Bolt with "10" on the head
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Todd727
Gold Member
Or get one of these to hang next to your bolt trays:
Nut & Bolt Thread Checker (Inch & Metric) - Tap And Die Sets - Amazon.com
Nut & Bolt Thread Checker (Inch & Metric) - Tap And Die Sets - Amazon.com
scdeerslayer
Gold Member
Great, another item added to my Amazon Wish List (to buy list) because of this site.
dickfoster
Elite Member
That is a metric marking for metric common high strength metric bolts which are similar to SAE grade 8 only a bit stronger than grade 8 hardware. You can get them most any place that carries metric hardware like TSC for example. Just match the length, thread pitch and strength. Good luck getting out the broken ones because those suckers are hard.
OP
POC
Gold Member
Actually found 4 broken bolts. 3 of them came out easily (maybe part of the problem?) The other 1 is being a big pain. It is the one in the "reamer bolt" hole. Had to get a tougher drill bit, will try again this weekend.
dragoneggs
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Cat bolts (grade 8) aren't really the 'King' of bolts but for most all industrial/commercial applications they are. For comparison, Grade 5 is a 120ksi ultimate tensile strength and a Grade 8 is 150ksi. Now the King of bolts are found in the aerospace industry. Not really uncommon to find 220ksi bolts! That said, these high strength bolts are very expensive and are relatively brittle compared to lower grades and as such are not used much if at all outside the aerospace industry. Sorry if I went off on a tangent here but just wanted to spread some uncommon knowledge.
olPete
Gold Member
Wow. 4 broken? Were they all in the same area/same side?
Yep those hardened bolts are murder on drills. Just keep to low speed if you can. Have you been in touch with the dealer about it? Definitely get a paper trail behind you, if you haven't.
OP
POC
Gold Member
All on the same side. Dealer went out of business.
olPete
Gold Member
Would your tractor still be under factory warranty? If so, get the next closest one involved/informed of what's happened. Take heaps of photos just in case there's further issue with that hub in the future. Not saying there will be issues, but that is extremely unusual for so many bolts to be broken and missing on one assembly. It most likely has just been a torquing problem is my view, and as they've gone west the strain has gone up on the remaining bolts. So pleased you found it when you did.
sixdogs
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The CAT bolts I am familiar with are far in excess of grade 8 I believe and are as tough as I'm familiar with. I've seen $10-$15 bolts. CAT may carry grade 8 or use them in a lot of applications or sell in a counter rack but they primarily use/carry/stock some sort of alloy or extra heat treated bolt for use in CAT severe applications and are very expensive. For example, bolts for dozer tracks would have to be much stronger or harder than grade 8. Aerospace bolts are one offs that aren't likely to find their way into the industrial market although I think I have seen some auction off at a gov't surplus sale.
Related to this, I had a log winch from Norway once that came with a couple of alloy log chains. They were about four times the price of grade 70 chain but were as tough as they come. If I can ever buy alloy anything in hardware or related that's alloy and heat treated I buy it.
Related to this, I had a log winch from Norway once that came with a couple of alloy log chains. They were about four times the price of grade 70 chain but were as tough as they come. If I can ever buy alloy anything in hardware or related that's alloy and heat treated I buy it.
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npalen
Elite Member
Very important to torque bolts especially the high strength variety. The bolt must be stretched into its elastic state to hold properly and not break due to constant flexing.
sixdogs
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Very true. Also LocTite those kin dof bolts because they are subject to so much vibration. Blue--medium LocTite is sufficient. I used to be plagued by loose bolts that worked loose until I started to LocTite most everything. Now, not a loose bolt I can rememeber. None on lug nuts, however.
dragoneggs
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Yep agreed... often the reason is to keep the structure in tension throughout the stress cycle vs. letting it go into a compressive state. By doing this, you increase the fatigue life significantly.
I am a big fan of blue LocTite especially on cheap bolt/nut combos that typically come in a DIY put together assemblies of whatever. The tolerances and QA of the low quality threads back out much more easily than tightly controlled fasteners when subjected to vibration.
jbwilson
Silver Member
My guess is that it is simply means a 10mm bolt of indeterminate grade mfg somewhere in a jungle clearing in Asia. Doubt that a bolt of that size (and purpose) would have been manufactured to meet some amazing standard. The fact that some bolts loosened out indicates to me that the tractor mfg didn't apply standards akin to constructing space rockets.
