FI-13sB 13" Fanno Non-Tapered Pole Saw & Hand Saw Replacement Blade. The Fanno name has long been a standard in the Arborist industry and this particular blade is very familiar to most professional arborists. This is a dual purpose blade, for pony or pole saw blades as well as a replacement blade for the Fanno FI1311 hand saw. All at a price to value ratio that makes sense to most arborist businesses. With 6 Teeth per inch, the three sided or tri-edged tooth has edges on both sides and across the top of the tooth. This style tooth cuts much faster than conventional two sided teeth. Impulse hardened using electrical impulses to create a very hard layer on the saw tooth edge. The advantage of impulse hardening is a much longer tooth life, the disadvantage is it cannot be sharpened. This saw blade is punched with two different mounts (hole patterns) to allow one blade to serve as a pole saw blade and at the same time a replacement blade for its respective hand saw. This "Dual" mount allows tree service professional to order just one blade for both uses.