D/F Machine Specialties machine-held water-cooled TIG torches or GTAW torches are designed to meet the stringent and continuous demands of precise, high-amperage mechanized welding applications. The D/F Machine Specialties TM500-CN (Tube Mill) Top Load TIG Automated Machine Barrel is intended for semi-automatic or automatic machine applications of the tungsten inert arc process. The barrel accommodates top load of tungsten with a tubular dual collet design providing clamping pressure at two points.
The TM 500 Machine Torch Series features a heavy-duty 500 amp water-cooled power cable. This water-cooled automated TIG barrel has the unique feature of the nozzle assembly water passages being serially connected to the inner body water chamber by means of sliding removable connectors. This allows ease of maintenance and eliminates the use of o-rings or gaskets in the water passage system.
D/F Nozzles (also called gas cups) provide a given amount of shielding gas coverage to the weld pool, according to their size (anywhere from 1/4- to 5/8-inch ID). For example, a smaller nozzle provides less gas coverage than a larger one. Nozzles also vary in price and performance. Built-in gas lens/gas difussor improves gas coverage to eliminate shielding gas turbulence and improve weld quality (all models). The TM 500 Back Load TIG Torch is available in 12.5" barrel lengths to meet exact welding requirements on precise mechanized jobs. Front or back tungsten loading/tightening eases tungsten changeover and extension adjustments (all models). Internal tungsten adjustment eases fine positioning of tungsten and allows for axial movement of 1/4 inch (all models).
With the optional Tungsten Advance/Retract Attachment (D/F #42205) you can actually adjust the arc length by changing the height of the tungsten in 1/2 inch increments through 5 inches of the 7-inch tungsten. This attachment is only made for fine adjustments, and when the tungsten needs to be either replaced or sharpened, you can pull out extension shaft and the tungsten for only these purposes. If you ball up and contaminate the tungsten you have to take off the gas cup and use a tungsten cutter and cut off the ball and then you can pull it out. The advanced retract is made to withdraw the tungsten to be re-sharpened or replaced, not when it has been balled up. If this is used properly, the tungsten should not be contaminated because you have the fine adjustment. Standard consumables interchange with all D/F TIG torches to lower inventory costs. These heavy-duty model TIG torches withstand the most demanding high-amperage applications.
The most cost effective are 90 or 95 percent alumina oxide nozzles, which work adequately for lower amperage applications. These nozzles, however, do not resist thermal shock on higher amperage applications very well and tend to deteriorate or crack and fall off.
Lava nozzles cost more than alumina oxide nozzles and are more resistant to cracking. These nozzles work well on medium to high amperage applications.
The bottom line when choosing TIG consumables is to look for factory OEM parts that provide you with the durability and performance you need. A wide variety of options exist for back caps, collets and collet bodies, gas lenses and nozzles, all of which offer distinct advantages, disadvantages and cost considerations. For less critical applications, the less expensive alumina nozzles provide adequate performance. However, if you need high performance, it is well worth your while to purchase more expensive, long-lasting lava nozzles or cups. Doing so minimizes the chance of consumable failures that could ultimately increase the cost for rework associated with weld inconsistencies.