Harris welding tip sizes

[jerryo]

I need to OAW some 1/8" sheet metal pieces and have access to a Harris torch setup with an assortment of welding tips. I've OAW'd with Victor equipment a lot in the past, but I am not familiar with Harris tip sizes/metal thickness requirements. Harris seems to use a different numbering system than Victor. What size Harris welding tip should I use for 1/8" metal?

[Zrexxer]

http://www.hobartwelders.com/weldtalk/attachment.php?attachmentid=25409&stc=1&d=1201795610

[gatkeper1]

Look here for Harris tip charts
http://www.harrisproductsgroup.com/equipment/cuttingtips.asp?ID=23A90
http://www.harrisproductsgroup.com/equipment/cuttingtips.asp?ID=5090
Take a look at this tip chart to help determine comparative tip sizes
http://www.bikesmithdesign.com/Welding/Tips.html

[cpurvis]

The chart for Harris tips makes sense...smaller tip, lower pressure. The tip number corresponds with the pressure. How about that?

Why does Smith recommend 10psi for everything?

[Aerometalworker]

The chart for Harris tips makes sense...smaller tip, lower pressure. The tip number corresponds with the pressure. How about that?

Why does Smith recommend 10psi for everything?

Dont get caught up on pressure, thats more derived from the safety aspect when using a cutting torch. Honestly you only need enough pressure at the regulator to move enough volume of gas through the welding tip for the size flame you want. Higher pressures only make the valves on the torch more sensitive. My old Smith book ( circa 1933 ) describes the procedure to set regulator pressure:

1-both regulator controls turned all the way out, tank valves open
2-Open BOTH valves on the torch 1-2 turns
3-Slowly screw in the Fuel gas regulator until you feel a small stream of fuel coming from the tip when held against your cheek (no kidding)
4-Light the torch ( after moving away from cheek)
5-turn in more or less fuel to get a bushy yellow flame ( no soot ) that is not detached from the tip.
6-slowly turn in the oxygen regulator to get a neutral flame.
7-Alternately turn up fuel and oxygen to get a strong flame from the tip
8-Now you can dial the flame down with the torch knobs


Now the nice part is, after the regs are set this way, you can re-light the torch by opening BOTH valves about 1/4 - 1/2 turn and lighting. No soot, and a clean light every time.

NOTE: THE ABOVE PROCESS IS FOR WELDING TIPS ONLY, NOT CUTTING!!!

-Aaron