AFTMA is the Association of Fishing Tackle Manufacturers Association. This is the standardized scale of line weights for each weight of fly rod. The higher the number designation and weight of the fly line the greater the line weight number. The AFTMA weighed the first 28-30 feet of the line and rated each line weight as it appears in the table. At the time of the designation the average angler could cast most efficiently at a distance of 28-30 feet or would most often us this length of line in most fishing situations. This system was established from this theoretical formula to establish the current table of weight tolerances in grains for each line rod weight.
|AFTMA NUMBER||IN GRAINS (RANGE)||IN GRAMS||IN OUNCES|
|3||100 +/-6 (94-106)||6.48||0.228|
|4||120 +/-6 (114-126)||7.78||0.274|
|5||140 +/-6 (134-146)||9.07||0.32|
|6||160 +/-8 (152-168)||10.42||0.366|
|7||185 +/-8 (176-193)||11.99||0.422|
|8||210 +/-8 (202-218)||13.61||0.48|
|9||240 +/-10 (230-250)||15.55||0.55|
|10||280 +/-10 (270-290)||18.14||0.64|
|11||330 +/-12 (318-342)||21.38||0.75|
|12||380 +/-12 (368-392)||24.62||0.86|
Three characteristics influence how well a specific fly line will balance symmetrically with the rod line weight and rod action you have chosen to go fishing with. These features involve the grain weight of the front 28-30 feet of fly line, the length of the head of the line and the dynamics of the taper of the head within that line. Furthermore, these three features within the line (head of the line) must be recognized so the angler can match them with the action of your rod, your casting style and the type of fly fishing you will be participating in most often.
When casting, the rod flexes (bends) under load as the caster moves the weighted mass of the fly line back and forth through the air with the rod hand anchoring the fly line. The angler must distinguish the rod as a flexible lever that works the most proficiently when the balance of line weight to rod weight and flex is the most dynamic. If the angler uses a line with too heavy a line for a specific rod weight the rod will overload and loose its ability to transfer energy efficiently. Overloading the rod will also result in wide open loops that provide loss of direction, less dynamics, accuracy and can even result in sloppy casting. If the angler uses a line that is too light a grain weight the rod will not flex or load properly which will result in loss of distance, efficiency and accuracy in your casting as well.
Bob will go further into detail in his casting program discussing just how important rod, reel and line balance becomes in the overall efficiency in your casting. It also becomes critical towards how gently and accurately you can lay out your dry fly presentations. The rod, reel line balance will definitely result in less angler fatigue and allow the angler to improve their casting stamina. Which in turn will lengthen the duration of each fishing day especially with heavier rod/line weights. Proper rod, reel, line balance will most definitely improve both proper timing and symmetry in your casting as well. The chart laid out by the AFTMA is definitely a tool that anglers need to pay close attention to.
Leave a Reply