A puller head mold for receiving molten metal or alloy during the casting of an ingot, the puller head mold having a tapered screw thread structure. The tapered threaded puller head is used to pull and withdraw a cast ingot from a casting furnace, and can be particularly useful for the handling of ingots having a relatively narrow diameter. The tapered threaded puller head profile provides for full release of the tapered threaded puller head from a cast ingot in a fraction of a turn. The size and profile of the cast ingot formed with the tapered threaded puller head is resilient to thermal gradients while cooling.

A bottom block for use in direct chill (DC) casting that includes a flared base providing additional surface area for contact with coolant used in the DC casting process. The bottom block includes a first end that substantially fits within a DC mold while a second end has a larger cross-sectional area than the first end. A transition between the first end and the second end provides a surface for coolant to contact despite film boiling and air gaps between the ingot and the coolant.