Forging Definitions

[ContractHome]

What is the difference between "bar stock", "forging stock" and "wrought bar"?

and do these definitions change whether the metal is rolled or extruded?

If forged stock is cut and turned down is it still considered forged stock?

 

[metengr]

What is the difference between "bar stock", "forging stock" and "wrought bar"?

Bar stock is a product form - round, square,,,,,. It can be manufactured by rolling, forging, extruding,,,,

Forging stock is a product form, could be plate, bar, etc.,,,, it is forged.

Wrought bar is a product form that has been formed by either rolling, extruding, forging,,,,,,

and do these definitions change whether the metal is rolled or extruded?

See above

If forged stock is cut and turned down is it still considered forged stock?

Yes.

 

[ContractHome]

Is there a difference between round stock and forging stock?

If forging stock is turned down, ground, or milled, then is it still considered forging stock?

Is material considered round stock both before or after grinding, milling or machining if it is round round both before and after?

 

[metengr]

If forging stock is turned down, ground, or milled, then is it still considered forging stock?

Yep.

Is material considered round stock both before or after grinding, milling or machining if it is round round both before and after?

Yep.

 

[ContractHome]

What is the difference between astm A711 and A29?

 

[metengr]

A 711 - Steel for forging stock
A 29 - steel bars, Hot wrought and Cold Finished

 

[ContractHome]

What is the difference in "steel for forging stock" and "steel bars, Hot wrought and Cold Finished"?

 

[metengr]

Here is a tip - review the specifications.

 

[MikeHalloran]

I have no access to the specifications, but just on the basis of the language, I'd urge some caution about confusing "forging stock" and "forged".

Where I'm going with that is that a forged item has been hit with a very big hammer at some point in its gestation. The virtue of forging is that any hidden flaws that are large enough to cause trouble in service will probably be revealed by the forging hammer, which is pretty much guaranteed to turn hidden flaws into visible flaws or outright fractures. Therefore the chance of a "forged" part failing in service is pretty small.

Whereas, steel that has been cast | rolled | hot finished | cold finished, may look perfectly fine, but there is still a finite chance that it contains hidden flaws.

I am guessing that "forging stock" is metal produced by any means and >intended to be forged at some time in the future<, which is probably annealed or alloyed in such a way as to make forging easier, but may still contain hidden flaws. Whereas "forged bar" or "forged bar stock" actually has been under the forging hammer, and is much less likely to contain hidden flaws.

Now that you're thoroughly confused, consult the specifications. ;-)



Mike Halloran
Pembroke Pines, FL, USA

 

[rmw]

Mike, do you literally mean hammer? I always think of a hammer striking something. Forging doesn't always have to be done with a hammer, it can be done with a press, which some might say is just a real slow speed hammer. So some might would say that is the same thing.

Forgings can have hidden flaws and imperfections as some of my past fire drills can attest. Rush heat exchanger delivery schedules wrecked due to forgings that couldn't pass UT due to hidden flaws so new forgings were 'hammered' out and the rest of the Hx just had to wait. Forgings are used for high pressure tubesheets and channels and nozzles.

My only other real up close experience with forgings were howitzer shells made by punch forging. That wasn't a hammer, but it could do more damage than any hammer I ever saw. In went a 6X6X18" red hot billett, down came the ram and out came a heavy wall cylinder that after several other operations including filling it with TNT ended up being fired out of a 155 mm gun. That thing would go through fingers with great ease. Sorry to say I saw that too.

rmw

 

[MikeHalloran]

I literally mean hammer.

Part of my very early youth was spent in a town whose major employer was a forging company. All day long, every few seconds, one of their many hammers dropped. You could literally hear it and feel it, all over town.

I think the forge closed in 2004. It must be a very quiet little town now.




Mike Halloran
Pembroke Pines, FL, USA

 

[rmw]

The forge where the bullets (shells) were forged was one of the loudest places I have ever been in on this earth, but there was nary a hammer to be found outside of a maintenance worker's tool box. Those hydraulic presses were about 4 stories tall and operated at 3000 PSI as I remember it. Nasty, hot, smoky, black everywhere (graphite lube) but no hammers.

Once they lost a hydraulic power unit on one of the press lines and some young crackerjack engineer (not me) suggested that they just gang X number of barrel pumps together in parallel instead, and they did it and it worked until they got the press pumps fixed. Dangest thing you ever saw, dozens of barrels with air operated pumps all going chugh-plop chugh-plop at barrel pump pace. That was loud too. An interesting HR observation made was that a certain group of workers couldn't be assigned to work near the barrels because all they wanted to do was dance in time with the pump strokes. True story. They had to find workers that didn't have 'rhythm' for that area.

The forge where the tubesheets and pillboxes were made (the occasion of my visit was to examine a forging that had failed UT that was a pillbox) was all presses, and was relatively quiet by comparison.

rmw

 

[MikeHalloran]

Sounds like a fun place.


Mike Halloran
Pembroke Pines, FL, USA

 

[rmw]

Well, more to the OP's question, the bullets started as pretty rough looking unfinished forgings and were rough machined, formed, heat treated, finish machined, threaded, painted and still went out the door as forgings (to be filled with TNT and ultimately destroyed).

The pillbox and tubesheet forgings were just that; forgings but they had been machined on every surface at the forge. They had to do that just to be able to UT them. Upon receipt by the Hx Mfg'r they were further machined, drilled, overlayed, as they became part of the heart and soul of a Hx but they never lost their identity as A350 LF2 forged material.

rmw

 

[SnTMan]

To further muddy up, flange rings and etc. are usually ROLL forged. This is pretty quiet, compared

Regards,

Mike

 

[ContractHome]

Is forging stock that is used for/prior to forging, or is forging stock material that is ideal for forging and has already been forged?

 

[swall]

"Forging stock" means the billet or bar material prior to going to the forging press.

 

[unclesyd]

Here is a pdf that covers nearly all the basic forging terms. There are a lot of special terms for specific operations used by the shops that don't get published. Nearly every time I visited a forge shop I would hear a new one. The basic terms did allow me to converse with the forging people intelligently. If you are no sure about a specific term or terminology look it up by a search.

http://ajaxring.com/docs/glossary.pdf

 

[stanweld]

unclesyd,
Did you find it odd that "burst" was not listed nad defined?

 

[unclesyd]

I think the omission of burst is an error as it is a very common term used by forgers. I've heard it more from the blacksmiths than I have any of th other branches.
I haven't found a list that sorta kinda breaks down hammers, like a gravity, gravity assisted, and various trip hammers. This omission of certain words is why I but the recommendation to look up terms not covered.

Addenda:
Back in my pup days the company I worked fro had a contest as to who could get the hammer closest to an egg on the anvil for a prize of $10.00 and a day off. By pure luck I beat out about twenty grizzled veterans with a distance of around 0.001 and 0.002". I was cock of the walk for a while. I never had to backup my feat as Uncle Sam sent me draft notice.