Years ago I got a box full of resistors and other components, all new. A lot of them are grey colored resistors, 6 band with a tolerance of 1%. The problem is that they aren't what they should be. 390 ohm resistors for example give a reading between 400 and 430 ohm. I double checked with two different multimeters and then checked the color code which says it should be 390 ohm. (color code: orange, white, black, black, brown, red.) Even if brown accidentaly is gold then the resistor still should read max. 410 ohm.
If it were a few I wouldn't even ask and threw them away already, but I have hundreds of these things and certainly don't feel like measuring them all. Throw them away anyway or am I missing something?
The 5th band is brown which is 1%, silver is 10%. I even used my wifes reading glasses as a magnifier to make sure I didn’t mix up the colors. I guess it’s a flawed batch, maybe that’s why I got them for free.
Knowing that they are off the tolerance you might use them for less precise applications like current limiter for LED, there is not much danger using 410Ω instead of a 390Ω
However, considering you’ve got a lot of them you might think about to donate them to a local hacker/maker space. They will be more than happy to take it as they always need some community stuff for free.
I did a quick search and found a Dutch non profit organisation which teaches children and teenagers a thing or two about electronics and computers. I’ll contact them as soon as I’ve measured the other odd grey resistors. (I have a whole lot of them in different values.)
