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cast iron

Cast iron is a group of iron-carbon alloys with a carbon content greater than 2%. Its usefulness derives from its relatively low melting temperature. The alloy constituents affect its colour when fractured: white cast iron has carbide impurities which allow cracks to pass straight through, grey cast iron has graphite flakes which deflect a passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing.
Carbon (C) ranging from 1.8–4 wt%, and silicon (Si) 1–3 wt% are the main alloying elements of cast iron. Iron alloys with lower carbon content (~0.8%) are known as steel. While this technically makes the Fe–C–Si system ternary, the principle of cast iron solidification can be understood from the simpler binary iron–carbon phase diagram. Since the compositions of most cast irons are around the eutectic point (lowest liquid point) of the iron–carbon system, the melting temperatures usually range from 1,150 to 1,200 °C (2,100 to 2,190 °F), which is about 300 °C (540 °F) lower than the melting point of pure iron.
Cast iron tends to be brittle, except for malleable cast irons. With its relatively low melting point, good fluidity, castability, excellent machinability, resistance to deformation and wear resistance, cast irons have become an engineering material with a wide range of applications and are used in pipes, machines and automotive industry parts, such as cylinder heads (declining usage), cylinder blocks and gearbox cases (declining usage). It is resistant to destruction and weakening by oxidation.
The earliest cast-iron artifacts date to the 5th century BC, and were discovered by archaeologists in what is now Jiangsu in China. Cast iron was used in ancient China for warfare, agriculture, and architecture. During the 15th century, cast iron became utilized for artillery in Burgundy, France, and in England during the Reformation. The first cast-iron bridge was built during the 1770s by Abraham Darby III, and is known as The Iron Bridge. Cast iron is also used in the construction of buildings.

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  1. H

    Replace cast iron

    I would like to replace the cast iron branch with plastic but am not sure how far below the floor level I will find the point where the branch spigot enters the female fitting. The floor is in a garage and there is a room below that I cannot access therefore all work has to be done from above...
  2. I

    cast iron waste issue

    hi guys, I have a customer that has a downstairs loo that is too close to the wall for their comfort. They would like me to angle the loo to give them more leg room. Went round with a 4" flexi to find an ancient 3" bore cast iron pipe connected with a macfit. I have spent ages trying to find...
  3. S

    Cast iron question for the mature lot on here.

    Morning all, just a simple question for the forum elders:D What size cast iron is 95mm OD, would I be correct in thinking 3.5” old school? Thanks in advance
  4. S

    Cleaning 100 year old cast iron rads.

    Morning people, I’m in the middle of a listed building refurb. The customer is having overlay ufh throughout and using the original cast iron rads as the supplementary heat. I’m removing the top and bottom entry bushes to have them at the bottom, there’s lots of dried magnetite coming out. I’m...
  5. D

    Connecting to cast iron waste

    hi I had a leak in kitchen at point where 40mm plastic connected with 110mm cast iron (spigot?). The cement was crumbling away. I removed old stuff now looking to reconnect. Tried this - - but too large, internal opening is 90mm...
  6. G

    Replacing section of cast iron stack with plastic

    Hi. I am installing a downstairs toilet. My existing stack is cast iron. I don't really want to replace the whole stack so I'm hoping to to replace a small section at the bottom with a plastic t section. My question is if I chop the section out and replace with the plastic t, would it still...
  7. P

    Re using cast iron radiators

    I'm the maintenance guy for a client who owns a 1930's ex toffee factory which is up for redevelopment into housing. In the empty office building and ex social building there are cast iron rads that they are heating to stop freezing. I've advised them to drain them but they tell me that the...
  8. G

    Sealing a leaking strap boss onto 3 inch LCC (Cast Iron)

    Hi I've been asked to re seal a plastic strap boss which someone has bodged onto an cast iron waste stack. The strap boss is just above the old cast iron collar. The hole which it discharges through into the stack has been drilled slightly too small to work with the ridge on a 3 inch plastic...
  9. Bogart

    Cast iron rad tails affixing

    Is there any preferred method of connecting tails to a cast iron rad as opposed to a steel one? Manufacturer says use LSX, never tried this stuff. Thanks
  10. G

    Remove plaster and silicone from cast iron bath?

    I am reusing an old cast iron bath and it was chased into the wall at some-point. I have removed it to clean and to modernise the plumbing but am stuck with the best solution to cleaning plaster and silicone from the two sides where it was recessed. Any powerful cleaners that I can use on the...
  11. N

    Cast iron radiator fittings

    Hi all I am converting a 1910 community hall. It has 3 original cast iron radiators which are in good order but were installed via big steel pipe. The radiator fittings (connectors) are a big problem. At one end I have a steel pipe coming out with a 14tpi three quarter BSP tapered thread, that's...
  12. G

    Whats the best way to deal with rust around cast iron bath waste

    The customer dosen't want to change the cast iron bath but it has rust around the plug waste hole. It dosent look good and is difficult to clean. I've suggested touching up the bath with some repair enamel paint but now am not sure which product to use. Some of the product reviews are not good...
  13. L

    ptfe alternative??? ______________

    Hi all, Ive fit a cast iron radiator in my living room, at the flow and return there are two 11/4 to 1/2 reducing bushes, they're both dripping when the system is filled, I've wrapped the threads with a liberal amount of ptfe but to no avail, is they're anything else I could use? It's becoming...
  14. G

    I cant find a 1650 x 700 steel bath to replace old cast iron.

    Looked everywhere and I cant find a 1650 x 700 steel, not acrylic bath. 1650 x 750 is too big. I don't fancy chasing in a 1700 bath. Can anyone help? Cheers to anyone who can im going in circles searching online.
  15. J

    Cast iron soil stack

    The waste pipe that's been concreted into the building wall, and runs out into a cast iron soil stack has a crack in it. It is a part of the soil stack and will have to be cut out/or smashed out. If I was to cut the cast iron below this point, put a pvc branch in with a pvc to cast iron soil...
  16. Bibbs118

    Cast Iron style rads on 10mm

    Hi, A customer wants cast iron style rads throughout, 9 or 10 in total but currently has 10mm pipe . Is there any problems installing this type of rad on mircobore? I'm worried about the water content being much higher and it not circulating? Anyone else installed these on mircobore? Cheers
  17. Meady

    Joining cast iron soil pipe

    A mate of mine has just bought a house and wants to fit a toilet/basin downstairs. Only issue is the soil pipe is cast iron which I have never dealt with before. What’s the best way to connect onto it and what fittings do you think I would need? Cheers
  18. E

    More Cast iron radiator problems!

    Hi there amateur here looking for help again and as always any advice is very much appreciated :) We are working on a big renovation (our house and inlaws that we all chucked in for as a family) and previously had installed cast iron radiators in one half of the property. Apart from a few...
  19. H

    How should I connect to a 4 inch cast iron water main

    Hi I want to replace some old iron water main pipe and broken stop cock ideally with a larger bore pipe eg 28mm. In digging into the basement floor i found that the rougly 1 inch iron pipe comes off a 4 inch? Cast iron pipe. Not sure i dare try to unscrew the end cap. Should i just cut the iron...