Dry Fly Hooks Sizes

Return to an old theme, manufacturer’s hook sizes are really useless.  What you need to know, one you select your hook, is how long is the body. I publish my reference for nymphs six years ago, but not for the dry fly. Given I an updating my dry fly hook standard to the TMC 103BL, so I thought it was time to publish my standard with the associated body length.

• TMC 103BL – Size 11 – 10.3mm
• TMC 103BL – Size 13 – 9.1mm
• TMC 103BL – Size 15 – 8.4mm
• TMC 103BL – Size 17 – 7.2mm
• TMC 103BL – Size 19 – 5.7mm

If I am looking for smaller, for small BWO or Tricos, where I am also thinking about an extended body, I move to the Daiichi 1640 with the Straight Eye.

• Daiichi 1640 – Size 16 – 5.0mm
• Daiichi 1640 – Size 18 – 4.5mm
• Daiichi 1640 – Size 20 – 3.8mm

The body length is define as the from eye (last wrap of thread) to the point where the shank has dropped ~0.66 diameter of the wire. I am not using an optical tool, but measurement by hand with old eyes of one hook with a nice machinist vernier. As such, I would predict the margin of error is about 3%.  (Yes, I am an engineer)

So as illustrated below, yes, I identify the hook, but I look and select the hook by the intended body size.

And what happens to the hooks that fall out of favour (or samples to try). I either:

• Put in a bag in a slot that corresponds to its equivalent. When I tied in the size, I will decide if I will use them up.
• Occasionally sell them or give them away.  This idea of Pay it forward seems like a new way to pass on good karma..

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