Sandflex® Bi-metal machine saw blades 3809 Suitable for all materials Sandflex® is a virtually unbreakable bi-metal saw blade. Saw blade that does not splinter and can withstand high feed pressure and cuts accurately, quickly. Sandflex® Saw blades are safer in all conditions, even on old machines or less experienced users. Correct blade tension is essential to ensure a straight cut and a long life of the blade. If the tension is too low, the blade bends up or twists the blade, causing high tension, excessive wear on the blade and uneven, crooked cuts. Excessive tension causes high stress in the blade and saw frame General rule for harder materials; a lower stroke speed and higher feed pressure are required If the chips are burned, the feed pressure is too high If tooth cracks appear, the feed pressure is too high Fine, powdery chips indicate that the feed pressure is too low Fine, curled chips indicate the optimal feed pressure The teeth should not touch the workpiece when the machine is started A useful rule of thumb is that at least three teeth should be meshed together at the same time