Not sure I completely understand, but I'll tell you what we know;
This bush has 1/2" BSP internal thread, so will not accept a 15mm fitting.
The 15mm on a radiator valve refers to the pipework end, the other end will have 1/2" BSP thread, as this is the standard connection size on a radiator.
Hopefully this information helps you decide if the bush is suitable.
Thank you for using Q&A
Date published: 2016-11-20