The 24 Hours of Lemons Forums → Lemons Tech → is there such a thing as Metric Grade 8?? lap belt mounting to OE loc
I don't seem to be able to find metric hardware specifically marked grade 8. I Wanted to mount our harness lap belts into the factory seatbelt attachment bungs... with nice new hardware. I still have the OE factory seatbelt hardware that fits the factory bungs.. will this combination suffice?? or does it need to be grade 8?
factory belt hardware will most likely be 7/16" fine thread, even if every thing else in the car is metric.
There's no such thing as grade 8 metric hardware. The grades are defined by an SAE standard for inch series hardware. Metric fasteners use a "property class" that is roughly equivalent to grade. The number will be embossed on the head of the bolt. Property class 10.9 is approximately equivalent to grade 8.
Your original seatbelt hardware should be good, but I'm not the final judge. Maybe John will chime in.
Edit: or he might reply while I was composing the post. FYI we used the OEM stuff in our car.
Schroth stuff comes with 10.9 bolts.
yep metric 10.9 We used it all over our car, including seat and belt mountings, no problems
Metric 8.8 is roughly equiv to grade 5
Metric 10.9 roughly equiv to grade 8
There are differences and no direct cross, but in the automotive case, those two are pretty much interchangeable class in class.
Here's a pretty nice article re this:
http://www.rockcrawler.com/techreports/ … /index.asp
and compare tensile strengths using this chart for metric:
http://www.k-tbolt.com/bolt_chart.html
Std seat belt bolts are 7/16" as stated above.
Thanks.. all this info helped. I thought every bolt on this little car was going to be metric and I was trying to keep apples with apples. But you guys were right. 7/16 fine thread grade 8 went right in it's place and works out great.
Just a FYI.
We had our belts mounted to the stock location with a Corbeau seat. Raced 4 or 5 times like that til Eagles Canyon last year where they said the lap belt angle was not 45 degrees. So we had to relocate the lap belt mounting points.
7/16" = 11mm
Thanks.. all this info helped. I thought every bolt on this little car was going to be metric and I was trying to keep apples with apples. But you guys were right. 7/16 fine thread grade 8 went right in it's place and works out great.
Ha, that's funny as hell - my Dodge Dakota has SAE everywhere... Except the seatbelts. The real killer is that it's only one seating configuration that has metric. The belts for that configuration mount to a different spot and need longer bolts, and I guess they were worried about the plant fucking it up.
7/16" = 11mm
Good luck finding an M11 bolt.
sergio wrote:7/16" = 11mm
Good luck finding an M11 bolt.
86-93 Taurus use 11mm caliper slide bolt, it's a torx drive. Can't use it for belts though.
SHO 3.0 & 3.2L cam sprocket bolts are 11mm.
Yep, for some reason 7/16" fine is the standard for seat belt bolts no matter where the car comes from. The furrin cars come with 7/16 threads and metric heads, pretty weird.
Go hit the junkyard and pull the seat belt bolts from some similar japanese or european car. It will have the right thread pitch (usually a super fine) and high strenght bolt. That's the cheapest and least hassle version.
The next option is go to MR. metric, online or Olander Corp online and find the right M11 x X.XX bolt. more hassle with getting the right size/pitch bolt.
The 24 Hours of Lemons Forums → Lemons Tech → is there such a thing as Metric Grade 8?? lap belt mounting to OE loc