AKS oxy-fuel configurations use the industry-leading torch assembly that matches our machines with reliability and accuracy.
All FIT + torches use the injector principle. This technology allow the mixture of preheat oxygen and fuel gas by a venturi principle injector ensuring the correct proportions and proper mixing. The benefits include reduced pressure and flow of fuel gas as well as reduced consumption in addition to increased life of the equipment and greatly improved safety by backfire reductions.
This technology creates a positive pressure through a proprietary valve that inserts oxygen pressure on the cutting oxygen channel during preheat and pierce.
The small oxygen flow cools the entire torch, including the mixed gases through the aluminum cooling body and prevents the reverse flow of hot gases into the cutting nozzle. Contamination is also avoided through this process.
Very high cutting speed may be achieved in these new torches due to a series of technologies and enhancements including:
The FIT+torches have a completely tool-free operation, meaning:
This FAQ is provided to help answer common questions about cutting with Oxy-fuel.
WHAT IS OXY-FUEL CUTTING?
Actually, oxy-fuel cutting is not really “cutting.” Technically, it is an intensified chemical reaction within the steel oxidation process that acts very rapidly and results in a “cut edge”.
Physically, here is what happens: The chemical reaction between carbon steel (iron) and pure oxygen creates iron oxide. This reaction can be thought of as specifically controlled “rusting.” The first step of the process is accomplished through the use of preheat flames to raise the surface edge of the steel to 1,800 °F, which causes the steel to glow bright red. Then, pure oxygen, introduced in a fine, high-pressure stream, is blown directly on that heated section of steel, causing high-speed rapid oxidation. As the steel oxidizes, the stream of oxygen also assists to blow away the slag that is created. It is during this controlled process, that the “cut edge ” is formed and the steel material is separated. On a CNC table, this preheating process and oxygen stream process is integrated together and powered along in a specific geometry and constant speed, to complete the “cutting” process, and produce a “cut part.”
WHAT MATERIALS CAN BE CUT WITH OXY-FUEL CUTTING?
In order to be cut by the oxy-fuel process, the metal has to be a ferrous material. Oxy-fuel process cannot cut aluminum, stainless steel, or other non-ferrous materials that do not “rust”, or oxidize, like carbon steel. If you tried to use the oxy-fuel process to cut other metals, the rapid oxidation process would not consistently occur, and the “cut edge” would not happen. Non-ferrous metals typically have oxides with a melting point higher than the base metal itself, so those non-ferrous metals oxidize quickly and pre-maturely, and a protective crust is formed, thus resulting in no material being removed, that is, no “cut edge” forming. The reason carbon steel works is because carbon steel produces an oxide with a lower melting point than itself, allowing for the rapid oxidation process to occur.
WHAT IS THE THICKEST CARBON STEEL I CAN CUT ON A CNC TABLE?
The oxy-fuel process is most popular on cutting carbon steel 2” – 6” thick. This is because up to 2” thick, typically laser and plasma cutting are more efficient, faster and more suitable for most fabrication shops. For carbon steel under 2”, the oxy-fuel process loses some of its efficiencies and benefits, and is much slower than plasma or laser. Under 2” carbon steel is almost always cut using plasma or laser, both of which will do a much better job, especially with new fiber lasers that can cut carbon steel up to 1.0” – 1.25”, and plasma that can cut material up to 2.25” thick. Depending on the part application and requirements, some might argue that 2 in. might not make sense for oxy-fuel cutting, but it may be worthwhile to review because oxy-fuel cutting process is very cost-effective for operating costs, and delivers a very nice “cut edge.” For all carbon steel above 2”, especially the very thick stuff, like 4” or 6”, the oxy-fuel process is very acceptable and common and produces a cut edge and cost that is inline with the fabricators needs. For thicknesses which have overlap, and could use oxy-fuel cutting or plasma cutting, plasma cutting is usually the chosen process, because the plasma cutting process is typically 5-10 times faster cutting than Oxy-fuel cutting.
WHAT CUT EDGE QUALITY CAN I ACHIEVE USING OXY-FUEL CUTTING?
Cut edge quality for oxy-fuel cutting process is usually very acceptable, especially when taking into consideration the thick metal parts it is being used to cut. Most importantly, you typically get nearly zero taper. The cut edge is perfectly perpendicular to the flat table surface on which the metal rests. The nearly zero taper and perpendicular cut edge usually surprises users, particularly those who are familiar with the taper left by plasma cutting, and to lesser extent, laser cutting. More specifically, the oxy-fuel cut edge also exhibits the following characteristics: square top corner and square cut face (relative to top surface); flat, clean and smooth cut face, with near vertical striation lines, from top to bottom; and little to zero slag, or dross, on bottom exit edge.
WHY HAVE AN OXY-FUEL CUTTING HEAD ON A CNC TABLE?
It all depends on the customer’s needs and part cutting applications. For many fabricators, they may hardly ever handle carbon steel over 2” thick, and rarely need oxy-fuel cutting capability. If they do, they can outsource it down the road to an outside supplier. For other fabricators, they may utilize thicker carbon steels, over 2” thick, only once and a while. In this case, they may decide to add a single oxy-fuel torch to their plasma CNC cutting table. In this case, they may only use the oxy-fuel torch once in a while, but when they need it, they have it. For other customers, like a steel service center, they may have a huge CNC cutting table with 6-12 oxy-fuel torches. They typically do large & thick carbon steel plates with repetitive parts. At the end of the day, for most customers, the typical solution is to purchase a X-Definition CNC plasma cutting table, and include a single oxy-fuel torch for those occasions where they need to cut thicker 2”+ steel parts.
WHAT GAS IS RECOMMENDED FOR OXY-FUEL CUTTING ON A CNC TABLE?
Most shops use natural gas, if it is available, because it is easy to set up and natural gas is very affordable. If you don’t have access to natural gas, then typically, the most popular selection for users is propane, as the next gas of choice. Fabrication shops can install a constant supply source inlet, or a bulk propane containment system, that is periodically refilled. Natural gas and propane are by far the two most popular choices due to availability and cost. Other gases like oxy-acetylene or methyl-acetylene, are more expensive, and less often used, mainly for specific applications like welding.
HOW IMPORTANT IS AN EXPERIENCED OPERATOR FOR OXY-FUEL CUTTING ON A CNC TABLE?
In years past, with less sophisticated CNC machines, the skill and experience of the operator was an important factor in the productivity of the oxy-fuel cutting CNC table. On these older machines, it was critical to have the “know how” to get the preheat flame just right, before piercing, without looking at gauges. You had to have the “know how” to fine-tune the flame to deliver the best quality cut edge, without looking at cutting charts. But that skill set just doesn’t exist in the market, as readily as it once did. But, that’s why CNC automation has helped make operators with less experience, get up to speed more quickly with these new modern oxy-fuel cutting systems. Today, an operator can enter the parameters of the job, like material, thickness, and cutting tip size, while the gas pressures are set automatically, and the cut is calculated by the CAM software. The user control interface and programming software is very important and reduces the time needed for an operator to become proficient with the oxy-fuel cutting technology and start producing quality parts without a lot of supervision.
CAN THE OXY-FUEL CUTTING CNC TABLE ALERT THE OPERATOR WHEN SOMETHING LIKE CUTTING TIPS NEED TO BE REPLACED?
An oxy-fuel CNC cutting table still requires a good technician or table operator to identify when consumable sets need to be changed. Like plasma cutting, where an operator can see that large fluctuations are occurring with the voltage, which is indicative of problems with the consumable set, this type of occurrences also exists with oxy-fuel technology. An experienced operator is still needed to notice things like an abnormal oxygen stream or cut edges that don’t look right. If so, you don’t have to buy an entire torch tip if it needs to be replaced, because consumables come as a set, with two to three pieces, so you might need to replace only one part of the cutting tip. An experienced operator can determine this. For instance, an outer shield can be replaced if too much spatter is on it, as only an operator can notice that.