These high quality ER20-A collet nuts have been precisely balanced for optimal performance and serve as a replacement for lost ones, they can be handy to have a few spare so you can pre-load different collet sizes and quickly swap both the collet and nut as needed.
 
Thread Options: 
Both options are standard ER20-A collet nuts, with the only difference being the thread size 
 
M24 x 1.0 (ER20-A) - Common on many standard ER20 spindles
M25 x 1.5 (ER20-A) - Typically used on larger or higher-powered spindles
 
While both hold the same standard ER20 collet, they are not interchangeable. Using the incorrect thread will prevent the nut from seating properly on the spindle.
 
PLEASE NOTE: Our newer stocks of ER20 collet nuts feature an off centre collet catch. This is designed to make removing collets a lot easier. While it may seem as though it will affect the run out, the collet should be perfectly seated in the nut housing. 
 
**Please choose your thread pitch very carefully to avoid puchasing the incorrect pitch.**