Is there a "Shields 101" in here somewhere?

[i_r_machinist]

Can someone explain the difference in some of these shield designs? All Hypertherm parts.
A 120930 shield is good for 40-80 amps has a .180" thru hole.
A 220404 finecut shield has about a 1/2" thru hole.
Why is this?
thanks
i_r_

[i_r_machinist]

AND, the 120929 has two groove cut across the face?
Why?
thanks
i_r_

[Largemouthlou]

One with the 2 grooves sounds like the drag tip for hand cutting
Other two are just what they say, one is for the fine cut nozzels, the other is for the 40 to 80 amp nozzels.

Don't have my manual here or I would explain more..

[jimcolt]

The 120 930 shield is used in conjunction with the shape of the nozzles to form a coaxial (patented) secondary air flow. Later systems (Powermax45, 65, 85 and 105 as well as all Duramax torches have a slightly improved design called conical flow, also patented) This flow gets pinched (impinged as our engineers say) by the fit between the nozzle and the shield.....which increases flow velocity and forces the flow on the already developed arc. The impingement increases arc energy density, controls cut edge angularity and provides for improved nozzle cooling. Better cut quality, longer consumable life.

The 220404 shield is strictly a shield that electrically isolates the FineCut nozzle from electrically arcing to the plate. The above technology (coaxial, conical) does not yet work with the FineCut consumables.

The shields with slots (castleations is the engineering term) are for drag cutting.....the shield keeps the nozzle from arcing to the plate, the castleations allow air to escape when piercing on the plate, and the height of the castleated shield holds the correct standoff for proper arc length when dragging.

Shields without castleations are for meachanized cutting with a height control or a standoff. When they are .060" off the plate...the arc length is the same as a castelated (drag) shield when dragigng.

There are no parts in a Hypertherm torch called a "tip". There is a swirl ring, an electrode, a nozzle and a shield.


Jim Colt

Can someone explain the difference in some of these shield designs? All Hypertherm parts.
A 120930 shield is good for 40-80 amps has a .180" thru hole.
A 220404 finecut shield has about a 1/2" thru hole.
Why is this?
thanks
i_r_