镗削有时也用于孔的加工。

镗孔机 

对较小的镗削加工过程可以在车床上进行，但对于较大工件的加工则需要使用特殊的镗床（工件围绕一个垂直轴旋转）或卧式镗床（围绕水平轴旋转）。通过转动变换刀具的安装角度也可以加工锥形孔。 

镗床（类似于铣床，如经典的范诺曼型）拥有多种尺寸和类型。工件直径通常是1 – 4米（ 3-12英尺） ，但也可达20米（六十英尺）。对电力的需求可高达200匹马力。其控制系统可以以计算机为基础，允许自动控制和提高一体性。 由于镗削加工可以降低产品上已有孔的公差，因此一些设计的注意事项必须得注意。首先，大的长径比是不希望的，因为这样会使刀具变形。其次，不能加工盲孔（孔的深度不超过工件的厚度）。中断的内部工作表面（即在刀具与加工表面间有不连续的接触）应该避免。装有刀头的镗杆是一个悬臂梁，必须有非常高的刚度。

锻造 

   锻造是一种利用局部压力使金属成型的方法。冷锻是在室温下或接近室温下进

行的锻造。热锻是在高温下进行，高温使金属更容易成形和降低断裂的可能性。温锻是在室温和热锻温度之间的温度下进行。锻造可对从不足1千克到170吨的工件进行加工。经锻造加工的零部件通常还需作进一步处理，以便得到最终的产品。

References

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2008;15:471–9.

[5] Chen Hsing-Sung, Tseng Pi-Tang, Hwang Shun-Fa. Failure analysis of bolts on an end flange of a steam pipe. Eng Fail Anal 2006;13:656–68.

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[7] American society for metals, metals handbook, 9th ed. Failure analyses and prevention, vol.11. Ohio: Metals Park; 1992.

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[9] Shigley JE, Mischke CR. Mech Eng Des. 5th ed. Singapore: Mc Graw-hill; 1989. 

翻译原文：

 Diesel engine connecting rod

Connecting rod 

In a reciprocating piston engine, the connecting rod or conrod connects the piston to the crank or crankshaft. The connecting rod was invented sometime between 1174 and 1200 when a Muslim inventor, engineer and craftsman named al-Jazari built five machines to pump water for the kings of the Turkish Artuqid dynasty — one of which incorporated the connecting rod. Transferring rotary motion to reciprocating motion was made possible by connecting the crankshaft to the connecting rod, which was described in the "Book of Knowledge of Ingenious Mechanical Devices". The double-acting reciprocating piston pump was the first machine to offer automatic motion, but its mechanisms and others such as the cam, would also help initiate the Industrial Revolution. 

Internal combustion engines  

In modern automotive internal combustion engines, the connecting rods are most usually made of steel for production engines, but can be made of aluminium (for lightness and the ability to absorb high impact at the expense of durability) or titanium (for a combination of strength and lightness at the expense of affordability) for high performance engines, or of cast iron for applications such as motor scooters. They are not rigidly fixed at either end, so that the angle between the connecting rod and the piston can change as eed. Failure of a connecting rod, usually called "throwing a rod" is one of the most common causes of catastrophic engine failure in cars, frequently putting the broken rod through the side of the crankcase and thereby rendering the engine irreparable; it can result from fatigue near a physical defect in the rod, lubrication failure in a bearing due to faulty maintenance, or from failure of the rod bolts from a defect, improper tightening, or re-use of already used (stressed) bolts where not recommended. Despite their frequent occurrence on televised competitive automobile events, such failures are quite rare on production cars during normal daily driving. This is because production autoparts have a much larger factor of safety, and often more systematic quality control.