Building a flyrod for a saltwater friend. Purchased some 316 stainless snakes to keep the corrosion to a minimum. I know not all stainless is the same (especially far eastern stainless) but should a magnet be able to pick up ss316 guides? These guides were advertised for saltwater use.

Thanks in advance.

TJB

316 is not magnetic.

Some stainless is less magnetic that others, some I've used were magnetic. Haven't had to mess with the magnetic properties as mush as the corrosive properties, so I don't remember as much about it. The 316 stainless has a bit less chromium than 304, the chromium gives the stainless quality which is actually a invisible oxide film that slow more staining drastically but it is more likely to incur chroride damage. 316 has a bit less chromium, a bit more nickel and if I remember right, a small amount like 2 percent, or so molybdenum (hope I spelled it right) which does fight chloride damage much better.

316 Austenetic stainless steel in the passivated state is non magnetic. Parts made of of this alloy may contain trace amounts of free iron unless it has been properly cleaned to remove any surface impurities imbedded by the tooling. The free iron contamination will be magnetic due to the free iron. The proper surface preparation is required in the aerospace industry which includes controlled etching and passivatio[www.azom.com] to establish that "invisible oxide film" referred to above. The precleaning of parts removes the surface impurities which act as sites for chloride attack which cause intergranular cracking. If you have a part that "rusts" the source of the color is free iron and not the base metal. There is some very good information on the All American (vendor to left) site describinhg this corrosion mechanism and the surface preparation required. This alloy improves cold working stress concentration.

See link: [www.azom.com]



Edited 2 time(s). Last edit at 03/14/2010 09:50AM by Bill Stevens.

I've only dealt with 316 in aerospace and marine applications and they are passivated. In laymans terms passivation is a treatment that removes surface impurities that could rust from exposure to the elements. In practical terms you will not be able to feel any attraction with a magnet. It will attract a magnet as much as a piece wood does.

maybe take a look at the Ti guides American Tackle or Fuji

Bill - willierods.com

Slightly magnetic - but more important it will oxidize and discolor. best to go with the REC heavy wire snakes or s/f guides if you want total stain resistance.
Herb

another thing to remember is that when preping the feet of guides. If you use the same tools from on a set of guides that contain carbon steel, then move to stainless you are introducing contaminants into the SS. Which may cause discoloration and corrosion of the surface of the SS.

Herb Ladenheim Wrote:
-------------------------------------------------------
> Slightly magnetic - but more important it will
> oxidize and discolor. best to go with the REC
> heavy wire snakes or s/f guides if you want total
> stain resistance.
> Herb

Whether 316 shows oxidation and discolors depends wholly on the quality of mfg. I've seen 10 yr old 316 SS 1x19 standing rigging on a sailboat that still looked as bright and shiney as the day it was pulled off the spool. Unfortunately the wire was brittle from work hardening and when coiled it broke strands. This boat was cruised heavily for yrs through the pacific, through the canal and then up the atlantic coast so the wire was heavily exposed. The cheaper 316 wire I've used forms a definite oxidation in 2-3 yrs on boats that just sit in a saltwater atmosphere. None of the 316 I've checked has attracted a magnet...and I've checked more than a few marine pieces over the yrs.

I have various rods with "SS" guides and get pretty much the same results as above. Some stay shiney, some get a frosted oxidation (the later mfg guides do this but not the old ones), some get rust specks/stains, some are chrome plated. I've even had foulproofs get brittle and break in the coil. I just checked 9 rods that I put SS guides of varous styles on and none of them attract a magnet. I used the smallest magnet I had for sensitivity...about 1/4" diamenter and 1/16" thick.

bp

Bill,
I stand corrected - maybe. The SS I tested may have been 18-8 SS.
Herb