When it comes to hooks, R50 is the center of the world. R50 represents THE STANDARD:STANDARD LENGTH and STANDARD WIRE DIAMETER. This is the hook all other hooks relate to for comparison of shank length (Extra Long/Extra Short) and wire diameter (Extra Heavy [Strong] / Extra Fine). The letter "R" indicates that the hook has a Rounded bend, and the letter “C” indicates that it has a curved shape. Simple as that!
R30 is 2 Extra Fine (compared to R50). The first digit "3" indicates that it is "2 Extra Fine" compared to the standard that starts with "5". For lighter Dry Flies. R70 is 2 Extra Heavy. The first digit "7" indicates that it is "2 Extra Heavy" compared to the standard that starts with "5". For stronger hooks and nymphs.
R72 is basically the same hook as R70, but the second digit “ 2” indicates that the shank is 2 Extra Long (70 + 2 = 72)
R74 is a 4 Extra Long version of the R70. All other parameters, such as wire diameter, gap, etc, are identical. Get it? If you are looking for a shorter hook than the standard, you subtract from "70".
R48 is 2 Extra Short (compared to R50). All other parameters are identical. (50 minus 2 = 48)
C49S is 1 Extra Short (compared to R50). The diameter of the wire is identical. If there were a R49, it would have had the same length and diameter as the C49.
POSITION OF THE EYE, COLOR/COATING OF THE HOOK, AND SPECIAL FEATURES
A most important message from the market, fly tiers and fly fishermen was to "Make it simple". We have decided that the R50 is the standard. Also, "Bronze"(brown) is the standard color and "Turned down eye" is the standard position of the eye.
R50 is bronzed and has a turned down eye. Since this is set as the standard, we do not describe it in further detail. However, if the hook has another color/coating or a different eye position it will appear from the AlphaCode.
C49S has a straight eye. The letter "S" is added after the digits, to describe the hook as a straight-eye version. (Curved, Standard Diameter/1 Extra Short, Bronzed, Straight Eye).
C47S D includes the letter "D" to describe that the hook is "Duratin" coated. Duratin is a silverish corrosion-resistant coating for saltwater applications. (Curved, Standard diameter, 3 Extra Short, Straight Eye, Duratin).
S71S SS starts with the letter "S" to describe that it has an O'Shaughnessy shape. The hook is 2 Extra Heavy/1 Extra Long, has a Straight Eye, and is a Stainless Steel hook.
The Popper hook CK74S SS is a hook with a special feature: It has a Kink in the shank. Still, reading the AlphaCode should not be a problem: It is Curved, Kinked, 2 Extra Heavy, 4 Extra Long, Straight Eye, Stainless Steel.
All Signature hooks are totally consistent in gap-to-length ratio. The gap of a #12 R50 is the same as the #12 of an R30, R70, R74 or an R90. The smallest #28 looks exactly like a big #2. You will find total proportionality in all sizes. And you know what? So is the case in the insect world!