When pins get hot

I was having issues with stainless pins getting too hot as well, only recently though, learned much here. My problem was switching to 300 stainless from 416 a few knives back. Now strictly using 416 and much better, used a magnet since I mixed it all up, pulled all the 416 to top of pile (thanks MTBob).
 
Here's some thoughts on using aluminum pins:
- AL comes in a range of alloys from really soft to kinda hard - from 20XX to 70XX designations, indicating relative tensile strength
- Soft aluminum is gummy, and 60/70XX series are harder. A simple file test will indicate just how gummy or hard the material is. But, unless marked, it's impossible to know the precise alloy.
- 6061 T6 is a common, relatively "harder" alloy and is used widely in the aircraft industry and is easily machined
- Grinding aluminum on a dry belt (like we mostly do on a 2x72) will load up the belt with metal, fast - no matter what the condition of the grit is! 6061 T6 is more forgiving. Grinding on a full spray wet belt will float the aluminum off the belt and minimize loading.
- All aluminum is soft and is prone to scratches, not desirable for producing a high polished pin finish. Though I'm not sure if 6061T6 is softer than brass or silver alloys.
- Aluminum is a highly reactive element and quickly will "fog" over with an oxide, losing it's sheen - and is subject etching from acids - like in fruits & vegetables. Adding a protective covering will minimize the oxide film, but that is often impractical on a knife.
- I've seen various companies that make a cast aluminum handles with great success. My impression is that those knives are more of a utilitarian camp tool, not intended for kitchen or high end markets.
No doubt aluminum pins are used successfully, but for the above reasons, I'm inclined to not use them as long as I have other, better, choices.
Just my thoughts... and, as always, I could be wrong.
 
MTBob said:
Here's some thoughts on using aluminum pins:
- AL comes in a range of alloys from really soft to kinda hard - from 20XX to 70XX designations, indicating relative tensile strength
- Soft aluminum is gummy, and 60/70XX series are harder. A simple file test will indicate just how gummy or hard the material is. But, unless marked, it's impossible to know the precise alloy.
- 6061 T6 is a common, relatively "harder" alloy and is used widely in the aircraft industry and is easily machined
- Grinding aluminum on a dry belt (like we mostly do on a 2x72) will load up the belt with metal, fast - no matter what the condition of the grit is! 6061 T6 is more forgiving. Grinding on a full spray wet belt will float the aluminum off the belt and minimize loading.
- All aluminum is soft and is prone to scratches, not desirable for producing a high polished pin finish. Though I'm not sure if 6061T6 is softer than brass or silver alloys.
- Aluminum is a highly reactive element and quickly will "fog" over with an oxide, losing it's sheen - and is subject etching from acids - like in fruits & vegetables. Adding a protective covering will minimize the oxide film, but that is often impractical on a knife.
- I've seen various companies that make a cast aluminum handles with great success. My impression is that those knives are more of a utilitarian camp tool, not intended for kitchen or high end markets.
No doubt aluminum pins are used successfully, but for the above reasons, I'm inclined to not use them as long as I have other, better, choices.
Just my thoughts... and, as always, I could be wrong.
Click to expand...
So, when you want silver pins, you use those 309L Tig rods you mentioned earlier? As a newbie, I'm surprised that lots of folks use brass rods as pins, but when you start asking about silver pins, I'm not seeing a clear answer? Am I wrong about that, or maybe the answer is nickel silver?
 
KentuckyFisherman said:
So, when you want silver pins, you use those 309L Tig rods you mentioned earlier? As a newbie, I'm surprised that lots of folks use brass rods as pins, but when you start asking about silver pins, I'm not seeing a clear answer? Am I wrong about that, or maybe the answer is nickel silver?
Click to expand...
Brass looks great against a dark handle, especially as it oxidizes and turns darker. I use brass and stainless in both rods and tubes. As everyone says, fresh ceramic belts are your best friend on stainless after you use a bandsaw to cut them flush to the scales. Don’t just grind 1/4” of pin stickout to make it flush. It will be hot as fire and burn your epoxy. That’s how you get that dark circle around your pin called “mooning”.
 
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