Sourcing Grade 8 bolts.....

[TR6BILL]

I am replacing all the hardware that holds my diff and axles together with new stuff. Went to an are industrial nut and bolt specialty store (the have everything) and got everything I needed, except the bolts that hold my axle flanges together. All the grade 8 bolts available for this application and in that length, were threaded all the way to the cap and either too long or too short. Bummer. Dave at TRF to the rescue. They have the correct high-strength bolts in stock that they source in the UK. They are on the way. Figured it was time to change these babies out, they were only 35 years old.

 

[TR4]

Good ol Dave, if you ever get the chance, stop by TRF and visit him. John is another good one to talk with. I beliive both have been there since the birth of the company.

 

[TR6BILL]

Good ol Dave, if you ever get the chance, stop by TRF and visit him. John is another good one to talk with. I beliive both have been there since the birth of the company.

Having dealt with Dave for many years over the phone, I managed to sneak a visit to TRF several years ago, unannounced. I walked into the front door and greeted the old-ex-hippie-looking dude behind the counter with a "Hi!" in my best southern drawl. The guy behind the counter said, "Bill!" Amazing! Dave and John and Charles gave me the grand tour of the facility. All nice guys. Like having an E-ticket to Disneyland.

 

[Tinster]

Hey Bill !!

If you are replacing the fasteners because they are
35 years old- maybe you should install new Spicer U-joints
while you are at it. It's not not much added work or cost.

I replaced all mine and yes, I got the grade #8 from
TRF.

best wishes,

dale

 

[DNK]

Bill, Try the aircraft suppliers on line too. They have all kinds of different
grips and nominal lengths

NUTS and Bolts

 

[BobbyD]

Guys.....I had this same conversation last year with the Triumph and 6-Pack Mail Lists because the TRF & Moss price per bolt was in the $2 & $3 range. The reason for the price is that these are "special" bolts that have a precision ground shoulder. A stock bolt, be Grade 5 or 8 or standard does not have this type of shoulder.....with the result being an improper fit where you need it most.....at the shoulder. We had the same conversation about Locating Dowels used for various engine and tranny alignments. Someone actually just gave me an excellent explanation, quoted below.

Bottom line is that a bolt is not just a bolt depending on how and where you're going to use it. The drive shaft, axles, calipers etc all require these special bolts with precision ground shoulders.

<div class="ubbcode-block"><div class="ubbcode-header">Quote:]Locating Dowels are ground to less than a half thousandth for a precision fit. A miss alignment of .005 can wear out a spigot bearing and cause the input shaft bearing to also wear early. All regular bolts are undersized to fit the same size hole. I.E. a 5/16” bolt is three thousands under .312”, normally .309”. However this will vary with different manufacturers. The range for American manufacturers is around .3085 to .310. We should NEVER use Chinese nuts or bolts. They vary from .312 down to about .307. The metallurgy is far below SAE standards, they break at the absolute wrong time and is the most inaccessible place.. I only use grade 5 or above American bolts from any large fasteners company that will certify them American. [/QUOTE]

 

[IanF]

Sometimes, boltdepot.com is a good source.

 

[BobbyD]

McMaster, Bolt Depot, Nutty.com......... but you need to make sure you get bolts with precision ground shoulders.

 

[DNK]

That's why I like Spruce
See above post.

 

[BobbyD]

Don.......... what I can't find on the AN bolts that Spruce and other sell is whether that un-threaded shoulder meets normal bolt specs or precision ground specs. For example: a 5/16" bolt - the normal shoulder specs have a range of .3085 - .3105 = .002" variance. A precision ground bolt like what's used for the calipers, driveshaft, diff and axle flanges and/or a locating dowel have a variance of 0.000 to -0.0005". It's this extremely tight tolerance that leads to $3.00 per bolt and the difficulty in finding them at places other then TRF and Moss. The AN bolts have super high tensile strength but AN 5/16" x 1-1/2" AN bolt still only cost $0.30 At that price I was hoping for precision ground specs but can't find them anywhere for AN bolts.

 

[TR3driver]

There is a special series of AN- numbers for bolts with precision shanks. The common ones have the usual undersize shanks. There is also a "close tolerance" series, with shanks that are only slightly undersize (something like .0008 to .0012) as I recall.

 

[BobbyD]

Hey Randall.........you're the one who educated me about these precision shanks to begin with I've searched the usual bolt supply companies and can't find where any of them identify a "precision" bolt to buy. Is there another name or term that's used?
Thanks

 

[heliguy]

AN bolts are not considered "close" tolerance. I should clarify that. Standard AN bolts ie: AN3, AN4 etc are not close tolerance, but an AN173, or AN174 is.Other than that you need to go to an NAS type bolt. Google the "standard aircraft handbook" that should give you the info you seek, or maybe on Aircraft Spruce's website there may be information on each type of bolt.

 

[BobbyD]

Heliguy.........I'm trying to put together a bolt section for my web site but I'm also trying to replace all of the drive shaft and axle bolts which "require" close tolerance bolts. Can you direct me to a source and part number for close tolerance AN bolts that are 5/16-24 comparable? Thanks for the Google tip.

 

[heliguy]

Standard Aircraft handbook is the book you need. Gives all the info on grip length, over all length, diameter shank is ground to for a close tolerance bolts.
For a close tolerance ( ground to .0005 tolerance ) 5/16 bolt that is 1" 15/32 inches long you want a AN175-13A

 

[DNK]

Bobby- (got it right that time) this is what I thought I sent last time
Close Tolerance

 

[AngliaGT]

Also try your local Caterpiller dealer.
They make their own bolts,and are priced
very reasonably.They also have the best batteries.

- Doug

 

[BobbyD]

Don....yup, those are the ones...and as soon as you get into the NAS close tolerance bolts you're looking at $2-$3 per bolt which is consistent with TRF and Moss. Bottom line is....if you're going to replace the flange bolts for your drive shaft and axles, you're looking at close tolerance bolt at a premium price. The same holds true for the brake caliper bolts. Too many people balk at the price and use standard bolts which appear to work but allow for too much slop. A Grade 8 bolt is not necessarily a close tolerance bolt.

 

[DNK]

Don't forget those are Stainless and I bet a lot better quality from than the big 3

 

[BobbyD]

Don.... I'm sure they are of better quality. My whole point in this thread is that way too many people replace very critical bolts with Grade 8 when they should be using "close tolerance" or "precision ground" bolts.