GongYi #6 (13.2lbs-6kg) Clay Graphite Crucible for Metal Melting Casting Refining Gold Silver Copper Brass Aluminum

I bought the #4 and #6 crucibles. They arrived packaged very well in fitted foam inside cardboard boxes. They seem sturdy with thick walls. I am happy with the apparent quality and condition. I haven't fired them up yet but they came with instructions for seasoning them first. The widths and heights for both are about 1/8" smaller than the description, but that's close enough. As far as fitting tongs to them, the #6 has nearly straight vertical walls but narrows at the bottom, while the #4 noticeably tapers gradually a bit all the way to the bottom. My disappointment was that they hold smaller capacity than what was described. I filled them each to the brim with sand and then measured it. The #4 described as 490 ml holds only 400 ml of sand, while the #6 described as 710 ml holds only 575 ml. That means that the actual capacity of them is 20% less than the product descriptions show. On top of that, I had planned on filling them to 80% for safety but that means they will only safely hold maybe 60% of their described capacities. It makes me wonder if all sizes are that way. Maybe crucibles of any brand are measured this way and I'm just understanding it wrong, but now I know that I'll have to buy several sizes larger than I originally planned for my melt capacities. Other than that, I'm happy with them and plan to buy another larger one.

I used the #5S a few times now, which holds more than the #6 by volume, while costing less, and melted aluminum in it to about ¼ inch from the top of the crucible. It performed as expected.Each crucible came with the same data sheet in the box the crucible came in. Both data sheets are for the #6 crucible and not for the #5S crucible. It would be nice to have the correct data sheet for the #5S crucible.Some of the reviews look like they don’t know how to use these clay graphite crucibles, because you do have to keep in mind they are made of clay. You can’t fill them with metal to be melted that is forced into the crucible, even a little bit, because as the metal as it heated it will expand. This expansion can crack and even break your crucible. Also don’t let the metal harden inside the crucible after a melt. Pour any remainder out into a ingot mold. They can’t take shock as well. Banging it on the ground will in time break the crucible. Treating these crucibles like they are made of clay should make them last a long time.Now after a melt and pouring the remainder in an ingot mold there will be a little metal left on the sides of the crucible, and the fact that it is made of graphite makes this easy to remove after it cools.

I use this for aluminum exclusively and it’s holding up well after about 50 pours. Starting to show some signs of degradation but that is expected. Make sure to properly treat the crucible before first use.

Worked great heated nice no cracking and very durable

I am using these items for aluminum casting. They are working well.

Using for melting gold copper or silver

I upgraded to next day delivery and It was late by an additional day. The box was shipped in very sturdy container that was above quality compared to what I have gotten from other companies. Right out of the box there was several quality issues. There was a few DEEP gouges and cracks in the outer surface. You can tell they weren't caused from shipping related issues. They were def just lack of quality related. I haven't seasoned/cured it yet. I will update the review after usage.

Good price, decent quality. Melt tons of lead for fishing weights, works fine. Good price.