i bend the horn but it can not break by any way

a horn shape like this ) , i bend it to this shape <. it is not break,but keep the shape m, who know it why ?this horn thickness 0.5-0.7CM long 40 cm
boiled in the alkali and nitrite about 5 minute dryed one year :D , after i max bend want to break it , the horn keep the M shape more time .....