(c). 此鑄砂是屬於多少峯砂?:__________(請簡述理由)

ASTM
篩號數
50g 砂試樣殘留於篩上乘數乘積
6-(g)3-
12-(%)5-
200.30.6106
302.55.020100
402.55.030150
507.715.440616
7012.525.0501,250
10014.529.0702,030
1406.513.01001,300
2003.06.0140840
2700.51.0200200
pan(底盤)--300-
合計50.0100.06,492