Meehanite Defects

[Phil SParticipant @phils66830]

What depth of defects in the surface of cast meehanite bar would be considered excessive ? Turned a 50mm bar down to 48mm and still have a defect of at least 0.5mm deep which is going to be close to the finished size.

Thanks

[noel shelleyParticipant @noelshelley55608]

The risk of defects in any cast item or material is always possible and not just on the surface. Bearing in mind the casting process, although efforts are made to remove slag or detritous both before and during the pour problems can still occur. Contact the supplier with a view to a replacement part or item. Taking only 1mm off is a small machining allowance.  Good Luck. Noel.

[Mark RandParticipant @markrand96270]

Pretty much none. What you have isn’t Meehanite, which is a trade marked production and quality control process.

The seller has used a false trade description for common continuously cast iron bar.

[Mark Rand]

On Mark Rand Said:

Meehanite.

As a seasonal observation: just as Christmas comes every year, every time that word is mentioned, you repeat that same statement.

There are innumerable things in this world where the registered name becomes common vocabulary – with what do you vacuum your carpet? What makes a lump of cast iron so special that it deserves this attention?

[Neil WyattModerator @neilwyatt]

This website gives a ‘surface machining allowance’ of <3mm for ductile cast iron (“S. M. A.” means ” Surface Machining Allowance”. That is the allowance of removing the surface irregular part.”)

https://www.us-metallteile.de/cast-iron-bars.html

As your defect is only 1.5mm below the nominal surface then it’s probably not unreasonable.

You should allow a  fair machining allowance anyway as ductile iron is often chilled on the surface, and you need to machine through this to get down to metal with the ductile properties you are paying for.

Neil

 

[DC31k]

On DC31k Said:

On Mark Rand Said:

Meehanite.

As a seasonal observation: just as Christmas comes every year, every time that word is mentioned, you repeat that same statement.

There are innumerable things in this world where the registered name becomes common vocabulary – with what do you vacuum your carpet? What makes a lump of cast iron so special that it deserves this attention?

We use a Roomba for the carpets 😀

The thing about ‘Meehanite’ is it is specifically different from other varieties of cast iron. In much the same way that D2 isn’t the same thing as EN24.

 

In the case of vacuum cleaners, the common (mis)naming is not intended to deceive a customer. In the case of the misnamed cast iron, the intent is very definitely intended to mislead the customer. This is an offence for which the supplier can be prosecuted…

[Neil Wyatt]

On Neil Wyatt Said:

This website gives a ‘surface machining allowance’ of <3mm for ductile cast iron are paying for.

Neil

 

Anything being sold as Meehanite is likely to just be grade 250 grey iron not ductile iron

[DC31k]

On DC31k Said:

On Mark Rand Said:

Meehanite.

[…] What makes a lump of cast iron so special that it deserves this attention?

I think the image in the opening post is sufficient to answer that question ^^^

Meehanite is not adequately defined as “a lump of cast iron”

Crows are black birds BUT not all black birds are Crows

MichaelG.

[Author]

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