First let me say that while I do have some connection with UNI Products
I have no financial relationship with the company.
The world of threads became very confused a few years ago when certain
companies began putting X/0 numbers on their threads which bore no
resemblance to any recognized criteria. Benecchi was one of the
offenders. That said, one must ask what is the material of the thread.
Benecchi 12/0 and Griffith 14/0 are the INDENTICAL thread to UNI 8/0 -
same diameter, same strength. They are all polyester threads from the
same original manufacturer.
The Helms article has numerous errors, mostly due to the measurement
methods (I was a mechanical engineer in a former life). If someone has,
or receives, this chart and wants examples of errors, email me off-list.
The best way to understand thread sizes is to look to the spoolers like
UNI and Wapsi that give the Denier measurement of the thread. Denier is
the weight in grams of 9000 meters meters of thread. So, for example,
UNI 8/0 is 72 denier, 6/0 is 135 denier. This is not perfect because the
weight will vary with material; so a Danville nylon thread will have a
different denier number than a polyester thread (but not by very much)
even though both may have the same effective diameter. Diameter is very
difficult to measure directly because most measurement devices or
methods have some effect on the material itself, and most materials
aren't prefectly round - like an untwisted nylon thread - so diameter
has no real meaning in these cases.
Gel-spun Polyethelene (GSP) threads are stronger for the equivalent
denier but are of course more expensive. For example UNI Cord 12/0
(similar to Dynacord Superfine) is a 50 denier GSP thread which is even
stronger than UNI BigFly, a 400 denier polyester.
Waxed threads are weaker than the unwaxed version - that is because
every operation on a thread weakens it somewhat. So, just like any
others, unwaxed UNI 8/0 is slightly stronger than waxed UNI 8/0.
I'll be pleased to answer any additional questions about threads.
Cheers,
Paul
--
Paul Marriner
Outdoor Writing & Photography. Member OWAA & OWC. Author of Atlantic
Salmon, Ausable River Journal, Miramichi River Journal, and Modern
Atlantic Salmon Flies.
