The value of tightening torque is relative not only to the nominal diameter and quality class of the bolt, but also to the security of the threaded fastener.

指出螺栓联接的扭紧力矩值不仅与螺栓的公称直径及性能等级有关，还与能否保证联接可靠工作有关。

Compared to the new wheel tread, the worn tread is easy to form two-point contact nearby the depression area of the nominal diameter position of wheel tread.

与新用车轮踏面相比，测试得到的磨耗后车轮踏面在其名义直径位置凹陷区域附近容易形成踏面两点接触。

Nominal diameter and flow valves, basically the same breath for full-bore type, Circulation than nominal diameter valve is given. it small called non-reducing type.

流道孔径与阀门公称通经，基本相同的为全通径式；流通孔径比阀门公称通经小的称为缩径式。

While ruffled tapered header general welding in two different nominal diameter of cylinder, make two nominal diameter of different cylinder is an organic whole repeatedly!

而折边锥形封头一般焊接于两公称直径不同的筒体中间，使两公称直径不同的筒体连为一体！

It's suitable for the small caliber valve nominal diameter: airproof test and strength test of DN15/100 flange type, through-type gate valve, cut-off valve and ball valve etc.

适用于小口径阀门通径：DN15/100法兰式、直通式闸阀，截止阀，球阀等阀门的密封测试和强度测试。

The reference standard, of convenient length, shall be prepared from a length of bar or tube of the same nominal outside diameter, material and heat-treatment as the material examined.

对比试块应从与待检材料有相同的公称外径、材质和热处理状态的棒或管上制取。