I'd take it to a hardware store and check fit of what they have.
"It ain't what you're told, it's what you know." - Granny Weatherwax
Gather the villagers, pitchforks, torches; we march at dusk!
Some days, the supply of available curse words is insufficient to meet my demands.
.....Call me a craftsman, artisan, or artistic, and I will accept that. Call me an artist and you will likely get a quite rude comment in return. I am not a @#$%ing artist.
Yes they are commonly found metric threads. I made an aftermarket edge guide for mine. I purchased allen set screws, with a bronze tip insert from McMaster Carr.
I can't get to my base at the moment. It is in storage due to me moving. I was not able to locate thumb screws. I was more concerned with marring the "drill rod"
guide rods, also bought from McMaster Carr. They are sold in pacs of 5. I remember taking mine to a hardware store to find the pitch of the threads, as mentioned by Theo above.
Im sorry that I can't remember the size to give you.
Home Depot up here carries an assortment of metric bolts, at least out west here they do. Canadian Tire out here does too. You could try some bolts first while you look for the thumbscrews. The thread size for my DW611 turned out to be 6mm. I can't remember the pitch offhand.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.