Oxy Fuel Cutting
The width of the metal slot removed by the cutting process.
What is the kerf?
This type of flame—having a 1:1 mixture of oxygen and acetylene—is used for almost all oxyfuel steel welding.
What is a neutral flame?
Standard safety rules dictate that acetylene gauge pressure should never exceed this maximum psi.
What is 15 psig?
The color and thread direction used for oxygen hoses and regulator connections to distinguish them from fuel lines
What are green color and right-hand threads?
The minimum recommended shade number for protective filter lenses used in standard oxyfuel cutting and welding operations.
What is Shade 4 or 5?
The offset distance between the top entry line of the cut stream and its exit point at the bottom of the plate.
What is drag (or drag line)?
When adding filler rod to the weld puddle, the rod should be dipped into this part of the puddle, not melted directly by the inner cone.
What is the molten weld puddle (or leading edge of the puddle)?
Industrial oxygen cylinders are pressurized up to approximately this high pressure (in psi) at 70°F when full.
What is 2,200 to 2,400 psi?
This type of regulator reduces cylinder pressure down to working pressure in two separate stages to deliver a steady, non-fluctuating gas flow.
What is a two-stage regulator?
You should never allow oil, grease, or organic compounds to contact high-pressure oxygen valves because it can trigger this rapid explosion hazard.
What is spontaneous combustion (or explosive ignition)?
The minimum temperature to which steel must be preheated before the high-pressure oxygen valve is opened to start a cut.
What is kindling temperature (approx. 1,500°F / 815°C)?
A flame tuned with excess acetylene that shows a secondary white feather extending past the inner cone.
What is a carburizing (or reducing) flame?
Acetylene cylinders are filled with a porous mass containing this liquid solvent to safely dissolve high-pressure gas.
What is acetone?
This safety device, mounted at the torch or regulator, contains a porous metal filter designed to quench and stop a flame front travelling back through the line.
What is a flashback arrestor?
Before attaching a regulator to a gas cylinder, you should quickly open and close the cylinder valve to perform this maintenance step.
What is "cracking" the valve (to clear dust and debris)?
Technique used when piercing thick steel to prevent molten metal and slag from blowing back into the torch tip.
What is tilting the torch (or raising the tip slightly after preheat)?
This chemical agent (paste, powder, or liquid) is applied to clean non-ferrous metals like aluminum or stainless steel to dissolve oxides during welding.
What is flux?
This alternative fuel gas produces the highest total heat output (BTUs) per cubic foot, but has a lower inner-cone flame temperature than acetylene.
What is propane (or propylene)?
This specific type of torch mixing chamber uses high-pressure oxygen to draw low-pressure fuel gas (under 1 psi) into the mixing passage.
What is an injector-type torch (or low-pressure torch)?
Acetylene cylinders must always be stored and operated in this position to prevent liquid acetone from entering the regulator and hoses.
What is an upright (vertical) position?
For a metal to be cut using oxyfuel, the melting point of its formed oxide layer must be lower than the melting point of this.
What is the base metal itself?
Welding motion technique where the torch points back toward the completed weld bead, allowing slower cooling and deeper penetration on thick metal.
What is backhand welding?
The color and thread direction used exclusively for fuel gas hoses and regulators to prevent accidental cross-connection with oxygen equipment.
What are red color and left-hand threads (notched nuts)?
Soft metal alloys, such as copper or brass, are used for torch tip seats because they deform under torque to create this type of seal.
What is a metal-to-metal seal?
When opening an acetylene cylinder valve for operation, standard safety rules state it should be opened no more than this fraction of a turn.
What is 3/4 to 1 full turn (so it can be shut off quickly in an emergency)?