Re: Favorite penetrating oil that DOESN'T STINK!
"The only way I find to get a proper metric is to "
Actually, I bought a couple of little tools last year that I keep kicking myself in the ass for not having boughts a thousand years ago. Thread pitch tools.
Anywhere from $5-20 each, available in metric, english, and beware if there's no label because there are Whitworth as well.
It looks like a little fold-up set of allen keys or feeler gauges, like a little pocket knife. Except each "blade" has a set of teeth cut into one or booth edges, each in a different thread and pitch. So if you hold a bolt against the blades and "1/4x20" matches up, or "8mmx1.5" matches up, whatever it is, it really is.
On the higher priced side of things, they also are sold like a "necklace" where the pearls are different sized nuts. Again, whatever nut fits, that's your thread. (And vice versa, strings of bolts to check your nuts.)
The Home Despot and other places have been kind enough to put "size finders" like that one the hardware shelf, but it is so cheap and easy to just buy the damned things and have them in the tool box. I think Vermont American is one of the inexpensive brands, just an inch long and that's good enough.
Which of course still doesn't help with generic imported junk metal parts that were made on worn out dies for the lowest price.