Reply With Quotethe dark copper colour may not be stainless steel
sounds more like phosphor bronze, which normally has a reddish brown colour when it gets old. looks goldy-red when freshly machined.
Hi guys, any metalurgists out there? Just wondering why some of the stainless pinion gears in some of my reels are a silver colour and some look like dark copper colour?
Is it the hardening process that changes the colour on the dark ones?
the dark copper colour may not be stainless steel
sounds more like phosphor bronze, which normally has a reddish brown colour when it gets old. looks goldy-red when freshly machined.
Yes, I know what you mean, but the reels that I am refering to, are supposed to have a stainless pinion gear. The darkest one is in my PENN Torque 200 and it has been that colour from new.
I am not a metalurgist by any means, just a sheety who works with stainless. From my experience stainless will go brown (tea stain) when it corodes, have never seen it go a dark copper colour, though it will depend on the materials that make up that particular alloy of steels. If it were that colour from new it may well have been heat treated to strengthen it.
what colour is it on the teeth where it is worn from tooth to tooth gear contact?
If it is shiny silver in the little wear marks, then it is stainless.
If it is reddy brown, or goldy prown, it is phosphor bronze
surface colour from heat treating is only a couple of microns thick and will quickly wear off
Some of the lubricants can stain metal too.
If the gear has be titanium nitrided it will be a goldy colour.....do they nitride stanless?
A nitrded surface is suposed to be harder and have less friction..
cheers
Its the details, those little details, that make the difference.
Thanks for your replies fellers. I will have to wait until this reel has done a bit of hard work to find out. It is very new and has not been put under any load yet.
if they do that, it is normally only on the gear teeth area, not the entire component.Originally Posted by oldboot
could it be thats its only 304 and not 316??
304 and 316 look very similar to the naked eye, can't tell the difference if just 2 raw bits of metal
Whats the name of the reel, someone might know it already.
It would be doubtful for the pinion or drive gears to be made from either 304 or 316 stainless as they are not suited to gear applications. There are some 150 different types of "stainless" steels, and not all of them look silvery even when polished. Some are magnetic, some not, some corrode in salt water, some not, some disolve in a particular acid and others will not in the same environment. Some are designed for anti-wear and some are designed to be sacrificial.
The whole point is these items could well be a form of stainless steel, but that grade does not need to be one you are familar with as yet. In the metalurgy feild there are some 1200 different "common" metals used in manufacture, yet we see less than 2% of these in a year as common consumers.
Working out what stainless steel your gears may be made out of would be best asked of the manufacturer as testing procedures to determine the grade will most likely involve some form of destructive testing.
Jack.
Posting Permissions
