12.1 The Background of OFC

Karl Fulton

The Development of OFC

A historical photograph of five men of different racial backgrounds in a workshop, welding. The top right of the picture is labeled oxy-acetylene welding.
Figure 12.1. Oxyfuel Welding Circa 1917 – 1920 / Photo Credit: The Library of Congress, PD

The Basics of the Process

Oxy-Fuel Cutting is one of the most vital skills for a welder fabricator to master. This operation allows you to cut carbon and low alloy steels accurately at a wide range of thicknesses depending on your torch setup. This process is not used to cut metals that do not rapidly oxidize, such as Stainless steel and high alloy steels.

Railroad rail cut on the end with oxy-fuel. The cut shows some melted metal toward the base of the cut, and the edge looks a bit like melted wax on a candle, showing how oxy-fuel cutting heats the metal in order to cut through it.
Figure 12.2. Rail from the Railroad Cut / Photo Credit: Jens Galsgaard, CC BY-SA 3.0

It all starts with a torch hooked up to a fuel bottle and an oxygen bottle. Once the flame has been adjusted to a neutral flame the metal is heated to its kindling temperature of approximately 1400 degrees F then adding an additional jet of oxygen in the center of the preheat flames. This causes the metal to oxidize rapidly or burn. The burning/molten metal will run off as slag as the torch moves. This can shape the edge, pierce holes, or cut a slit in the metal, in all cases the edges that are left behind are known as the Kerf. This can produce a clean finish with practice and can easily be mechanized to bevel plate, pipe, or even connected to a CNC machine.

The basic equipment needed for OFC includes

  • Fuel and oxygen bottle
  • Regulators
  • Fuel hoses (red) Oxygen hose (Green)
  • Torch body
  • torch tips
  • Striker/fiction ignitor (never use a lighter or matches)
  • PPE
  • Shade 5 or higher cutting goggles
  • Leather gloves
  • Appropriate welding shop attire

Uses of OFC in Industry Today

You will see OFC in just about every shop you go into that deals with ferrous metals. This will include:

  • Job/fabrication shops
  • The railroad
  • Pipeline
  • Structural steel industry
  • Maritime construction and repair
  • The hobbyist garage.

Attributions

  1. Figure 12.1: Oxy-acetylene Welding (LOC) by The Library of Congress in the Public Domain; United States government work
  2. Figure 12.2: Torch cut rail by Jens Galsgaard is released under CC BY-SA 3.0
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License

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Introduction to Welding Copyright © by Karl Fulton is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.