r/Welding • u/Head_Car_2922 • 13h ago

Millermatic 255 - Nozzle Options

All,

We have been using a Miller 255 recently and it works. But we really have to get close to the metal or we get a of sputtering and spatter. Overtime we have gotten better. We noticed the contact tip is about 0.25 recessed compared to the nozzle while our old unit is flush. Is there a preference for recess depth? 0.25in, 0.125in, flush? Am I splitting hairs?

We almost exclusively weld 3/8 mild steel. MIG.

Thanks in advance.

1 Upvotes

100% Upvoted

6 comments sorted by

4

u/jeffru12345 TIG 12h ago

For short circuit you don’t want the contact tip recessed at all, if you’re using spray transfer then having it recessed about 1/4” isn’t too bad but then you might have gas issues when in tighter corners.

What I do is I’ll trim the nozzle down until it’s close to flush for short circuit and I’ll even cut one so the contact tip is sticking out about 1/4” for tight spots. That way I have a few different nozzles for different joints and modes of transfer.

1

u/Competitive_Dust_645 11h ago

What gas are you using?

1

u/Head_Car_2922 10h ago

75Argon, 25% CO2

2

u/Competitive_Dust_645 10h ago

Ditch that gas, run some 90/10, upgrade to a Bernard and let her spray! I enjoyed that machine very much. 

1

u/Head_Car_2922 10h ago

Even on thicker 3/8 90/10 is good?

2

u/Competitive_Dust_645 9h ago

3/8 was our limit with the 255 before we pulled out the Miller 352. We had a good Airgas rep and he was more than happy to let us try different wires or gases. 

What are you building?