Our glossary contains a number of terms to fire up your knowledge of torch applications and techniques. Look up terms alphabetically by clicking on the letters below or scroll down until you find the term you're searching for.

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A substance that is a mixture of two or more metals. Soldering and brazing rods are alloys with a melting point lower than the metals to be joined.


Heating, followed by cooling, to soften metal and reduce internal stress.

Automatic Ignition

A torch that is lit by turning the valve on then pressing a button that lights the flame. The flame is then extinguished by turning the valve off. Example: TS3500 Multi-Use Torch.


Also known as hard soldering or silver soldering. Joining metals by fusion of nonferrous (non-iron-containing) alloys that have melting points lower than those of the metals being joined. The filler metal is ordinarily in rod form. It bears some resemblance to welding with two differences: 1) brazing is done at a lower melting temperature than the metals to be joined, so the process is somewhat easier to complete than welding, 2) the two metals are fused by using a third - a brazing rod.

Brazing Rods

A rod consisting of a hard solder alloy that is used to join two metals together.

Capillary Action

The wicking action of solder or a brazing rod when it touches a heated metal. The alloy melts and is drawn into the joint through surface adhesion.

Emery Cloth

A cloth coated with abrasive grains used for polishing and cleaning metal.

Flame Cutting

Cutting steel by burning with an oxygen-fuel torch.


When a torch is turned upside down, liquid fuel gradually makes its way to the torch orifice. When this happens, a large amount of fuel may come out of the orifice, producing an uncontrolled yellow flame.


Special chemicals that clean and prevent freshly cleaned metal from oxidizing. It is virtually impossible to solder or braze any metal that is not clean or even slightly corroded. Corrosion is a form of advanced oxidation, and oxidation starts within minutes after any metal has been sanded, filed or cleaned. The type of flux to be used depends on the metal to be brazed or soldered.

Fracture Groove

A designed-in failure point in the torch, so that when the torch and cylinder are dropped, the fracture groove will fail prior to the cylinder center bushing failing. If the center bushing fails, then an 8 to 10-foot flame will erupt from the cylinder. Example: UL2317 Manual Torch, TS4000 High Heat Torch.

General Purpose Flame

This flame is tri-lobe and is slightly softer and less intense than other torch flames. This flame is appropriate for general applications, except where high heat intensity is required, such as brazing.

Hard Solders

Alloys that have silver, copper or nickel bases, used primarily for brazing.


Torches are used to harden materials through annealing, case hardening and tempering.

Instant On/Off

The torch is lit by pushing a button; the flame is extinguished by releasing the button. Example: TS4000 High Heat Torch, TS8000 Max Heat Torch.

Integral Orifice

An orifice that cannot be removed, lost or misplaced. It is built permanently into the torch. If a torch is assembled with a missing orifice, or does not form a gas tight connection with its mating part, then the torch could produce a large uncontrolled flame. This is prevented with the integral orifice.


The effect of uniting oxygen with metal. Rust is a common byproduct of oxidation. Oxidation over a period of time can lead to corrosion of the metal. The use of flux in metalworking prevents oxidation.

Pencil Point Flame

The flame, as it name implies, produces a fine point, which is needed when heat has to be concentrated into a small area. This flame is ideal for detailed and fine jobs.

Piezo Electric Igniter

A device that produces a spark used to light the torch. As the trigger is pulled, a hammer hits the Piezo-Electric Crystal, which generates between 14,000 and 16,000 volts.

Pressure Reducing Intake Stem

Built into the intake stem of all Bernzomatic brass torches is a pressure reducing device (variable orifice), that reduces the cylinder pressure to approximately 60 psi. This helps to eliminate flaring on brass torches.

Regulated Torch

This is a torch with a built-in gas regulator to reduce the cylinder pressure to approximately 25psi to 40psi. This allows the torch to work over a wide temperature range without changing flame size. In a non-regulated torch, as the cylinder pressure varies with temperature (37psi @ 0'F to 190psi @ 100'F) so the flame will correspondingly change; constant adjustment of the torch is therefore necessary. Example: TS4000 High Heat Torch, TS8000 Max Heat Torch.

Silver Soldering

A form of brazing using rods that contain a silver alloy.


Torches are used to soften products for removal (i.e. paint, adhesive, etc.).


A metal alloy with a low melting point. Solder is available in wire spool or bar form.


Joining metals by fusion of alloys that have relatively low melting points. As a general rule, soft soldering provides a less strong joint than brazing. Soldering is used most frequently in plumbing, where the leak-preventing qualities of solder are more important than a strong bond. It's also used for connecting wires together, when a good electrical connection is required.


A form of soldering in which the solder alone holds two pieces of metal together. It differs from soldering in that the metal work piece is reheated after the solder has been flowed into the joint.

Swirl Flame

Also known as Turbo, Tornado or Vortex Flame. A pencil or general purpose flame has a primary and secondary flame, just like a candle. The swirl flame holder acts like a tornado, creating a vortex to mix the primary and secondary flames together. This does two things; it creates a smaller and tighter flame, therefore producing a higher heat concentration on the work piece, and secondly, the gas that is wasted in the secondary flame is now mixed into the primary flame so it more efficiently uses fuel. This flame is good for most applications except when a very low heat intensity is required.


In soldering, dipping the torch's soldering tip attachment in a flux paste and applying solder to the tip until it is completely covered. This leaves the tip bright, shiny and properly coated, which enhances heat transfer when soldering electrical connections and jewelry.


Also known as gas fusion welding. A metal-joining process that uses the heat generated by a combination of oxygen and a gas to melt two similar metals so they flow together and are integrally joined when cooled. This melting actually forms a puddle of molten metal. When the puddle cools, the repaired area should be as strong as the parent metal. Although this definition does not indicate the need of an additional metal source, a filer or welding rod is often used to fill gaps and smooth the finished joint.