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1988
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Chevrolet Suburban V10 Silverado
Engine Size
5.7
Do you guys think one of these bolts is a better choice than the other? I wonder if the phos & oil bolt will prevent it from locking down as tight even with a thread locker. Thoughts?
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bucket

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Normally I'd say the yellow zinc bolts may tend to rust faster, but these days, the quality of the coatings seems to be hit/miss.
 

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