Newbie welder question.

Thanks for the replies guys. I was worried about bad contact as well that's why I asked. I was just thinking it would be easier and cheaper to just buy one size tip lol not a big deal deal tho I have a few 30s that came with the machine and just bought a pack of 25 of the o35s that should last me a lifetime no more than I weld!! To answer someone's question I dont have a large machine it's a harbor freight 125 it's made by Chicago I think. It says in the manual I can use either. 030 or 035. It's a flux core only welder so I doubt I could use .023. So far using the cheap hf .030 brand wire iv had pretty good success with the little welder. I'm still learning how to weld I'm no pro I'm sure ones I learn more and practice and hone my skills it will perform even better. Ppl talk so much bad things about them and I dont why. Maybe its because i never used anything high dollar so i dont know what I'm missing lol but for 89 bucks its sticks two pieces of metal together pretty darn strong!!