毛孔
There is a pin hole between outside shell and output axis. 外套与输出轴的径向有一个插销孔。
Drilling method of pin hole: the pin hole shall be predrilled by supplier prior to hot dip galvanization. 销钉孔的钻法：销钉孔应为供应商在热镀锌预钻好。
Flux Corrosion is typified by pin hole leaks, generally in the bottom of a horizontal line. 典型例子是由于针孔泄漏导致的焊剂侵蚀，通常发生在水平管道的底部。
The paper analyses the necessity for piston in modern auto to adopt noncircular pin hole. 简述了采用活塞异形销孔的必要性及其结构特点。
The Si-Mn steel track plate and pin usually exist the early abrasion, one of the main reasons is the burr defect of pin hole. 硅锰钢履带板销孔存在脉纹铸造缺陷是造成履带板与履带销出现早期磨损现象的根本原因之一。
