Remove the rod from the pierced hole before releasing the oxygen control lever. Oxygen must not
be shut off while cutting rod is inside a pierced hole or else the rod may seal itself shut or weld itself
to the target material.
e. When piercing is completed, first, remove the rod from the pierced hole. Secondly, release the
oxygen control lever to extinguish the torch assembly. The rod will continue to burn only as
long as oxygen is supplied.
HELPFUL HINTS:
Disrupting the oxygen flow may cause the rod to become lodged in the hole. If the cutting rod goes out
while piercing, the rod should be extracted immediately, if possible. The still hot rod can be re-ignited. If
the rod becomes lodged in the hole, release the torch oxygen control lever and remove the torch from
the cutting rod. The stuck rod can then be extracted by a gloved hand or pliers, or cut free with a new
rod inserted in the torch.
To avoid excessive blowback when starting a pierce, use the oxygen control lever to limit the oxygen
pressure to a moderate flow. When the penetration is approximately 1.5 to 2 inches deep, depress the
oxygen control lever fully to increase the oxygen pressure to maximum flow.
When piercing a hole deeper than 5 inches, it is best to use a 3/8 inch diameter rod.
3-4-2. Cutting.
Normal cutting is done by using a drag or pull technique. Push cutting (
see gouging
section below
) may be performed on thinner materials (same as diameter of cutting rod being
used). Following the ignition of a cutting rod, it is brought to the work surface that is to be cut. The
rod is dragged or pulled along the surface in the direction of the desired cut. The operator should
strive for a proper balance between the speed of the cut and rod consumption. When the operator
cannot see through the kerf (groove or notch made by a cutting tool), the speed of the cut is too
fast. (A sawing motion is used on materials thicker than 1-1/2 to 2 inches to ensure a complete melt
through.) When there are no other items to be cut, the oxygen control lever is released to
extinguish the rod. Comply with the following steps.
Always wear adequate protective clothing and eye and face protection. Exercise extreme caution.
Keep the burning tip of the rod in direct contact with target material.
a. Place the burning tip of the rod against the target material at a 45 to 90 degree angle. (A position
just off of perpendicular is preferred as the cross-sectional thickness is minimized.)
b. Increase oxygen flow by slowly depressing the oxygen control lever.
c. Keep the rod in the cut.
d. Pull the rod in the direction of the intended cut. Be sure that the molten material is blown forward
through the cut and does not splash backwards. The operator should look through the cut in order
to observe the spray. If the spray deflects substantially, the operator is moving too quickly.
e. After completing the cut, release the oxygen control lever to extinguish the torch assembly. The rod
will continue to burn only as long as oxygen is supplied.
