Bolt with "10" on the head

[Todd727]

http://www.lippincottsupply.com/bolt-nut_ident.pdf

 

[POC]

View attachment 498631

http://www.lippincottsupply.com/bolt-nut_ident.pdf

My bolt doesn't look like any of those.

 

[flyerdan]

I seem to recall seeing bolts with a 10 cast in the head on a Blazer I was taking apart, thought it was an inhouse GM thing. Is is possible that the bolts were replaced sometime before you got the tractor, or did it come new that way?

 

[POC]

I seem to recall seeing bolts with a 10 cast in the head on a Blazer I was taking apart, thought it was an inhouse GM thing. Is is possible that the bolts were replaced sometime before you got the tractor, or did it come new that way?

I bought new from the dealer.

 

[PhysAssist]

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.

Interesting you mention the increasingly brittle character of harder bolts- my machinist/welder friend told me to only use Grade 5 bolts on my snow plow and other implements, because they'll bend before breaking, giving me a fudge factor before things shear off.

 

[olPete]

Interesting you mention the increasingly brittle character of harder bolts- my machinist/welder friend told me to only use Grade 5 bolts on my snow plow and other implements, because they'll bend before breaking, giving me a fudge factor before things shear off.

I have pinged the odd high tensile one while welding near them with gas, as the guys above have mentioned they are usually well torqued up to get the stretch.. obviously the heat of a gas torch is enough to expand the metal around them faster or more than they can expand. And then they are a #### to drill into to extract! Most all of my stuff runs metric bolts, and without having grade 8 to compare to, you wouldn't want anything harder to drill with my bit set!! Even the metric '8s' are very hard. Occasionally bust one on my MX bike and have to ez-out them.
You are dead right, I think that's why the Japanese especially have put numbers on the higher grade ones, so you don't put "butter bolts" in HT places, and vice versa.