Placing one kettle on top of another kettle in not considered hatmana. However, on Shabbos, one should not heat cold water by placing on top of a hot kettle.

Squeezing a cloth or turban on Shabbos is forbidden. (It’s cleaning the material) The Rabbis do not let one place his turban in place where it will get wet so he won’t be tempted to squeeze out the water. There’s no such conern by an ordinary rag.

Usually, raw materials that will eventually be turned into felt or threads would be muktzeh on Shabbos. If someone used these materials before Shabbos for insulating foods, the Gemara is unsure whether the items remain muktzeh. Perhaps by using the items for insulation, they items have been “designated” and transformed into insulating materials and would not longer be muktzeh.

Stuffing a pillow for first time on Shabbos is forbidden. (מכה בפטיש) However, it is allowed to return the stuffing to the pillow if it fell out.

Ripping a material in a shirt for the neck-hole is forbidden on Shabbos for מכה בפטיש. A barrel with a sealed lid may be opened on Shabbos bc there it is two items sealed together, not making hole in one item.

Launderers would stitch garments together so they wouldn’t be lost in the laundry. The rule is that until one starts to rip away these stitches, the two garments are treated like one kli. This is relevant to the laws of tumah- if a dead rodent were to make contact with one garment, both would become contaminated. This is is because the launderer has an interest in keeping the clothes together, even after the act of laundry (in case they get dirty again). But other situations are not like this. For example, piece of wood temporarily stuck into an axe as a handle would bro become a “part” of the Kli when it’s not being used.

An oven with an attachment of a receptacle. R shimon says the receptacle is not treated as the same kli as the oven, but r Meir says that rabbincally, we are strict to consider them the same kli.

Two blades stuck together to make scissors- when they are being used, they are certainly considered one kli. If the scissors is not in use, then really they are not considered one, but the rabbis were stringent to treat them like one kli. If the scissors became tamei, the rabbis are also stringent and require that both blades individuals receive the ashes from the Parah Adumah to become pure.