1环压强度：环形试样边缘受压直至压搜时所能承受的zui大压缩力，以kN/m表示。 

2环压强度指数：平均环压强度除以定量为环压强度指数，以N·m/g表示。 

仪器 

1切样冲刀：可冲切尺寸精度达到本标准要求的冲刀。 

2,环压试验架试样座：内径49.30士0.05mm,槽深6.35士0.25mm.圆形槽底与试样座底面平行度偏斜不大于0.01MM.槽壁与槽底呈直角，夹角处不得有倒角与圆弧。为此，槽底和槽壁分两件加工再组装成一体。槽壁切线方向加工有宽度不大于1.25mm的试样插缝。 

   试样座配有不同直径的内盘，使试样座插入内盘所产生的试样夹缝适应不同厚度的试样（见表1）, 

                                 表 1            mm 

             试 样 厚 度                     内 盘 的 直 径 

              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