Jump to content
HybridZ

Bolt Strength


Recommended Posts

I had all the bolts, washers, etc, Zinc plated and can not tell which bolt\bolt strength is supposed to go on rear suspention and front suspention\motor mount crossmember, I took pictures but everything was full of grease.

 

Any help would be appreciated...

 

Chris

Link to comment
Share on other sites

When I had all the bolts out of my suspension I went to a local "Bolt" store (that's all they sold, nuts and bolts) and just replaced everything with 12.9 supergrade stuff. I brought the guy the bolts, and he would go and get them for me. He said those are comparable, if not better than the ones I had brought in. Hope this helps

Link to comment
Share on other sites

Most bolts are marked with 4 or 7 or 9, I am assuming its the strength. almost need to look at another Z to check. I dont have a problem buying some new bolts, but I have already had them zinked. I am missing the mustache mounting nuts altogether. If I new the thread pitch i could just go to King bold and get some.

Link to comment
Share on other sites

Your Datsun bolts are made and marked to a JIS standard (Japanese Industry Standard) which is similar to the DIN standard but not the same. If you want to get into the numbers then it may be easier to check the DIN markings, Japanese info like

this is always difficult to find. I have always worked on the principle that the higher the JIS number the stronger the bolt, given that vital structural bolts on Japanese cars like on steering and brakes usually have the higher numbers eg from 7 up. While the non structural stuff is usually marked 4 and strips threads/breaks relatively easily.

 

Oh no, don't tell me I have been living/bolting a lie :)

Link to comment
Share on other sites

Current JIS fastener specs (JIS fasteners comply with current metric property class markings):

 

http://mdmetric.com/tech/threadtech.pdf

 

Unfortunately its almost impossible to find fastener marking specs for the late 1960s and early 1970s for JIS, DIN, etc. I still think that the markings on the Nissan fasteners from back then are proprietary internal markings for stock control and assembly. There's no consistency.

Link to comment
Share on other sites

Ok, that being said. Does anyone know what the bolt markings 7 or 9 on the rear suspention where the transverse link bushings are?, either they were 7's or the shop didnt give me back all the bolts.

 

BTW... you can bring your pile of nuts and bolts to me and I can sort them by where they go on the car. I can't post it here because I have to look at the bolts.

Link to comment
Share on other sites

To believe the higher the grade the better is not a fully true statement.

 

To hold tight over time, bolts need to be stretched close to their elastic mode. Otherwise, they'll get loose.

If you get 12.9 instead of 10.9 and you apply the same torque, you won't get the same bolt state. 12.9 bolt might get loose before 10.9...

 

Moreover, friction coefficient is one big contributor too. If you're trying to tighten bolts on rusted thread, most of the torque will be used to overcome friction instead of creating tension. That why bolt manufacturers such as ARP is asking us to use their moly lube to keep control of the torque as good as they can.

 

 

Link to comment
Share on other sites

Thanks for the offer Johnc, I know where most of the bolts go,with exception of the rear suspention, the nuts on the mustache bar, and other bolts that were left on the rear suspention are all marked with 9, but i do not have bolts for sized for the transverse link with 9's on them.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...