Miriam,
The 1/2 x 10-28 means 1/2 inch length (of threads), size 10 diameter (at the threads) and 28 threads per inch.
The 10-28 screw fit both my 15-91 and the 201-2.
Cathy
Originally Posted by
miriam
kidding about JB weld. I have no clue what the 10-18 screws mean. They are just screws. It went on a Singer 15 not a 201. I'm not sure I want to take it off - I put them on pretty tight.