This won't be anything new to you more experienced scrollers but for those newbies and oldies like me, this is newfound info. I had read about doing this somewhere here on SSV but had never really done it until today. I had installed a new Pegas #5 MG blade and tensioned it the same way I always do. But something was just not right after cutting for just a short bit. The blade was acting funny. So, I released the tension lever and the blade had a big arc in it as if it was too long. So, what I learned is, install the blade, tension it, run the saw for a minute or so and then retension it. I was amazed at just how much the blade had stretched. When I install a blade, I always pull down on the upper arm and then tighten the clamp screw. Then pull the tension lever to apply the actual tension. This is the first time That I have ever noticed the stretch in the blade. Amazing.