Yes, and they can be quite expensive. How many holes do you need punched? If it is only one or two, then a scribe, drill or scroll saw/coping saw to rough out -- a nibbler also works --, Dremel with carbide burr, and file will work fine.
I guess this is a good example of the laws of supply and demand. If db9 and db25 connectors were used a lot, say, on every one of the millions of personal computers sold in the last 20 years, the punches to make the mounting holes would be cheap, like $5 each. Right?
Yes, GREENLEE makes them; I have a 9 pin one right in my hand here. Alas, it's not mine, however....as they're quite expensive. If you plan on doing a LOT of this, it might be worth the investment...but otherwise, you''re best off borrowing one.
Thank you all for your help. I really appreciate it. Esp the pictures. )
I think I will have to go with the cheaper option because the circuits I have design are cheaper than the knock out punches. Maybe I will just replace the db9 connectors with something more rectangular and right angled.