, ▁also ▁called ▁" manual " ▁or ▁" po cket " ▁sh ar pen ers ▁in ▁the ▁United ▁States , ▁have ▁no ▁separate ▁moving ▁parts ▁and ▁are ▁typically ▁the ▁smallest ▁and ▁che apest ▁commonly ▁used ▁p enc il ▁sharp ener ▁on ▁the ▁market . ▁The ▁simplest ▁common ▁variety ▁is ▁a ▁small ▁rect angular ▁pr ism ▁or ▁block , ▁only ▁about ▁ 1 ▁× ▁ 5 / 8 ▁× ▁ 7 / 1 6   inch ▁( 2 . 5 ▁× ▁ 1 . 7 ▁× ▁ 1 . 1   cm ) ▁in ▁size . ▁The ▁block - sh aped ▁sharp ener ▁consists ▁of ▁a ▁combined ▁point - sh aping ▁cone ▁that ▁is ▁aligned ▁to ▁the ▁cyl ind rical ▁p enc il ▁alignment ▁guide ▁hole , ▁into ▁which ▁the ▁p enc il ▁is ▁inserted . ▁ ▁A ▁sharp ▁bla de ▁is ▁mounted ▁so ▁that ▁its ▁sharp ▁edge ▁just ▁enters ▁the ▁sh aping ▁cone ▁tang entially . ▁ ▁The ▁p enc il ▁is ▁inserted ▁into ▁the ▁sharp ener ▁and ▁rot ated ▁while ▁the ▁sharp ener ▁is ▁held ▁motion less . ▁ ▁The ▁body ▁of ▁the ▁sharp ener ▁is ▁often ▁cont oured , ▁rid ged ▁or ▁gro oved ▁to ▁make ▁the ▁small ▁block ▁easier ▁to ▁firm ly ▁g rip , ▁and ▁is ▁typically ▁made ▁of ▁al umin um ▁al loy , ▁mag nes ium ▁al loy ▁or ▁hard ▁pl astic . ▁ ▁The ▁bla de ▁inside ▁the ▁sharp ener ▁sh aves ▁the ▁wood ▁and ▁graph ite ▁tip ▁of ▁the ▁p enc il , ▁while ▁the