I believe these dies were used by wheel wrights and makers of farm equipment. They had their own handles that look like a combination of current die holders and the old monkey wrench for square nuts. archive.org/details/UnionTwistDrillCoCatalogOfTapsDiesReamers1948 page 81 they were still selling these dies in 1948. I would guess their use would be where it was difficult to keep a round die from spinning in the holder.

Hi,I'm Paul from Boston England and I'm a 4th generation motor trade member and as the guy said below my great grandad had die sets like these and he was a coach builder and wheelwright, we see these all over the place in the uk, quality varies massively but in those days you paid what you had to for the work you got!! We call them die heads or stock! Don't ask I never asked why they call them stocks myself! They are usually whitworth (course thread) they also do a w/worth Fine thread which changed over time into BSF (British Standard Fine thread) the holders were like the USA two piece die holders but used the square die head only and over time we changed the shape to a octagonal one, the squares and octagonal tended to bu used to repair worn or damaged threads and the split dies were used to cut new threads once we had the quality of metal better! People put old ex military boxed sets on eBay even if not all parts were there,and think that ex military or mod/ s ( ministry of defence/supply) is a reason to ask silly prices . if you might need this sort of threads and see a decent part set cheap buy them but if it's silly money get 1 tap or die at a time from the sales site I said earlier, some of the dies/taps are crap and die real fast but a set or parts from a good English Or American Maker should last well of if you want to do a lot of w/w work buy the later ex army/ government contractors more modern split round dies and taps much over here at car boot sales and auctions can be good metal or even HSS, just remember as a guide if you want a tap or die the size refers to the diameter of the bolt/hole not the nut/bolt head we here never use these anymore unless it's a old repair etc.but there's tons of this stuff everywhere, and village garden sales and even junk shops can do a bargain if you look hard well I've gone on for too long so I will just say stay safe when your working and keep on bringing on the weird tools!!!all the best from paul

As mentioned they appear to be Warragul Dies usually used on pipe threads they are still available today. Look up warriguI dies at Blackwoods Australia. I have the ones my great uncle George had. I have two holders for the dies. I have used them for cutting tapered pipe threads. All of mine are bsp, British Standard Pipe threads.

Looks like a real old UNC set. They used square dies in square die holders back then, same as the round sets commonly used today. Antique. The square design makes more sense as it doesn't require a locking pin as with round, butthe frame has to be stronger/heavier. They are still available today, useful for high torque work, but more expensive to produce as they contain a lot more metal. Just another way of doing it. Cheers Rob

Rich, thanks to the wild world of KZfaq algorithms I've found you. I actually work at this very plant, though it is no longer Butterfield. I have never come across a square die, but when I return to work on Monday I'll look to speak with some of our experienced crew and see if they can recall these. I hope to have an answer back to you soon! Very cool, thank you for sharing.

The square dies were common with blacksmiths in the 1800's among others.... its rare to have a full set like that.

I've got a stack of them held together with a looong carriage bolt, got them at a garage sale, appear to be inserted with some sort of steel in an iron body they seem to work fine as any other, so I use them as intended...

Dies used for cleaning up existing threads. Square dies are still made today, but the Butterfield Derby Line dies were originally used to clean up threads on buggy axles.

I think they are designed for cutting external threads on pipe and larger diameter round stock. Square shape just allows them to be easily turned with high torque. Still available in Aus - try googling 'Warragul Die'

Butterfield made a great quality product. I have many of their tap sets given to me by a friend. I don't think they were handle mounted as I see no marks from a retainer or fastener so my thoughts are they were vise mounted and the workpiece turned into them. Most likely by a blacksmith. Wonderful pieces bud. You will have to let us know what you find out about them.

As far as I know, these were a design that was specific to Union-Butterfield, who were known for making very high quality cutters. I think Sandvik now own the brand name. Although other manufacturers copied the design later. These were originally made back in the 1880's when they were used in the manufacture of Railway Locomotives and equipment as well as in the manufacture of Carriages and Wagons. They have a specific die holder that holds them.... looks like a modern die holder but is is a kind of diamond shape in the centre. They were propitiatory to Union-Butterfield to encourage people to only use their dies. The reason you would find references to Blacksmithing is that a lot of Railway shop work involved heavy forging and blacksmithing work. You may also be correct that they may have been used in screw making as a lot of that went on in Railway workshops. They made almost everything they used in house.

When I was younger by almost 22 years I worked at a factory that built satellite dishes. (Before the small ones). In the machine shop they used something similar to turn out the bolts for the pitch adjuster. It started as a piece if 3/3 bar stock. The machine used was a dedicated machine. Turning the threads was it's on my purpose. A square die like that was used. I remember this sure to I had to fire a "machinist" for ruining the die. He didn't know there was supposed to be cooling/cutting oil. The die cost the company upwards of 1000$. Or so we was told. The company was new tech of Bonnieville. It was located in Bonnieville Kentucky. They also made tool boxes and cookware.

Cool I've never seen those before. They might be worth keeping for chasing damaged threads if you find/make a wrench big enough for them. Possibly even to debur lathe cut threads. 5/8-11 is pretty common in some industries I tap/threadmill it fairly often.

They were used by blacksmiths machinests ,and pipefiters and are still used today by thous that have them. I have a set that I still use. they have a handle that holds the dye on one side and holds interchangable guide bushings on the other side. It had two handles the same as modern dye holders.

Hey Richard, I have no answer to your question so I apologize in advance. However, seeing your square dies reminds me that old time watch makers used a similar method for threading. They used a single plate with several different dies formed in it to make very small screw threads. Not related I guess, but interesting nonetheless. Thanks for showing them. Apparently, these are still sold, but I am unable to post links in the comment. Will email them to you. Joe

They are just what dies used to be . Somewhere out in the shop I have most of a set strung on a wire along with the handle for them that my Grandfather had and used on the farm pre ww2. Funny how an old square headed bolt or nut is unremarkable but a tool having a different and simpler to make shape seems a mystery LOL

Pretty sure they are just old farm tools, I find them in just about every old barn clean-out. There are handles to hold the dies, I saved a bunch from the scrap bin thinking someone would want them, but they do not sell well. Might have a handle or 2 still kicking around if you want one.

Lots Of Good Answers ...........I Do Not Have A Clue ! But You Got A Square Deal ................

Hi,just in case anyone's interested, I checked my old tool catalogues and a 1951 T C Jones cat. Lists them for sale as Stocks for tube & conduit threading! Only they were sold loose with no option for a boxed set? Regards paul

Not a clue but cool looking

My Dad has several old pipe dies that are square like that. I'd check Ebay for a die stock that fits if you want to use them. Those dies are probably close to 80 years old and may even be for sharp V threads.

There pretty old but I believe they were a lot like what we have for hex dies today. They were meant for cleaning up existing threads if damaged and not for forming threads from scratch. In a pinch even a pipe wrench could be used to turn the die if no die stocks were handy. I do recall seeing die stocks listed for those large square dies in a real old tool catalog. Who knows, you might get lucky finding a couple of the stocks on Ebay by setting up a daily search. Maybe check the taper angle on the threads against a more normal die? A longer and slower angle should indicate there for repairing threads not making them.

Richard, I can’t say what yours were for, but I have a set of square pipe dies that look very simillar

G’day Richard, I have a stock to hold those die’s and a single 3/4” pipe thread die handed down from my father, I was/am the only one in the family with gal water pipes. If I recall correctly they also were for the onsite

The butter field railroad machine shop maybe.

Hey, got a ton of these and the hadle for them too. Can put a lot of torque on one of these before they brake vs the "modern" round ones

I've seen them before. Check out acorn dies for some really weird stuff. I think this is what as made before there were popular standards of round die sizes. Bunch of them listed one bay right now. I think they may have been turned with a wrench. I don't remember ever seeing a die stock for big ones like this.

they’re pre-run sample sets the manufacturer makes. they get the okay and then they build the part to that spec.

I can't help but I would assume they are just standard dies only with square bodies. Possibly they were for a screw machine type application.

I have seen a ton of those in my day, Never bought or kept any . I bet they are used for farm and like wheel and big heavy repairs ..

These go a way back!

It seems that these were made back in the time when thread standardization was being developed. Shop made dies could be made on a lathe and would be perfetly centered if not removed from the headstock. Manufactured dies closely resembled the hand made dies of the time. At least the story sounds reasonable. chestofbooks.com/crafts/machinery/Shop-Practice-V1/Tool-Making-Part-II-Standard-Tools-Thread-Cutting-Dies.html

They are called Block Dies. The ones I used were for pipe threading. you can get new ones here. www.reedmfgco.com/en/

my guess would be they are meant to be used in a vise ,you may have to make a square 2 handled holder for them ,that's what I would do .

There square to start with your hand and then the special wrench which is a square with two handles like a round die handle

The 2 1/2" dies are the smaller set, I have 2 antique Tap wrenches, 1 for 2 1/2 square and 1 for 3" or 3 1/4, I'll have to go look. I'll throw up a quick vid in the next few days to show them off.

I actually have a die tee holder for those dies. I don't see a name on it buyy it looks like it is for 2.5 inch square dies. I can send you a picture if you wish.

I was still able to buy them in 1985.

I don't think they were meant to be used in a machine but by hand with a handle or in a vise.

make a square die holder with a handle like i did with a big set i have.

Look up Reed Die Pipe Threaders

There are special die holders for those

Hello friend these are Pipe dies and went into a square die holder with a ratchet mechanism and replaceable guide bushings,- here is a version of the die holder - happy to email you photos if you send me an email address. Regards

Reed makes a square die handle that would work. Are the dies Standard Imperial or NPT? Check out laurelleaffarm.com, they have/had a vintage Reed square die handle.

hey man i while back i made a mistake and removed your post . total bozo moment on my part i was trying to pin it and hit the wrong thing and there is no way to undo it that i know of . and i didn't know who's post it was tell a few days ago i saw you sent a message asking why it happened (my bad this was all moths ago man and just saw this). i replied but the you tube message system is not something that gets noticed much lol. hope you see this here