1環壓強度：環形試樣邊緣受壓直至壓搜時所能承受的zui大壓縮力，以kN/m表示。 

2環壓強度指數：平均環壓強度除以定量為環壓強度指數，以N·m/g表示。 

儀器 

1切樣沖刀：可沖切尺寸精度達到本標準要求的沖刀。 

2,環壓試驗架試樣座：內徑49.30士0.05mm,槽深6.35士0.25mm.圓形槽底與試樣座底面平行度偏斜不大于0.01MM.槽壁與槽底呈直角，夾角處不得有倒角與圓弧。為此，槽底和槽壁分兩件加工再組裝成一體。槽壁切線方向加工有寬度不大于1.25mm的試樣插縫。 

   試樣座配有不同直徑的內盤，使試樣座插入內盤所產生的試樣夾縫適應不同厚度的試樣（見表1）, 

                                 表 1            mm 

             試 樣 厚 度                     內 盤 的 直 徑 

              0.150^-0.170                      48.80士0.05 

              0.171-0.200                       48.70士0.05 

              0.201-0.230                       48.60士0.05 

              0.231-0.280                       48.50士0.05 

              0.281-0.320                       48.30士0.05 

              0.321^-0.370                      48.20士0.05 

              0.371~0.420                      48.00士0.05 

              0.421-0.490                       47.80士0.05 

              0.491-0.570                       47.60士0.05 

              0.571-0.670                       47.30士0.05 

              0.671-0.770                       47.00士0.05 

              0.771-0.900                       46.60士0.05 

              0.901^-1.000                      46.20士0.05