Mig Nozzels & Tips

admin

Oh Happy Day! My brand new MM 251 is now sitting next to my SW 250.  Got it all set up last night. No sparks yet but this weekend for sure. Looking forward to learning the Mig processes.I got the convenience kit for the M25 gun that came with it. It came with an additional nozzle, tips, o-rings etc. The extra nozzle is not the same as the one that came with the gun. The one on the gun tapers down to a .500" opening and the one in the kit is .625".  What are the determining factors for choosing different nozzles? Are certain ones more suitable for different processes such as short circuit vs. spray? I have read some information about tip position relative to the nozzle but have not found anyhing about nozzle size and taper. Thanks for any help you can offer.Allen
Reply:First things first.Before you plug that bad boy in, make certain the voltage jumpers are set correctly for your power supply.  My MM251 came set up for 460V, and I had to go back to the store and swipe a second jumper off another machine so I could start welding.  I understand there are actually several versions of the MM251 out there, so I'm just suggesting you check it out.As far as the nozzles go, I prefer the 1/2" nozzle for most SC applications.  The diameter of the nozzle controls the shape ofd the "cloud" of sheilding gas, but limits access to the joint.  Joint design will dictate which nozzle you wil use.  As far as the relationship of the tip to the nozzle, the tip should be flush for SC, but about 1/8" recessed inside the nozzle for spray.  You can either slide the factory nozzle down a bit, or buy an extended nozzle.  I prefer using a larger nozzle for most spray applications.Be aware that you can get tapered nozzles down to about 3/8" dia.  These are awesome for tight areas.  Good luck, and enjoy your machine.
Reply:Thanks Aaron, that helps.Mine is set for 230. There are two basic units for the MM251. One is for 208/230v and the other is for 230/460/575v. I got the 208/230v model and yes I have checked the jumbers.Doing some additional research today I found out that there are three different basic nozzles. One having the tip flush, one recessed about 1/8" and one for the tip sticking out about 1/8" aavilable in .500" and .625".   I didn't see anything with a 3/8" opening however.Can't wiat to get started.Allen
Reply:Originally posted by ralenr Thanks Aaron, that helps.Mine is set for 230. There are two basic units for the MM251. One is for 208/230v and the other is for 230/460/575v. I got the 208/230v model and yes I have checked the jumbers.Doing some additional research today I found out that there are three different basic nozzles. One having the tip flush, one recessed about 1/8" and one for the tip sticking out about 1/8" aavilable in .500" and .625".   I didn't see anything with a 3/8" opening however.Can't wiat to get started.Allen