The original oilers had a 10-32 thread. These 10-32 thread oilers are no longer available. The new oilers have a 6 x 1 mm thread. Additionally, all of the new saddle nuts have a 6 x 1 mm thread. If you are ordering a new oiler, be sure to measure the OD of the threads on your existing oiler. If the thread is 10-32, the OD will measure approximately .189″ (4.8 mm). Depending on your need for this oiler, you may also need to buy a new saddle nut as well.