1 ? ?????? ??? ????? ????????? ???? ???? ???? ????? ????????? ? ???? ????. ???? ? ???? ???? ????? ?????? ? ???? ????? ????.

2. ????? ????????? ????:

?????? ???? 5A50 ????????? ?? ??: 265MPa ? ?????? ???? 3A21: <167MPa ?

?????? ???? duralumin 2A11: 370MPa ? ?????? ???? 2A12: 390 ~ 420MPa ? ?????? ???? 2A13: 315 ~ 345MPa ?

3. ?????? ???? ????????? ???? ?????: 80 ~ 100MPa?

4. ?????? ?????? ?? ??? ???? ??? ?? ???? ?????? ???? ??? ? ????? ???????? ? ???? ????? ?? ????? ???? ????? ?? ??? ??? ???.