4 inch diameter bolts

I saw some studs on a natural gas pumping engine that were about that size, it was a V4. Pistons about the size of trash cans.

Stan

I got a tour of the engine room of a big new Hyundai Industries container ship last year. I didn't actually see one out but bolts holding the engine to the bed had heads a good 6" diameter. Also the big trucks they use out at the chalk mines east of me are held together with some pretty darn big screws. :-)

I haven't seen 4" but I've seen somewhere around 3"

They were the bolts holding down a housing in which spun a 250 lb. blade for chopping up plastic prior to recycling.

The blade ran at a few hundred RPM and let me tell you... If anything fell in there, it was gone. It was an open hopper system where people threw plastic in by hand too. Back in the late 70's... I'm sure OSHA would LOVE to see a plant like that now.

The same place had an 8' wide gillutine for chopping up full 4' X 4' or larger boxes of plastic that were filled when molten - i.e. solid cubes. It had a dual stage ram that was capable of cutting just about anything I threw (er... anyone else I mean) in there to test it.

Sure wish I had photos.

Regards, Joe Agro, Jr. (800) 871-5022

Coincidentally, I have a shiny new 4-4 UNS tap sitting on the back corner of my desk. It came in an bankruptcy auction lot from a machinery builder, part of the fiasco that closed Bridgeport down for a while.

Two places I've seen threads this large, and larger, are on the tie rods of presses and injection molding machines. There's often a hydraulic nut on one end of the rod. Like so...

I seem to recall that the bolts that hold the Space Needle to it's foundation are about 4". Anyone taken a look lately?

So the obvious question (to me, anyway) is who can Iggy sell these to and what are they worth?

Perhaps people that repair / overhaul smallish 4 - post punch presses.

The REALLY big presses, 2000 ton capacity range, have 4 tie rods the size of telephone poles. I've seen 8" dia studs, 8 of them, holding the two clamshell halves together for hydraulic turbine butterfly valves. These were 5 meter in dia. and operated at around 600 psi IIRC. Tightening these was a REAL problem, NOT that it had to be....

Wolfgang

Dave H> > That's a fairly small tap for the main tie bolts on a press. My local

That's a great guess, I think that these ones are used mostly for presses etc. Thanks to you and others. For some reason, I have accumulated a little tap collection of various interesting taps (to which these huge taps would not be a part), but I did not know why would people need the big taps like that.

When you visit Kennedy Space Center, there's a talk you can attend about the Shuttle. The Shuttle is held to the pad by 8 bolts, 4 around the base of each SRB.

These bolts are 28" long and 3.5" in diameter, and weigh something like

The threads are VERY sharp too, so they don't let you handle it.

-gc

Saw quite a few cap nuts for (as I remember it) 6 inch threads. the gentelman who had these told me they were from the "bolts" that were used in a power plant to hold the steam boiler together or some such. He was an "operator" or something like that in a local coal fired plant. I may even have one of them back in PA in a barn on the property I have back there. I guess I'd call them a cap nut since the threaded holes don't go all the way through. The back end is a very large hex though not a dome. ...lew...

Why were the threads so sharp? ERS

Damn if I know. I guess they wanted to show off their precision threadcutting machine? It looked like the bolts were machined instead of being made with a die, to my totally amateur eye.

Now that I think about it, I thought all large threaded items were machined, so I didn't think there'd be taps/dies this large.

Hey look... the sig-monster has learned to read...

-gc

Ever been on a deep sea oil rig ? - platform I mean ? - Some stuff has to be bolted - like buildings and cranes. Think of a heavy crane that brings 'stuff' - like stem tubes to the site - and food... people... There are some really big things out there - like big Earth moving or scooping machines...

Martin

Martin H. Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH & Endowment Member NRA Second Amendment Task Force Charter Founder IHMSA and NRA Metallic Silhouette maker & member

Ignoramus29862 wrote:

machines...

I figure that a 4" bolt at 50000 PSI could hold about 480,000 lbs or about 218 tons.

Here's a picture of that tap:

It's not likely that the taps where ever used to actually tap a thread this size. I imagine they're mostly used to clean up damaged threads in a nut. The amount of force needed to turn a tap this size for cutting threads is pretty high.

Maybe it was just made as a display of metalworking skill without any intended use,

The threads were sharp because they didn't deburr them.

John

I was down in Florida in about 1978 with a buddy. We were just out of high scholl looking for adventures and girls. We were driving his Vega wagon all the way from Michigan. I love space travel and rockets and stuff so we stopped for the grand tour of the space center. They took us out on the shuttle runway and to all the huge buildings and displays. I loved it but it wasn't quite enough. There is some kind of wilderness around there, marshlands so we drove out thru this massive field, birds and even a cougar crossed our path. Narrow road and about 50 feet ahead of us it just paused then moved on. I don't really think we were supposed to be driving around out there.