A.¢23mm,¢24.8mm B.¢23mm,¢24.9mm C.¢15mm,¢24.8mm D.¢15mm,¢24.9mm
A.鋼度較高,導(dǎo)向性好 B.鋼度交底,導(dǎo)向性好
A.8~10 B.6~8 C.4~6 D.3~4