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.

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

Ok here is a crappy pic of the two kinds of throat plate screws. The one on the left was the same length and held fine - the one on the right did not hold. [ATTACH=CONFIG]470472[/ATTACH] It may be that not only do the screws vary but the belt guards may vary as well.

Miriam,

I'll check my bobbin winder hoods/ beltguards and see if there are differences.

Cathy

Cathy, I worked on another Singer 15 - I pulled it's half dead potted motor this morning - there is no way the throat plate screw goes in that one - I don't know if it has something crudding the hole or if it is a different thread pattern. It goes about a half turn- go figure.

Murphy's law strikes again! VBG

Cathy

Do you have thread/ tap gauges to check the thread size in that hole?

If I do I don't know what they look like or how to use them... DH says we have some kind of tools to tap - inherited with the house.

gunsmithing suppliers are a good source for some "non-standard" screws with slots and undercut heafd. Are you sure those are #10? (OD about .192) for some reason I was thinking needle plate screws were smaller.

Well they fit the hole but some don't thread in very far.