▁casting . ▁It ▁is ▁usually ▁more ▁critical ▁to ▁ensure ▁the ▁upper ▁chap lets ▁are ▁stronger ▁than ▁the ▁lower ▁ones ▁because ▁the ▁core ▁will ▁tend ▁to ▁float ▁up ward ▁in ▁the ▁mol ten ▁metal . ▁ ▁Che eks ▁ ▁When ▁casting ▁a ▁re entr ant ▁angle , ▁instead ▁of ▁using ▁a ▁core ▁a ▁che ek '' ▁can ▁be ▁used . ▁This ▁is ▁a ▁third ▁segment ▁in ▁the ▁flask , ▁in ▁addition ▁to ▁the ▁co pe ▁and ▁drag . ▁This ▁allows ▁the ▁entire ▁m old ▁to ▁be ▁made ▁from ▁green ▁sand ▁and ▁from ▁remov able ▁patterns . ▁The ▁dis adv antage ▁of ▁this ▁is ▁more ▁m old - making ▁operations ▁are ▁required , ▁but ▁it ▁is ▁usually ▁advantage ous ▁when ▁the ▁quantities ▁are ▁low . ▁However , ▁if ▁large ▁quantities ▁of ▁casting ▁are ▁required , ▁it ▁is ▁usually ▁more ▁cost ▁effective ▁to ▁simply ▁use ▁a ▁core . ▁ ▁See ▁also ▁Core ▁plug ▁ ▁Notes ▁ ▁References ▁. ▁ ▁Category : Cast ing ▁( man ufact uring ) ▁Category : Pl ast ics ▁industry <0x0A> </s> ▁was ▁a ▁town ▁located ▁in ▁Ha ib ara ▁District , ▁Sh iz u oka ▁Pref ect ure , ▁Japan . ▁It ▁is ▁notable ▁for ▁its ▁production ▁of ▁Sh iz u oka ▁green ▁tea ▁ ▁As ▁of ▁July ▁ 1 , ▁ 2 0 0 5 , ▁the ▁town ▁had ▁an ▁estimated ▁population ▁of ▁ 6 , 2 3 6 ▁and ▁a ▁density ▁of ▁ 5 1 . 7 6 ▁persons ▁per ▁km ². ▁The ▁total ▁area ▁was ▁ 1 2