Looking for cast iron bars

[Steamchick]

Arnie: "How about some old window weights?"

No, No, No... Please don't!

These were made from unknown scrap!
Foundries use all the good (lab tested) material to make good castings that sell commercially. BUT any dead-weights are usually made from the scrap they cannot supply to someone who wants anything with any strength, machining ability, other mechanical properties, etc.
I have wasted a few good hours playing with lumps from sash weights my Father left me...
I managed to make 1 lump into a simple cylinder flywheel for a marine engine. 2 in diameter (very roughly) and 2 in long, with a hole through the middle. It cost me more for the messed-up drills. 2 HSS and 1 masonry drill! It was annealed at least 3 times before I even started.
Another lump made a back-tool-post for mounting a parting tool on the lathe. Rough as anything! A hard B#'@g%$r to cut!
The last bit has made a hammer-head - so hard it knocks chips off a regular hammer! Needs more fine grinding to smooth-out the lathe tool marks.

MUCH better is to get a cam-shaft or crank-shaft from a scrap yard, cut-off the cylinders you need, anneal if too hard, then use those as "cast iron". Old Brake cylinders are good to use, or any other car parts that have had some machining - like flywheels and brake discs, as they have been bought as good quality material in the first place. But why not simply use mild steel for most things? (I do) - In most instances, the model won't know.
K2

 

[GreenTwin]

Sash weights in the US seem to all be made from trash metal, which is the metal that is not of any use for anything, and would normally be discarded, but instead was cast into sash weights.
Absolute garbage from what I have seen, but useful as a sash weight.

.

 

[Richard Hed]

Since no one else has mentioned it yet...

If you don't need a long length, you can try using black cast iron threaded pipe fittings. If you are lucky, you may have a long-established plumbing-supply business or hardware store near you where you can find old stock from decades ago.

Someone posted about cutting up small anvils from Harbor Freight and other similar stores.

Others have suggested barbell weights and dumbbells.

I know this doesn't provide nice 1-in. diameter bars, but if nothing else is available in your area at your price this might help.

--ShopShoe

FYes, yes, very good idea. At one of my local scrap yards I managed to find some kind of CI "somethings" which are about 12" long, 5-6 " wide and about an 1" thick. they have some holes for bearings or something and they are great for various pieces up to about 2" wide. I made a bunk of rounds out of half of one which I will use for Corliss valves if I mess anything up. I thimpfk I already meassed one up so will most likely use at least one. The CI is some odd kind stuff with larger than usual crystals.

 

[Richard Hed]

Arnie: "How about some old window weights?"

No, No, No... Please don't!

These were made from unknown scrap!
Foundries use all the good (lab tested) material to make good castings that sell commercially. BUT any dead-weights are usually made from the scrap they cannot supply to someone who wants anything with any strength, machining ability, other mechanical properties, etc.
I have wasted a few good hours playing with lumps from sash weights my Father left me...
I managed to make 1 lump into a simple cylinder flywheel for a marine engine. 2 in diameter (very roughly) and 2 in long, with a hole through the middle. It cost me more for the messed-up drills. 2 HSS and 1 masonry drill! It was annealed at least 3 times before I even started.
Another lump made a back-tool-post for mounting a parting tool on the lathe. Rough as anything! A hard B#'@g%$r to cut!
The last bit has made a hammer-head - so hard it knocks chips off a regular hammer! Needs more fine grinding to smooth-out the lathe tool marks.

MUCH better is to get a cam-shaft or crank-shaft from a scrap yard, cut-off the cylinders you need, anneal if too hard, then use those as "cast iron". Old Brake cylinders are good to use, or any other car parts that have had some machining - like flywheels and brake discs, as they have been bought as good quality material in the first place. But why not simple use mild steel for most things? (I do) - In most instances, the model won't know.
K2

In the case of rocking valves, if probably DOES matter, as CI will not rust like steel will. Also, it expandds differently than steel. But yhou're right, in most cases this will not matter

 

[Steamchick]

Thanks Richard. I could not have put it better... (I mean I didn't know any better!). Cylinder bores - Perhaps better in cast iron than steel? - because of lubrication? (oil retention?). Ground shafts - better is steel than Cast iron? (Strength? Surface finish possible? Fatigue resistance?). Camshafts - better in grey cast iron for high volume production (less costly machining?), but racing camshafts are machined from steel... Horses for courses?
K2

 

[GreenTwin]

Its the imbedded graphite.........nothing wears like iron.

In my opinion, nothing machines quite like gray iron either.

.

 

[Richard Hed]

There is that stuff called cast steel. I'm not sure exaactly how it is made but I know they make engine blocks from it and It is my understanding that it is rather tough. BTW, the differences in "strengths", for those of hyou who might not know:

toughness,
hardness,
compressive strength,
tensile strength,
impact strength,
machinability

are all different. Too often toughness is mixed up with other characteristics but really it belongs with machinability. Hardness is often a good characteristic and often not. With CI, Hardness equates with brittleness. Glass is stronger than most steels in tension but extremely low in impact strength. With concrete (yuou can make a lathe with concrete) compressive strength is relatively good but very poor with tensile unless embedded with strengtheners like GLASS or other fibres and/or rebar. My son goes on and on about basalt fibres being better than any other cheap fibres but nobody seems to be making it.

Of course, we are all concerned with machinability. Some aluminums, copper, titanium and special metals present problems we have all dealt with.

 

[GreenTwin]

Malleable iron and the more modern ductile iron are sort of hybrids, with some of the good characteristics of iron, but with a good bit of tensile strength and so not prone to cracking like gray iron.

If I ever find any nickle-mag I will be making ductile iron castings.

.

 

[abby]

Some engines are cast in aluminium or even magnesium , but most auto engine blocks are made from SG iron , that is spheroidal graphite iron which is a type of cast iron , it is not steel.
An engine block that is cast in steel would be very expensive and somewhat overkill.,Where would it be necessary ? Very large ship diesels are now mostly fabricated from steel as part of the hull , but not cast.
Casting more than a few grammes of steel requires energy levels beyond the reach of most ME workshops , unless wealthy enough to have induction melting and a couple of hundred amps of mains power.
Some ME's have played with thermite steel casting but not much documented.
Dan.

 

[LaFrance4]

I have bought cast iron from McMaster-Carr, Speedy Metals and Amazone.Com. Give them a try !!

 

[Steamchick]

Just found this simple explanation.

The 4 Types of Cast Iron​

Publish Date: July 30, 2019 | Category: Material, Metalworking

---

Consisting of iron with more than 2% carbon, cast iron is a versatile metal that’s used in a wide range of consumer and commercial applications. It’s been around since the 5th century B.C., during which cast iron was used to make weapons as well as agriculture products. Since then, it’s become an increasingly common type of metal. While all cast iron has a carbon content of over 2%, though, there are several different types of cast iron, each of which is unique.

#1) Gray Cast Iron​

The most common type, gray cast iron features a graphite microstructure consisting of many small fractures. It’s called “gray cast iron” because the presence of these small fractures creates the appearance of a gray color. When gray cast iron is produced, the fractures open up to reveal the gray-colored graphite underneath the surface. Gray cast iron isn’t as strong as steel, nor is it able to absorb the same shock as steel. With that said, gray cast iron offers similar compressive strength as steel. As a result, it’s become a popular choice of metal for applications involving compressive strength.

#2) White Cast Iron​

While not as common as gray cast iron, white cast iron is another type worth mentioning. It receives its namesake from its off-white color, which is the result of iron compounds known as cementite. Like gray cast iron, white cast iron features many small fractures. The difference is that white cast iron features cementite below its surface, whereas gray cast iron features graphite below its surface. The graphite creates the appearance of a gray color, while the cementite creates the appearance of a white color. White cast iron is hard and offers excellent resistance against abrasions.

#3) Ductile Cast Iron​

Also known as nodular cast iron, ductile cast iron is a type of soft, ductile iron alloy with a high carbon content. It’s typically made with trace amounts of other compounds, including magnesium and cerium. When added, these trace compounds inhibit the speed at which graphite grows, thereby keeping the metal soft and ductile. Ductile cast iron was invented in the early to mid-1940s.

#4) Malleable Cast Iron​

Finally, malleable cast iron that easily “workable.” It’s typically created using heat treatment processes on white cast iron. The white cast iron is heated treated for up to two days, after which it’s cooled. When finished, malleable cast iron can be bent and manipulated to achieve unique shapes and sizes.

Steel - much lower Carbon content) has much better tensile and other properties. - And there are thousands of different steels for different applications.
K2

 

[Steamchick]

Medieval Blacksmiths used to hammer the carbon out of cast iron (when red hot) to produce Wrought iron and steel. The carbon was the reason they were BLACK Smiths!
K2

 

[HMEL]

You can get 1" meehanite bar in UK from several suppliers , postage should not be too much.
Dan.

Would you really want to use meehanite? It is especially high in carbon and mostly used in very abrasive environments and very brittle when you work with it. Just curious for all I know maybe its better than I think it is.

 

[ccdedon]

For some cast iron parts i have used old camshafts from auto engines.
W5RA CC Dedon

 

[Steamchick]

So have I. pistons, etc. And used a Cast iron pipe fitting to make a cylinder. I guess grey cast iron is Meehanite? Spheroidal graphite iron is "ductile iron" in the earlier explanation?
K2

 

[L98fiero]

So have I. pistons, etc. And used a Cast iron pipe fitting to make a cylinder. I guess grey cast iron is Meehanite? Spheroidal graphite iron is "ductile iron" in the earlier explanation?
K2

Meehanite is a trade name and according to the corporation, "Meehanite® metal is a family of different types of superior engineered cast irons, including nodular iron, flake graphite and white cast irons. The key to the undisputed success of Meehanite® metals is the rigid application of its patented manufacturing process." (emphasis is theirs) A cast iron pipe fitting might be good iron, but it's definitely not Meehanite®.

 

[abby]

Would you really want to use meehanite?
These piston rings are 1/2" od , machined from 1" dia meehanite bar (the grey iron variety).
It machines beautifully and is of guaranteed quality, thats why I would use it.

 

[Bentwings]

Wherever you find the cast iron, the best rings seem to always have been of the 40K cast iron. 10 V-8s have been made using this material for the rings. They fit well and don't smoke.

Actually I think you could call perfect circle piston rings and either have them made or purchase off the shelf even if you have to modify piston design a little

 

[Steamchick]

Piston rings, ball races, high tensile bolts, electronics, etc. etc. are things I buy, not make. Factory precision, from material selection and control to finished sizes, including heat treatment, is at least 1 order of magnitude better than almost any Home Workshop, where the set-up alone can be 0.001" off-true in many cases...
K2

 

[abby]

But some stuff you just gotta make it , even if it's just to see if you can.
Dan.