Question about vintage bolt

The 10 and 15 had bolts that were marked with a C. They were centered in the head of the bolt. The 22 bolts were no longer marked with the C. I don't know about your bolts. - Wally

My Sixty has some “C” bolts as well. I assume they are Cat, but stand to be corrected.

Might stand for Chicago Nut & Bolt Co. , not sure. Maybe they didnt exist that far back.

They were removed from the LeT clutches, so 1944? They do have the thicker head like the Cat bolts, but that might have been more common back then.

There are some on my 30 with the thicker head and the C off center and a few with the C centered but still with the heavy head.

Ok guys, thanks for the input . I will save them with a question mark on the bag.

Just looks like the stamping on the C is off center a bit, guessing they were a Cat bolt. Imagine at sometime they were in the parts bins as bolts and could have made an appearance later. As the early tractors had them most I have seen were on center with a C. Tho I will say I have an early Cat tractor and I have not found any bolts with a C on them as possibly at somepoint there was an issue with them getting to the plant. I can not believe someone has torn down beyond what I have torn down so guessing at some point there was void in on hand quantities of Cat marked bolts. Some of the bolts I have found even lack a decent finish on the head as they were produced on a lathe with all the tool marking obvious from production.

Generally, the letter markings on the heads of bolts are the manufacturing companys markings.
Cat bolts are readily identified by their thicker heads, that are non-compliant with SAE fastener standards.
I have never come across any other manufacturer except Cat, that produces the thicker-than-standard, regular bolt heads.

Here is a link to manufacturer identification marks on fastener heads. However, it is a 2008 document, so it may not include many earlier fastener manufacturers.

Illinois DOT - Fastener identification guide

I seem to vaguely recall seeing the "C" mark on early RD model Cat fasteners. I'll check on my collection of old Cat fasteners tomorrow, to see what I can find.

[quote="OzDozer"]Generally, the letter markings on the heads of bolts are the manufacturing companys markings.
Cat bolts are readily identified by their thicker heads, that are non-compliant with SAE fastener standards.
I have never come across any other manufacturer except Cat, that produces the thicker-than-standard, regular bolt heads.

Here is a link to manufacturer identification marks on fastener heads. However, it is a 2008 document, so it may not include many earlier fastener manufacturers.

Illinois DOT - Fastener identification guide

I seem to vaguely recall seeing the "C" mark on early RD model Cat fasteners. I'll check on my collection of old Cat fasteners tomorrow, to see what I can find.[/quote]

I know there are bolt mfg. that make thicker heads in 1965 when I was purchasing for a const. company. Lawson high quality?? but they had standard grade 8 markings.