Hex bolt, brake drum to hub - replacement?

Taborljoshua

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One of my hub bolts snapped at around 90ft lbs, I think the bolts were stressed by someone with an impact. I also found out the rear axle doesn't have drilled hex bolts on the hubs. I'm in desperate need of a source for this bolt. I cannot seem to find anything. In the first picture the zinc coated bolt is all I can find, the bolt on the lift is what I need.
 

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sue

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One of my hub bolts snapped at around 90ft lbs, I think the bolts were stressed by someone with an impact. I also found out the rear axle doesn't have drilled hex bolts on the hubs. I'm in desperate need of a source for this bolt. I cannot seem to find anything. In the first picture the zinc coated bolt is all I can find, the bolt on the lift is what I need.
Aircraft spruce?
 

Guyfang

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Where ever you buy them, you need to tell them what grade bolt you need. Or you will maybe snap another one off. Like Doghead wrote, " Search the nsn?", or part number. That way you KNOW what the grade is, and often can get several other part numbers that will work as alternatives.
 

HDN

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Where ever you buy them, you need to tell them what grade bolt you need. Or you will maybe snap another one off. Like Doghead wrote, " Search the nsn?", or part number. That way you KNOW what the grade is, and often can get several other part numbers that will work as alternatives.
Question: With other projects I've had in the past, if I doubted what grade bolt was required, I would always get grade 8. Is there a case where I wouldn't want the highest grade possible if I had no idea what was from the OEM? The only thing I can think of is the difference between stripping the threads off the bolt or stripping the threads out of the hole.
 

gringeltaube

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Where ever you buy them, you need to tell them what grade bolt you need.
it's a Grade 8 bolt.
Search the nsn?
NSN is 5306-00-930-5248 (part # 10896726-1)
Bolt specs can be seen, here...
(According to that, the head has 2 holes, drilled to Ø 0.120".)

Now, if we go to the parts-TM for the early (gasser) M35 (ORD 9 SNL G-742), it shows a part # 7521631.

NSN and specs, below (this source):

5306-00-752-1631 (68079E, 342B1, 5306007521631) Data
5306-00-752-1631 (5306007521631) NSN Information
NSNFSCNIINItem NameINC
5306-00-752-16315306007521631Bolt, Machine01847
5306-00-752-1631 Features
MRCParameterCharacteristics
AAJDThread Class2A
AAJFThread DirectionRight-hand
AASAThread Length0.828 inches minimum and 0.875 inches maximum
AASBFastener Length1.687 inches minimum and 1.718 inches maximum
AASKHead StyleHexagon
AASUHead Height0.344 inches minimum and 0.375 inches maximum
AATBWidth Between Flats0.750 inches nominal
AHYMNominal Thread Diameter0.500 inches
CBBLFeatures ProvidedFinished head
CMLPThread Quantity per Inch13
MATTMaterialSteel comp 1330 overall or steel comp 4037 overall or steel comp 4130 overall or steel comp 5130 overall or steel comp 8630 overall
MDCLMaterial Document and ClassificationAstm A322 assn std 1ST material response overall or astm A322 assn std 2ND material response overall or astm A322 assn std 3RD material response overall or 66 fed std 4TH material response overall or astm A322 assn std 5TH material response overall or astm A331 assn std 1ST material response overall or astm A331 assn std 2ND material response overall or astm A331 assn std 3RD material response overall or astm A331 assn std 4TH material response overall or astm A331 assn std 5TH material response overall
THSDThread Series DesignatorUNC



No mention of any holes, as one can see.
FWIW, I have a whole box full of those bolts (w/o holes), all are Grade 8 and all came out of trucks from the early 60s and older.
Obviously there has been a change sometime during the late 60s maybe (?), after some engineer decided that that old design wasn't safe enough...
Never found any of them loose, BTW.



Great thread title, btw.
Changed it, already.
 

gringeltaube

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I think the bolts were stressed by someone with an impact.
If that was the case you need 8 bolts, not one...!

Eight new bolts, even non-drilled - but properly torqued (with new lockwashers and maybe some thread locker added), are always better than one new- plus seven old ones, which are questionable, at best... IMHO

Oh, and do NOT use any full thread bolts, there!
 

SCSG-G4

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Oh, and do NOT use any full thread bolts, there!
The reason being, that the full size shank bears directly on the part being held to it's base, which is in rotational stress. Using threaded bolts at that point would allow a rotational movement which eventually would snap off ALL of the bolts at an
inconvenient time.
 

gringeltaube

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The reason being, that the full size shank bears directly on the part being held to it's base, which is in rotational stress. Using threaded bolts at that point would allow a rotational movement which eventually would snap off ALL of the bolts at an
inconvenient time.
Exactly! Thanks Mike for explaining it so clear!
 

sue

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Can’t imagine anyone working on military equipment with out a aircraft spruce catalogue. Any type an, msn bolt,screw,nut, light
bulb etc.
 

Guyfang

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Did they have loctite back in the day? Seems like some red loctite would be a good replacement for the wire? Maybe they went with wire because it wasnt available or wire was just easier to inspect?
This is a very good question. No, no LOCTITE back in the day. Everything needed to be SAFE secured, was safety wired. I still like it better then LOCTITE. And I use LOCTITE, a lot.

I have seen, when working on turbines, times where the fasteners were dirty, holes dirty and oil everyplace, and the LOCTITE did not do its job. You always need to clean the fasteners, before using LOCTITE. Fasteners loosened up. Or they were in a place where if it fell out, bad things happened. LOCTITE can not promise that a fastener will not fall out. Lock wire will.

My mentor, who showed me how to really use lock wire pliers, had hands that looked like he had stuck them in a blender. He told me, "Guy you just ain't never lived, until you have stuck a piece of lock wire through your hand". I laughed. But didn't ever laugh again after sticking some lock wire through the webbing between my thumb and index finger.
 
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