High Frequency
Weld stronger with steps and larger juncture plane
For different drilling machine spindle to match
different screw.
*M22 Beijing silk buckle
* M32 ( 1-1 / 4-3 ) Tongling silk buckle
* M33 west flying silk buckle
* M38 Xianxian silk buckle
* M36 Guangzhou silk buckle
* M32 Taizhou buckle
* 1-1 / 4-7 UNC
* 1 / 2 BSP