| Breaking In a Blade...
I have not heard of or seen much discussion regarding a method of breaking in a blade properly to improve its durability.
I'm relatively new to fencing and have only gone through a few blades and have routinely been putting the appropriate bend in a new blade and then using it. I'm wondering if theres a better way to insure that blades last as long as possible.
To back up a bit, I have considerable experience doing metalwork as a sculptor, welder and machinist. I have a fair working knowledge of metalurgy as regarding tempering and heat treating some common alloys.
In my work I follow a specific proceedure for installing and breaking in a new bandsaw blade in a metal cutting bandsaw. Typically these blades are called "Bimetal", meaning that the portion of the blade that encompases the cutting teeth are of a different metalurgical composition than the rest of the blade, referred to as the "back." This allows the manufacturer to make the teeth harder to better hold their sharpness at the risk of making the material more brittle and prone to failure. The remainder of the blade is "softer" and more ductile, providing flexibility and toughness to withstand the tension and twisting forces required to support the teeth. To break-in a bandsaw blade properly it is first run at very low tension - just enough to keep it from slipping off. then the tension is gradually increased and a few easy cuts in relatively soft material are made. The idea is to slowly subject the sawblade to increasing loads. Once the maximum tension is reached and a few cuts in harder stock are made, the blade is ready for work, cutting at full tension, speed and horsepower.
I have observed first hand the importance of this break-in. Without break-in I have had new bandsaw blades fail on the first heavy cut. With break-in they can last quite a long time.
This behavior could well explain why some people report that FIE blades do or don't last longer - perhaps depending on the type of initial use they were subjected to.
I have also observed that in my foil & epee blades, that a) they tend to get "softer" with time, and b) that sometimes they develop soft spots where they bend more and need to be re-straightened after each hit, and invariably break near that spot when they eventually fail.
This behavior is consistent with my understanding of how blades wear - on a microscopic level. Repeated stress in metal - at levels approaching the yield point, which is where permanent deformation occurs causes minute "micro-cracks" to form between the planes of the mineral grains of the steel. In a fencing weapon these "fault" lines will form on the convex side of the blade, oriented perpendicular to the length of the blade. Ideally, with a well broken-in blade the distribution of these features should be uniform and proportional to the cross sectional thickness along the section of the blade that takes the bend and absorbs the hit. This makes for a even, gentle curve in the blade, and a gradual distribution of the force of the hit within the blade itself.
If however, you get your new blade, stomp on the foible a few times and then go fencing with it, the first "oops-too-close-sorry-you-ok?" hit you make puts a kink in the blade, which even after straightening results in a concentration of microcracks in that zone. Thereafter, with every hard hit it bends a little bit more in that spot. Repeated straightening by reverse overbending in that spot only contributes to the accelerated fatigue in that zone.
If and when I buy some new blades I plan to try a version of gradual break in as described above, perhaps some easy target hitting first before "taking it to the strip" If the experiment is successful, I should have a longer lasting weapon that requires less straightening during a bout.
Anyone have thoughts on this? Links or references? Do blade manufactures do any testing / research in this area? Do they NOT tell us more, to keep replacement blade sales moving?
Art. | 
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