Front seat modification. Increase thigh support.

[Reddog99]

First off, "8.8" IS a metric strength rating. See this site for more info: http://www.roymech.co.uk/Useful_Tabl...s/Strength.htm

Secondly, M10 is a metric SIZE, not a strength rating.

[PetersRedYaris]

Originally Posted by Reddog99

First off, "8.8" IS a metric strength rating. See this site for more info: http://www.roymech.co.uk/Useful_Tabl...s/Strength.htm

Secondly, M10 is a metric SIZE, not a strength rating.

I am aware M10 is the size. I am also aware that 8.8 is a strength rating, but it is a class, NOT a grade. Like I said, they are measured differently. US bolts are measured in grade and metric bolts in Class. A class 8.8 bolt is NOT the same as a grade 8. See here-

http://www.boltdepot.com/fastener-in...ade-Chart.aspx

[...]your first post says the stock bolts are a grade 10.9, which is NOT correct. Again, it's a class 10.9. You can figure out the strength comparissons yourself, just remember US (grade) bolts measure strength in PSI, while Metric bolts (class) use MPa. Heres the conversion- 1MPa = 1N/mm2 = 0.2248 pounds/mm2 And you'll need to know 1 inch = 25.4mm

Have fun...

PS- I reread my post as can see how you misunderstood me. You do realize however that both class (or grade) and size contribute to a bolts strength. I meant that an M10 bolt is huge, and there are 4 of them holding the seat in place. So long as you don't use a low carbon bolt, they will NEVER break. In a major accident, the seat will be ripped from the car before the bolts snap...

[Reddog99]

Over-reaction? Maybe I had too much coffee this morning.
But I'll stand by my admonition about recommending, in a public forum, lower strength bolts for a safety related item like the seat hold-down bolts. There are a whole lot of people here who might follow that advice. Are you willing to take responsibility if someone got hurt because of it?

And remember, in a front or a rear collision, the major load on the seat would be taken by just two bolts, not four.

The original bolts are 10.9, so it's not my OPINION, it's Toyota's judgment about what is appropriate.