Confused About Bolts

Post any Tech Tips or any matters and questions relating to upkeep
martin172
Posts: 1022
Joined: Thu Jul 22, 2010 2:14 pm

Confused About Bolts

Post by martin172 » Thu May 12, 2011 4:37 pm

I am about to refit the leaf springs to my car but I have a problem with the bolts.

I was going to use the originals bolts, but as I want to fit nyloc nuts instead of the original plain nuts, they are a little too short and so I need to buy some new bolts.

They are 7/16 UNF btw.

The grade marking on the originals appears to be an "S" which means that they are a grade 5, but the chart on Tigersunited says to use grade 8 bolts.

http://www.tigersunited.com/techtips/KJ ... Bolts3.asp

What should I be using, and if it is grade 8, any idea where I can get some from?

Cheers.

V8 burble
Posts: 278
Joined: Thu Sep 03, 2009 10:13 am

Post by V8 burble » Thu May 12, 2011 9:48 pm

I see no reason why you cannot use a longer OEM “S” bolt.

Try Namrick:

http://www.namrick.co.uk/acatalog/Home_ ... ts_18.html

martin172
Posts: 1022
Joined: Thu Jul 22, 2010 2:14 pm

Post by martin172 » Thu May 12, 2011 10:24 pm

V8 burble wrote:I see no reason why you cannot use a longer OEM “S” bolt.

Try Namrick:

http://www.namrick.co.uk/acatalog/Home_ ... ts_18.html
Thanks for the link G. :D
I'll give then a ring tomorrow.

I am just a little confused though as "S" bolts are grade 5 and I believe they should be grade 8.

Mal
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Joined: Sat Aug 02, 2008 5:39 am
Location: NZ

Post by Mal » Fri May 13, 2011 9:02 am

I am just a little confused though as "S" bolts are grade 5 and I believe they should be grade 8.
Martin.

They used grade 5 bolts because grade 5 was strong enough and would be a little cheaper to buy. It all adds up.The engineers used what they needed to use to do the job.

We like to up the power levels past what the car was originaly engineered for, so upgrading bolts etc makes sense.

When I went and bought the bolts for the rear springs, I was told suspension bolts need to be grade 8. So thats what I bought.

Cheers Mal.

V8 burble
Posts: 278
Joined: Thu Sep 03, 2009 10:13 am

Post by V8 burble » Fri May 13, 2011 7:59 pm

martin172,

If you are interested in stainless steel bolts in many different types, have a drool over this lot at AlloyBoltz:

http://www.alloyboltz.com/catalog/index.php

martin172
Posts: 1022
Joined: Thu Jul 22, 2010 2:14 pm

Post by martin172 » Fri May 13, 2011 8:47 pm

If Lisa finds me looking at them, she'll kill me. :lol:

After a day of phone calls, discovering that grade 8 bolts are like rocking horse manure, that there's a lot of confusion out there between grade 8 and 8.8 and that having bolts made can be expensive, I've bought some S grade bolts from Namrick. Thanks again G.

Just out curiosity, what do the specialists like Brian, Chris, Dean, David etal use for this job?

Mal
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Location: NZ

Post by Mal » Sat May 14, 2011 4:23 am


V8 burble
Posts: 278
Joined: Thu Sep 03, 2009 10:13 am

Post by V8 burble » Sat May 14, 2011 7:55 am

Mal,
Thanks for the technical info on bolts.

martin172,

You can try Margnor and Wright Auto Supplies, but I suspect that they only sell metric bolts in grade 8:

http://www.margnor-online.co.uk/

http://www.wrightsautosupplies.co.uk/

As you will see from this GT40 thread, we are not the only people in the UK desperate to find a source of grade 8 bolts:

http://www.gt40s.com/forum/gt40-tech-ex ... ource.html

Here is an extract from Mike Drew who worked on Panteras in both the UK and France.

“I spent a number of weeks working on a '72 Pantera in Surrey. I was astonished at how barbaric the UK is when it comes to individuals working on their own cars. Given that seemingly every third person in England is their own small sports car manufacturer, I would have expected to find hardware, tools, and auto parts practically growing on trees.

Instead, I found it next to impossible to even find metric nut and bolts; the only source for miles around was a 15-minute drive, and all they had was Chinese-made Grade Zilch junk, sold in blister packs, for about 10 pounds for a half-dozen nuts and bolts, of which a good 10% were defective.

And forget about SAE hardware. You might as well be looking for unicorn horns or something.

Eventually, I had to fly over with a whole suitcase full of nuts and bolts, both metric and SAE, just to get the damn job done. I had to do the same thing when working on another Pantera outside of Paris.

I live in a medium-sized town in California, halfway between Sacramento and San Francisco, with a population of about 100,000, in a very ordinary tract home development. If I pick up a rock, wind up really hard, and throw it as hard as I can, I can hit a wholesale hardware company that sells cad-plated nuts and bolts in bulk, and tools. How you guys can exist over there without that sort of thing, and yet still have so many fantastic cars on the road boggles my mind”.

Anybody going to the States soon with room in their suitcase?

martin172
Posts: 1022
Joined: Thu Jul 22, 2010 2:14 pm

Post by martin172 » Sat May 14, 2011 11:04 am

That is so true G.

I've had such a frustrating week, although it has been educational.

I spent endless hours phoning places and then driving there just to find that what they were saying was grade 8 were really grade 8.8 equivilant (grade 5).
You may laugh, but it got ot the point where I was questioning what they were saying and then after they'd checked, having to explain the grading system to some them.

I've now bought some "S" grade bolts for the time being and am going to casually try to find some pukka grade 8 ones.

Thanks for the info Mal.
I've seen one of those sites before but the second is new to me.
I think I've read practically every bolt site in the World this week. :lol:

garyv8tiger
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Joined: Sun Dec 30, 2007 10:57 am

Post by garyv8tiger » Sat May 14, 2011 6:37 pm

martin

have you tried one of the specialist .theres one in mansfield i think :mrgreen:

Mal
Posts: 672
Joined: Sat Aug 02, 2008 5:39 am
Location: NZ

Post by Mal » Sat May 14, 2011 9:37 pm

Here is an extract from Mike Drew who worked on Panteras in both the UK and France.

“I spent a number of weeks working on a '72 Pantera in Surrey. I was astonished at how barbaric the UK is when it comes to individuals working on their own cars. Given that seemingly every third person in England is their own small sports car manufacturer, I would have expected to find hardware, tools, and auto parts practically growing on trees.

Instead, I found it next to impossible to even find metric nut and bolts; the only source for miles around was a 15-minute drive, and all they had was Chinese-made Grade Zilch junk, sold in blister packs, for about 10 pounds for a half-dozen nuts and bolts, of which a good 10% were defective.

And forget about SAE hardware. You might as well be looking for unicorn horns or something.

Eventually, I had to fly over with a whole suitcase full of nuts and bolts, both metric and SAE, just to get the damn job done. I had to do the same thing when working on another Pantera outside of Paris.

I live in a medium-sized town in California, halfway between Sacramento and San Francisco, with a population of about 100,000, in a very ordinary tract home development. If I pick up a rock, wind up really hard, and throw it as hard as I can, I can hit a wholesale hardware company that sells cad-plated nuts and bolts in bulk, and tools. How you guys can exist over there without that sort of thing, and yet still have so many fantastic cars on the road boggles my mind”.
Wow, you guys do have a problem over there. I would have thought you would have easy access to bolts. Especialy UNF and metric. Where do all the atuo engineers get theirs from. I just go to the local fastner shop. You can't always get exactly what you want, but you will get close.

Seems like a good buisness oppotunity over there for someone.

martin172
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Joined: Thu Jul 22, 2010 2:14 pm

Post by martin172 » Sat May 14, 2011 10:31 pm

Metric and often used threads aren't necessarily a problem over here.
It's the rarely used or more specifically, the rarely purchased that are the problem.

One firm I contacted said that they could probably get some but would have to buy a box of 50 or 100, give me 4 and have the rest sitting on a shelf for the best part of a decade so aren't inclined to do it.

Mal
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Joined: Sat Aug 02, 2008 5:39 am
Location: NZ

Post by Mal » Sat May 14, 2011 11:36 pm

Martin. Where did you find the info on classification cross over,
ie S = grade 5. I have been cleaning up bolts off the front suspension with a T marking and would like to know what grade they are. This thread has been informative for myself as well. I just went out and checked the new bolts I got for my leaf springs. I am sure they said they were grade 8, but they are not. Only grade 5.
I want to know for sure when I replace the fulcrum pin bolts I am doing so with the correct grade.
One firm I contacted said that they could probably get some but would have to buy a box of 50 or 100, give me 4 and have the rest sitting on a shelf for the best part of a decade so aren't inclined to do it.
Shame they they have to buy in so many at a time. You would think it was worth the manufactures or supply companies to supply in smaller quantities.

martin172
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Joined: Thu Jul 22, 2010 2:14 pm

Post by martin172 » Sun May 15, 2011 11:07 am

Hi Mal,
One of the first places I contacted told me that S and 5 were the same and I figured out the rest by piecing bits of info together.

This site shows the values of lettered bolt grades

http://www.british-cars.org/mg-midget-s ... 910879.htm

This site shows the values of lettered bolt grades

http://engineershandbook.com/Tables/boltgrades.htm

So, what I ended up with was....

Grade S have a tensile strength of 112 KSI Grade 5 of 105 to 120 KSI

Grade T have a tensile strength of 123 KSI Grade 7 of 133 KSI

Grade V have a tensile strenght of 145.6 KSI Grade 8 of 150 KSI

This is ofcourse internet info so the usual caveats apply.

Hopefully someone can find a site with all the info together.

H, Sunny 65
Posts: 110
Joined: Mon Mar 10, 2008 11:40 pm

Post by H, Sunny 65 » Sun May 15, 2011 8:16 pm

If you want to buy nut's bolt's and other fixings. GTC Stainless steel, are based close to my work and will sell you just one nut or bolt if thats all you require.
http://www.gtc-direct.com/index.asp

Harry

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