The tip was hooked towards the edge, the same way the tips are hammered for knives used for slaughter.
( ( The tip ) ( ( was ( hooked ( towards ( ( ( the edge ) , ) ( ( the ( same way ) ) ( ( the tips ) ( are ( hammered ( for ( knives ( used ( for slaughter ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (NN tip)) (VP (VBD was) (VP (VBN hooked) (PP (IN towards) (NP (NP (DT the) (NN edge)) (, ,) (NP (NP (DT the) (JJ same) (NN way)) (SBAR (S (NP (DT the) (NNS tips)) (VP (VBP are) (VP (VBN hammered) (PP (IN for) (NP (NP (NNS knives)) (VP (VBN used) (PP (IN for) (NP (NN slaughter))))))))))))))) (. .)))
They were fragile and could not leave a scratch. 
( They ( ( ( ( were fragile ) and ) ( ( could not ) ( leave ( a scratch ) ) ) ) . ) )
(ROOT (S (NP (PRP They)) (VP (VP (VBD were) (ADJP (JJ fragile))) (CC and) (VP (MD could) (RB not) (VP (VB leave) (NP (DT a) (NN scratch))))) (. .)))