I am building a workbench in my new garage, and decided I would like two hunks of bowling alley as my work surface. From the first 40' of the alley, making it all very dense maple hard wood. I started searching and found two 11' sections about 180 miles away. Called the guy and he only wanted 25.00 ea for the sections, so I solicited some help from my son and drove out to pick them up.
These things are very heavy, each one was well in excess of 350lbs. We loaded them up and headed home.
So now time to cut these 11' X 36" X 2" chunks into my soon to be work bench surface. This required making two pieces one 9 - 1/2' X 27" and one 7' X 27". My Skill saw already had an Irwin 7-1/4 24T Carbide blade in it so I used it to make my first cut, taking off 36" on one end. I worked from the back side screwing a furring strip to use as a guide. The cut was nice and clean, even though I did cut four nails in half and two the long way. I figured for the long cut I would put on a new blade, as I was aware this was tough stuff and sure to be nails every six to eight inches all the way down the full length. I went to my local hardware store and picked up two Marathon Carbide 7-1/4 X 24T blades, same as what was already in the saw (So I thought!).
I put on one of the new blades and started my long cut, about one third the way, after cutting through a few nails I noticed the blade was not cutting and in fact was warping or becoming soft and kind of going its own way. I stopped and examined the blade, all the carbide tips were gone! So I changed to the other new blade and started cutting again, with the same experience. After another third of the way the blade was trash, teeth gone! I went to switch back to my original blade and noticed the only difference was the blade that was originally in my saw was made in New Zealand vs. the blades that failed were made in China. I put the old blade back on and finished the cut, hitting many nails along the way, but all the teeth were still in place, the blade looked like new!
It was clear, the blades from China were junk. I went back to the hardware store and found all the blades were made in China; DeWalt, Irwin, Chraftsman, ACE, in fact they all looked like they came out of the same factory. In flipping through the stock, way at the back I found two Irwin Marathon 24T Carbide blades NOS (2005) made in New Zealand. I purchased both of them.
Now time to cut the long cut with the (New) New Zealand made blade. As expected, one blade made the full 11' cut, going through many nails along the way and it still looks like new!
When will these Companies learn? The package states made in China to Irwin Specifications; so did the New Zealand blades, but clearly, there is a major difference between the quality of the blades from New Zealand vs. the blades from China!!