Object weight for material conversion

[Kryten602]

Not sure if there is a quick way to determine this but if I have an irregular shaped, small solid object made in plastic that weighs 8g, what will it weigh if made in steel?

 

[Cabinetman]

I think it’s time for an Archimedes Eureka moment, Fill a jar with water and immerse the object – or 10 of them if it’s small, the water that overflows is the volume, then look online for the weight of steel for that volume, Ian

 

[Kryten602]

Cheers Ian, good call, well done and thank you.

 

[Richard_C]

I would do exactly as Cabinetman suggests, but I would also do a sanity check via arithmetic. There are all kinds of density tables on the internet. The ones below seem straightforward, especially if you know what the plastic is.

https://omnexus.specialchem.com/polymer-properties/properties/density
https://www.machinemfg.com/density-table-of-metals-iron-steel-brass-aluminum-alloys/
Most plastics are around 1.2 gm/ccm, most steels are around 8 gm/ccm: your 8 gram plastic item would be around 50 to 55 grams in steel (8x8/1.2).

The volume in water method will be more accurate, but I'm a pessimist, I like to do things 2 ways of I can to avoid silly errors on my part.

 

[TheTiddles]

If you know what plastic it’s made from, you can skip the water play, just use a calculator. 8g of water is a very small volume, your error will be large

 

[Alpha-Dave]

Is your object solid plastic or 3d printed with voids? If the latter, then 7x will be an underestimation.