OT -kinda. How are cast iron pipe fittings manufactured?

I have more than a casual interest in the process of casting iron. I recently purchased a 3/4” cast iron pipe plug. So what, right? Well, what struck me was how crisply cast this part was—-see the embedded photo. Obviously they are pumped out in huge quantities and in great variety on a daily basis. So, any attention to detail on individual pieces is impractical. This part seemed to be sand cast based on its surface texture, but I am not sure about that. Also obviously, it was made in China.

I looked on the Web for videos or descriptions of how these parts were made, but found practically nothing. Does anyone have information about this? Maybe a video link or an article?

Denis

Industrial Waste Reduction, Iron Castings for Industrial Markets - Waupaca Foundry

You Like Ward fittings ?

American made and all.

WARD FITTINGS - WARDMFG

I suspect they use the above linked foundry (within 10 miles,
and all under the same corporate blanket).

High volume castings can be made very well, and the "scrap" can just
be returned to the ladle.

Here you go--> Videos | AB&I Foundry Look at the 15min factory tour video. Bonus is that you can see the Haas VF tool changer angle brackets they make.

My guess would be shell casting, where fine grained foundry sand and a binder are baked over (usually) aluminum pattern plates to create female mold halves.

I think it'd fascinating that these little lumps are still cast, then threaded in a separate op. I would think a CNC lathe, modified as needed for high volume, could spit these out PDQ and unattended.

Regards.

Mike

Finegrain said:

I think it'd fascinating that these little lumps are still cast, then threaded in a separate op. I would think a CNC lathe, modified as needed for high volume, could spit these out PDQ and unattended.

Regards.

Mike

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From what I have seen, a special rotary machine called a Goss & Deleeuw is used for these.

Machinery Values, Inc. - 3'' Chuck Goss & De Leeuw 1-2-3 AUTOMATIC CHUCKER (Ref No: 11599)

Sort of like a Kingsbury, only quicker to change over.

Finegrain said:

I think it'd fascinating that these little lumps are still cast, then threaded in a separate op. I would think a CNC lathe, modified as needed for high volume, could spit these out PDQ and unattended.

Regards.

Mike

Click to expand...

Indeed, they surely could be made from “billet” steel, but cast iron itself has some desirable properties with respect to corrosion resistance and casting all the features except for the threads does save a lot of machine time. As shown in the video linked by Tkassoc, much of the casting work can be done robotically.

Incidentally, I pointed out the detail of this particular casting to the plumber at our locally owned hardware store (not a box store staged by minimum wage newbies) and he was surprised at the detail as well. Compared to a lot of other fittings in the rack (which are perfectly fine for the purpose) there was noticeably greater crispness and sharper detail in some of the castings like the one photographed.

Denis

dgfoster said:

I have more than a casual interest in the process of casting iron. I recently purchased a 3/4” cast iron pipe plug. So what, right? Well, what struck me was how crisply cast this part was—-see the embedded photo. Obviously they are pumped out in huge quantities and in great variety on a daily basis. So, any attention to detail on individual pieces is impractical. This part seemed to be sand cast based on its surface texture, but I am not sure about that. Also obviously, it was made in China.

I looked on the Web for videos or descriptions of how these parts were made, but found practically nothing. Does anyone have information about this? Maybe a video link or an article?View attachment 214724

Denis

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often not done with just green sand but with sand and a binding agent. in the old days you would take sand and molasses or linseed oil mix and bake it hard like a cookie. once exposed to molten metal the binder is burnt or weakened that the mold breaks apart easier.
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now a days they use chemicals some harden with C02 gas others harden like epoxy when mixed and others set when exposed to some heat but its not just baking more a chemical reaction. all molds need to hold up long enough for molten metal to solidify and not give off so much gas it causes problems.
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faucets for kitchen and bathroom the molds often are sand and binder. fairly durable til molten metal put in them. mold sand and binders is fairly advanced. some designed when molten metal put in to give off some gas for better surface finish.
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if you use plain sand often the sand is partially melted and stuck to casting giving a very rough surface. sand molding material mixes are quite advanced

DMF_TomB said:

.
.
often not done with just green sand but with sand and a binding agent. in the old days you would take sand and molasses or linseed oil mix and bake it hard like a cookie. once exposed to molten metal the binder is burnt or weakened that the mold breaks apart easier.
.
now a days they use chemicals some harden with C02 gas others harden like epoxy when mixed and others set when exposed to some heat but its not just baking more a chemical reaction. all molds need to hold up long enough for molten metal to solidify and not give off so much gas it causes problems.
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<Snip>
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if you use plain sand often the sand is partially melted and stuck to casting giving a very rough surface. sand molding material mixes are quite advanced

Click to expand...

Yes, I have spent some time in foundries and was impressed with just how hard and durable are the molds made modern binders. I mean hard like a rock and durable enough to commonly withstand shipping from a molding shop to a cast house to the be filled with iron, aluminum, or bronze. You would not want to try that with greensand. Those binders setup in a half hour or so. Sodium silicate (water glass) sets up like a rock (unless intentionally weakened) in seconds when flushed with CO2.

Denis

For high volume you want a sand that is easy to recycle They use a mix of calibrated sand a clay powder Bentonite for example and coalpowder And some water The coal gives off a lott of gases at pouring creating a gas barier So you get a smoother casting
The make unsupported blocks of sand and set them up on a conveyer tight together Cores with a stronger binder (Co2 sand or PU sand or Furansand) are placed in the blocks of sand Metal is poured in automaticly
At the end of the conveyor the blocks fall down The castings are seperated and the sand is recycled Water added and reused At 5.30 you see the molds and the machine that makes the blocks of sand the casting and break up
The Official Lodge Cast Iron Foundry Tour - Extended Version - YouTube

Peter

I'm near an Anvil International plant. A large volume shop near me tried to quote machining ops on some flange parts for them to offload some of their production, they couldn't get within 2X of the price they needed to quote. Anvil has some old machines that don't have modern equivalents, like a twin spindle Vertical turning center with powered swingaway tailstocks, and the parts they do on them would be difficult to do on normal machines. They were trying to find alternatives before the machines are unusable, they are still looking.