四方钻杆和六方钻杆一、规格型号　　四方： 2-1/2” 2-7/8” 3” 3-1/2” 4-1/4” 5-1/4” 六方：3” 3-1/2” 4-1/4” 5-1/4二、产品描述　　使用AISI4145H合金钢制造。方钻杆的末端和驱动截面和接头都根据API规范来加工和检验。三、主要用途 方钻杆是整个钻柱的驱动部分Square Kelly and Hexagonal Kelly1. Specification Square Kelly: 2-1/2” 2-7/8” 3” 3-1/2” 4-1/4” 5-1/4” Hexagonal Kelly: 3” 3-1/2” 4-1/4” 5-1/4”2. Description AISI4145H alloysteel is used in producing the Kellies. Kelly’s’end, drive cross-section and joint are all processed and tested in terms of API.3. Main Function Kellies are the drive section of the whole drill stem. The manufacturing of the products refers to the standard of SY/T6509-2000 or API SPEC.7-1.