

Great find; don't recall seeing that handle grip pattern before on any tool - thanks for the thorough pictures.McKaig-Hatch #86 Arc Joint pliers. Just picked them up.
"If you don't know it then just wang it."eBay LOL. Well, I’ve heard of Buster Hyman….”Morris”?..Not so much.

So each handle seems to have a number forged into it. Arguably 5145 and 8640, is that what you're seeing? Anyway, they could be something else S145 and 864D or whatever but if they are 5145 and 8640.....different steel alloys on the same pliers?McKaig-Hatch #86 Arc Joint pliers. Just picked them up.
I’m thinking 5145 & 8840. Don’t know anything more about why the 2 numbers.So each handle seems to have a number forged into it. Arguably 5145 and 8640, is that what you're seeing? Anyway, they could be something else S145 and 864D or whatever but if they are 5145 and 8640.....different steel alloys on the same pliers?
OK, well "8840" wouldn't work with my alloy theory. BTW, there is a precedent for M-H ID'ing the alloy used.I’m thinking 5145 & 8840. Don’t know anything more about why the 2 numbers.
I took a 2nd look and it could be 8640…OK, well "8840" wouldn't work with my alloy theory. BTW, there is a precedent for M-H ID'ing the alloy used.
Odd, for sure, but at least they're not on the same contiguous piece of steel, which would make no sense whatsoever.if they are 5145 and 8640.....different steel alloys on the same pliers?
It’ll be interesting to see if members also have the arc joint pliers and see if the numbers are the same as ours on the handles…Odd, for sure, but at least they're not on the same contiguous piece of steel, which would make no sense whatsoever.
It seems crazy, and could just be a matter of using old stock handles from two different batches, assembled together incongruously to each other. In other words, maybe there are M-H pliers out there with '8640' or '5145' on both handles.
Or, maybe these were both made with '8640' or '5145' handles originally and mixed up later.
Seems highly implausible, though.
What's intriguing is that on both sets of pliers, the handle made from AISI 8640 steel is the handle with the long arc-jointed slot in it and the handle made from AISI 5145 steel is the handle with just the pivot pin hole in it.
AISI 8640 is a triple alloy composition made with low doses of Nickel, Chromium, and Molybdenum invented as one of several "New Emergency" 86xx/87xx steels by a WPB-Industry consortium in late 1941 and early 1942.
AISI 5140 is a high content chromium steel that does not jibe with WPB WWII alloy restrictions.
I am suggesting - as complex, nerdy, and over-engineered as it may seem, that perhaps M-H deliberately made each handle out of a different steel composition due to the different respective purposes of each handle.
Consistently, it's the same handle as yours and Don's.the 5145 is on the one handle
Not seen this handle grip pattern until Ayrhead’s above, now yours; same deeper/heavier transverse indexing/lines at the rear.
Forgot about that. That was a pretty good one.@Ayrhead
For a little twist on the pliers with two different numbers and my theory about two different handles and two different intentional steel compositions, note that we have seen another M-H tool with two different numbers on it, both of which are also numbers for two different AISI steel compositions. In that case, it was a combination wrench, which would seem to eliminate the theory. Further eliminating it was one of the numbers being similar in format and series (15xx) to M-H part numbers. But in your case (the "86") - and in the case of a third tool, also a wrench, owned by me, the tool clearly has a part number, casting doubt on one of the other numbers that seems to be AISI numbers being a part number, because two part numbers is just as befuddling as two AISI numbers. You can read more on that and see the tools I am referencing here. @MR.X was also involved in that discussion.
Me too, until this morning, revisiting the topic with a fresh invigorating cup of bold strong coffee.Forgot about that.
It was.That was a pretty good one.
...the grip pattern on my No. 438 slip joints is different than the grip pattern on the No. 86 arc-joints that Don and Ayrhead have posted, even though all three pliers share the same era monograph logo.Way upthread I posted Model No. 438 8" slip-joints with the same M-H logo as the logo on the water pump pliers that @Ayrhead and @d42jeep have posted, but it has a completely different grip pattern...[ ]...Linked here.



I really enjoy the intermingling of the minds from everyone when we’re all trying to to figure out these little mysteries…As I mentioned here...
...the grip pattern on my No. 438 slip joints is different than the grip pattern on the No. 86 arc-joints that Don and Ayrhead have posted, even though all three pliers share the same era monograph logo.
For comparison, here is the grip pattern again...
...and here is the rendering of the grip pattern in the 1954 catalog...
It's not exactly the same, but very similar, with stacked different length lines bracketing chevrons (three on the tool, two in the catalog image of the tool) in the middle. Not to put too fine of a point on it, but the grip pattern on my example of the slip-joint pliers and the grip pattern shown in the 1945 image of the slip-joint pliers are much more similar to each other than they are to the grip pattern on the arc-joint examples.
If you go into the catalog, it's obvious that they put the same grip pattern on the economy slip-joints and the thin-nose slip-joints.
Unfortunately, they don't show the grip pattern for the arc-joints.






X, this is from the other thread, but putting it here. I see THIS 5/8 combo wrench that Gerald posted on Sep 24, 2024, but it has no 1555 P/N. Do you remember where he posted another example with the 1555 P/N? (Don't kill yourself finding it if you can't. @Mintgrun has a 1552 upthread here that also helps establish the heretofore undocumented Combo wrench series you (and then @four.cycle) sussed out on the other thread.)....and a 1555 5/8 combo on the "progress is fine..." blog.
...that @wrench136 found and posted a couple years ago!...nice boxed set.

Went back to your link; after you displayed the Dunlap handle grip patterns, found this image from a pair of Dunlap s/j pliersAs part of this discussion you might find it interesting to check out the Craftsman Circle Y thread.
Sears was buying from McKaig hatch as a supplier of Dunlap and Craftsman tools.Craftsman Circle Y Tools
A little gathering of Craftsman with the Y in a circle marking. Pardon my rust. Let’s see what else is out there.www.garagejournal.com
Some Dunlap slip joint pliers with the same handle pattern.
-Don
Another scenario to consider is:McKaig-Hatch #86 Arc Joint pliers. Just picked them up.
It’s a possibility…Another scenario to consider is:
Your assembling pliers in Archibald McKaig Jr.’s factory and the Scottish air of frugality permeates the whole plant.
You have bin/box/tote each of right and left handles; one box empties and you have 11 left in the other; the last of that production run - you reach the ‘waste not-want moment’, there’s a bin of the next lot, remember a penny then was worth today’s quarter - no problem; they go on down the line; and your thinking, wait till somebody comes across these guys !!!
Another scenario to consider...
Agreed. And that's the possibility I described in reply to you here...It’s a possibility…
I think it would be more plausible if the numbers were part or sub-assembly numbers. We HAVE seen that with handle halves on Crescent and other pliers....could just be a matter of using old stock handles from two different batches, assembled together incongruously to each other. In other words, maybe there are M-H pliers out there with '8640' or '5145' on both handles.
I don’t really see an issue; Great Depression mentality in a Scotsman's factory - throwing perfectly good product in the scrap; no way.Agreed. And that's the possibility I described in reply to you here...
I think it would be more plausible if the numbers were part or sub-assembly numbers. We HAVE seen that with handle halves on Crescent and other pliers.
The coincidence of them being AISI numbers is one major source of doubt for me. It would be very odd to have a batch of plier parts made out of 5145 steel laying around long enough for them to be mixed in with pliers made out of 8640 steel or vice versa. These compositional changes usually occurred across time. Another steel choice is price point, but that's usually carbon vs any high end alloy steel. In this case, we have two alloys. I don't know that they'd be near the same line.
The other cause of doubt about this is my observation about the consistency. If all 5145 handles are the pivot hole handle and all 8640 handles are the handle with the arc-joints notched in it, the guy on the line reaching into an empty bin could not simply reach into the bin that has some handles in it to put two 5145 handles or two 8640s together to make a plier. So far, we have still not seen an example in which the numbers are interchangeable.


Welcome to GJ. That's a nice find anywhere on the planet but I'd love to know the story on how it made its way to Germany!Guten Tag,
Ich besitze dieses wunderschöne Set.
Sehr gut erhalten.
aus Deutschland