Old Cat bolts

could be a couple of thing like the bolt has been replaced with a metric head bolt - I have got some on my D2 like that or most likely they are worn off especially if they are around the track areas. Again this is typical of rust or abrasion impacts on the bolt head. I think if you can get them undone, it is a bonus, and never mind the shape of the head or Cat emblem!

Pretty common in Australia. Some bush mechanic has used whitworth 3/8 bolts. They will screw in but thread angle is 5 deg different.
Throw them over your shoulder and get new unc bolts with 9/16 heads.

[quote="wimmera farmer"]Pretty common in Australia. Some bush mechanic has used whitworth 3/8 bolts. They will screw in but thread angle is 5 deg different.
Throw them over your shoulder and get new unc bolts with 9/16 heads.[/quote]

your onto that wim farmer I agree with everything you said and your solution 👍

Paul

I hate to tell you this.
international used those kind of bolts with the dimple in the center on the old 35's and 40's. looks like someone has upgraded the fasteners on your 2.

Didn't International use unified threads, the same as Caterpillar, in which case, the standard 9/16 spanner would still fit.

Hi Shane,
a 5/16" Whitworth spanner fits a bolt head that is 15mm across the flats.
Some time ago in past history, for War economy of metals, the real 3/8" WW head sizes were reduced one size down for smaller heads and nut sizes. Hence the confusion about a 5/16" WW spanner fitting a 3/8" shank bolt.
Google should find a better explanation than mine.

http://www.sat.dundee.ac.uk/psc/spanner_jaw.html

Cheers,
Eddie B.

[quote="edb"]Hi Shane,
a 5/16" Whitworth spanner fits a bolt head that is 15mm across the flats.
Some time ago in past history, for War economy of metals, the real 3/8" WW head sizes were reduced one size down for smaller heads and nut sizes. Hence the confusion about a 5/16" WW spanner fitting a 3/8" shank bolt.
Google should find a better explanation than mine.

http://www.sat.dundee.ac.uk/psc/spanner_jaw.html

Cheers,
Eddie B.[/quote]

I have never heard of that before but as with most things Im still learning

Paul

I reckon it was only 15 years ago that whitworth was the most common bolt used in Australia maybe not in machines but in just about every other thing sheds buildings fences just about anything we built

Cheers all. So when did Cat start using/making there own bolts?
SJS

As far back as I'm aware of, Cat used their own bolts with their own markings but as far as who actually made them I can't say. Could've been Cat themselves or also very possibly an outside manufacturer that made the hardware to Cat's specifications according to the different areas in which they were to be used.

I took a couple minutes to dig through my old Cat bolt cans to show three examples of bolts that would be found on most of the vintage equipment that is discussed on here -


[img]http://i802.photobucket.com/albums/yy310/TRNelson/photo1_zpscd1c1d36.jpg[/img]


The first bolt with the big "C" on the head is an early Caterpillar bolt that is found on many of the machines built from the tail end of the 1920's up until the early-to-mid 1930's, approximately.

The middle bolt with the clearly defined circle around the perimeter and the "CLN" code inside of it is typical of the style that was used on the machines built during your "J" model D2's era, approximately from the mid-to-late 1930's up to the later 1940's.

The last bolt with just the "CLU" code on the head is typical of what is found on the Cat machines built from the tail end of the 1940's up through the 1950's, and perhaps even later than that but I don't personally know how long that style was used before the appearance changed again. I just know that my 1950's era D2's have those types and they are the newest Cat machines I've ever owned.

Another thing worth noting is that those letter codes you see on these bolts (like the "CLN" and "CLU") supposedly mean something in relation to the specification of the bolts, although I personally don't have the specifics of that information. There are other number codes that can be found on both of those styles of Cat bolts from those time periods too, so don't be surprised if you run across a few other combinations of letters on them as well. Perhaps somebody else on here has better information on what those codes mean that they could share.

On a related note, every time I've ever dismantled an old Cat wreck for parts or scrap, I've always scavenged all the good original Cat bolts, nuts, or studs that I could get off of it for possible future projects. I'm just one of those people who are fussy that way, I like having all the original fasteners not only for the authentic look, but for the quality as well. I usually end up digging through my many cans of Cat hardware at least once every time I fix something on one of my old machines.