An Oxy Acetylene Flame will fall loosely into one of three types:

Neutral, Oxidising and Carburising

Neutral Oxy Acetylene Flame

A Neutral flame is achieved when there are equal amounts of Oxygen and Acetylene.

A Neutral Flame is so named because it has no chemical effect on the molten metal.

Key characteristics of a Neutral Flame are a defined Cone Flame at the base of a long feather flame.  If the correct size of nozzle is being used a Neutral flame should produce no more than a gentle hiss.

A Neutral Oxy Acetylene Flame is used for Welding, Brazing and Silver Soldering most metals and is therefore the most common type of flame to use.  A Neutral Flame is also used for Oxy Acetylene Cutting.

Oxidising Oxy Acetylene Flame

An Oxidising Flame is where there is more Oxygen than Acetylene used.

Key characteristics of an Oxidising Flame are a small, sharp, more pointed looking Cone Flame at the base of a shorter feather flame.  An Oxidising Flame will have a distinct roar.

Use of a slightly Oxidising flame is more specialised, typical uses are for welding copper and zinc based metals or manganese steels.  In these cases an oxidising flame creates base metal oxide that protects the base metal.

Carburising Oxy Acetylene Flame

A Carburising Flame is where there is more Acetylene than Oxygen used.

Key characteristics of a Carburising Flame is a secondary feather flame, caused by the excess Acetylene burning further down the flame length. If the correct size of nozzle is being used a  Carburising flame should produce no more than a gentle hiss.

Use of a Carburising Flame is more specialised, typical uses are for welding lead, surface hardening processes or welding high carbon steels.

I hope you found this blog article useful, if things work out well for you, please feel free to post some pictures of your achievements on our Facebook Page

Please let me know what you thought of this article by leaving a comment.  Don’t worry, your email address won’t be added to a database or shared and you won’t receive any unsolicited email.

Cheers

Graham