Real stupid question

Today I was swapping out my old stock cat convertors with a new set from Magnaflow. I had all the old parts in a bin and some metal scrap guy came and took the stuff. Well the nuts that attach the cats to the stock manifold were taken too. Now I have no idea what size they were. Can someone tell me so I can go out and get some and this back on the road.

Thanks

thanks, I have the anti seize, I use that stuff on everything. Nothing worse than breaking your knuckles when trying get them suckers off later