Wednesday, October 31, 2007

Thickened Edge Flighting Review

I recently took a look at some testing done by an accredited agency in Canada regarding the durability of thickened edge flighting versus traditional helicoid style flighting. Following is an article I wrote in regards to that.

The Myth of Thickened Edge Flighting

"Up to 50% thicker", "longer life augers", "improved wear resistance", are the features the manufacturers of thickened edge flighting tout as advantages over traditional helicoid style flighting. However, are these features actually fact and advantage, or is thickened edge flighting simply marketing hype?

First one has to understand what traditional helicoid ribbon style flighting is. Traditional helicoid style flighting is flighting rolled from a rectangular piece of steel to create the flighting, or "auger part" of the auger in a long, unbroken, ribbon. To produce this flighting, the traditional method of production rolls flighting that is thicker at the base, or core, than it is at the outer edge. So, if you say, "10 gauge flighting," generally speaking, you are talking about the flighting thickness at the base, where it is welded to the center flighting pipe. This is how flighting has been produced for the grain handling industry for many years.

Recently, thickened edge flighting, also known as Super-Edge or Dura-Edge amongst other names, has been introduced and promoted as an improvement on this process. Thickened edge flighting is helicoid style flighting rolled in such a manner as to leave a thicker strip of material at the outer edge of the flighting. The intended purpose of this thicker strip along the edge is to give you more material where flighting wear is normally most apparent. Sounds like a good idea right? Add more material to the edge for more wear? Unfortunately, it seems, this is not necessarily an advantage.

A study conducted by an independent, accredited, agricultural testing agency compared traditional helicoid style flighting and thickened edge helicoid style flighting. The findings were somewhat surprising.

A metallurgical report on the steel of both respective types of flighting was done. Breaking down the numbers into a manageable format that the average person can understand, the traditional helicoid style flighting tested as using a harder base material than the thickened edge flighting's material. Additionally, the report refers to differences in the "work hardening" at the edge of both flightings. The thickened edge flighting product showed less work hardening at the outer edge of the flighting than the traditional flighting. Specifically, the thickened edge tested at a softer 91-91, versus the traditional flighting at 95-95. Presumably, to accomodate the manufacturing process of leaving more material at the edge of the flighting, the thickened edge flighting has to be rolled from a softer grade of steel, and because it is "worked less" at the edge to leave the remaining thickened band, it is less dense at that point.

A mechanical test to identify differences in the durability of the traditional and thickened edge flighting was done by running identical flightings, with the exception of the edge type, in aggregate for 85 hrs. Visually, after running for the same amount of time, it was very difficult to tell the difference between the two flightings. Beyond the visual, weighing the flightings showed that the thickened edge flighting actually lost material 10% faster than the traditional flighting when compared on a weight basis.

So, what does all this testing mean? Essentially, this is a case of perception, marketing perception. Considering the information mentioned above, thickened edge flighting offers no real, definitive advantage over traditional helicoid style flighting. Realistically, one could point to subtle points of superior wear characteristics for the traditional flighting. So, if you are paying more for, and expecting more life out of your thickened edge flighting, you may be disappointed.

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