what size end launch SMA would best fit a 1mm FR4 board?

what size end launch SMA would best fit a 1mm FR4 board that goes to microstrip? I looked at an SMA datasheet and looked at the end size and it was 0.037 + and - 0.003 as shown here on the dimensions of the SMA connector: https://imgur.com/a/Zi3ZI2r ... would this be a good fit, or what size would you pick for a 1mm sized FR4 board? It comes out that 1mm is 0.039'', but if I get my board manufactured, they might say the SMA does not fit, what size would you pick? I was thinking if the SMA is too large, this could effect the characteristic impedance when it is soldered onto the board, correct?

So, you expect a connector that could have a dimension as small as .034" to fit on a board that is .039" (+?)?. I think you're just asking for trouble if this is going to be a production board. Connector manufacturers usually specify the intended board thickness; find one that fits your board. Or contact the manufacturer and tell them what you're looking for. That's a lot safer than hoping it will fit and perform correctly.

I use 0.04" for 1mm PCBs.

Like this...

https://m.ebay.co.uk/itm/20pcs-SMA-f...r/161943542103

Yes i use those commonly for prototyping work. but i would NOT try them above say 3 GHz. The pin is too big, and the solder blob would have too much capacitance.

They are really only designed for use with FR4 thick boards.

It was a deliberate design choice to keep the cost low. I use it on an antenna and the efficiency only drops below 70% above 10GHz.