Anyone have any info about the tensile strength of size A, C, and D thread? Also, the difference in strength on a wrap between the three sizes? Size A winds on more times per inch than C and D, so theoretically it'll make a stronger wrap.

This informations has been covered extensively in recent months. Try using the search feature provided to aid in your research. It is a very powerful tool and one I use often.

Derek

First of all, unless you are building rods which will have a serious amount of reel drag applied (lets say over 15 # of actual reel drag, not just line test), you are not very likely to have so much force applied to the guide so as to wrench it from its thread wrapping. Most builders and references would say that it takes a good 40+ pounds of static pull on a single guide ring to get the guide out from under a proper wrap.

And it is the THREAD and the tension under which the guide is wrapped that holds the guide in place. The thread finish does practically nothing to hold the guide in place; the epoxy does, however, protect the thread from abrasion and water and that helps keep it from unraveling. It is the friction and pressure of the overlying threads that hold the tag end pulled under in place; the thread finish just keeps it from shifting. That is because the thread finish is a CASTING RESIN; it's ADHESIVE properties are next to nil.


From the GUDEBROD Catalog:

Tensile Strengths for GUDEBROD Rod Thread (# = lbs):
Regular Nylon: A = 2.7#, D = 7.4#, E = 11.6# .
NCP Thread: A = 2.2#, C = 4.6#, D = 5.1# .

Thread Diameters for GUDEBROD Rod Thread (mm = millimeters)
Regular Nylon: A = 0.175, D = 0.260, E = 0.330 .
NCP Thread: A = 0.175, C = 0.260, D = 0.330 .

By multiplying ( 1 / thread diameter in MM) x ( tensile strength in pounds) ,
you will get the RELATIVE wrap strength per MM of wrap width.
If you multiply by 10 (10 mm per centimeter) or by 25.4 (25.4 mm per inch),
you will get units of POUNDS per CENTIMETER, -or- POUNDS per INCH, respectively.

Again, even A size thread is sufficiently strong for almost all applications. Unless you are building the heaviest saltwater rods with drag loads of 40+ pounds, any guide that comes loose is because of getting knocked or smashed. It guide, if hit hard enough can come loose from a violent impact. But usually the guide becomes severely deformed or damaged or the ring cracks before the guide wrap fails.

I hope that helps. -Cliff Hall, Gainesville, FL-

Mark Gordon started a really good discussion of Thread Size & Strength just two months ago. The comments & calculations he made, + the many Replies to him, are really worth reading. -Cliff Hall-

"Thread Break Strength (size A vs D) - debunking the myth"
Mark Gordon 02/19/05 [www.rodbuilding.org]
[http://www.rodbuilding.org/read.php?2,136781,136781#msg-136781]