ASTM A320 Gawo l7 ndi lingaliro lazinthu za ma bolts, ma studi, mtedza, ndipo zofunkha zina zimapangidwira kutentha kwambiri. ASTM A320 L7 Magiredi agawidwa m'makalasi 4 a magwiritsidwe, a, b, c, ndi d, aliyense wokhala ndi vuto lalikulu komanso lopanikizika. Makalasi 660 amagwiritsidwa ntchito ku boll bolodirs, mitsempha yamavuto, chitoliro chimakongoletsa ndi mavuwo otentha kwambiri.