Metric vs SAE hardware

[BBray_T1296]

If you dare to mix hardware, be VERY sure to label metric and sae hardware/tools differently. Like opposite sides of the room. Paint metric tools blue and SAE red or something.

Hex keys are almost cross-compatible, but can strip bolts. Same for wrenches (though those usually are easy to tell what size they are). Nuts are not compatible but somebody will try... see troubles with swapping nuts on main breaker and old PDB lugs. You generally had to trash the whole PDB when that happened. (not sure if the new one is different?)

[asid61]

Originally Posted by BBray_T1296

If you dare to mix hardware, be VERY sure to label metric and sae hardware/tools differently. Like opposite sides of the room. Paint metric tools blue and SAE red or something.

Hex keys are almost cross-compatible, but can strip bolts. Same for wrenches (though those usually are easy to tell what size they are). Nuts are not compatible but somebody will try... see troubles with swapping nuts on main breaker and old PDB lugs. You generally had to trash the whole PDB when that happened. (not sure if the new one is different?)

McMaster sells metric screws with a blue coating. On the rare occasion you have to use metric, go blue.
We paint our metric allen keys red, and imperial keys yellow.

[Chief Hedgehog]

Originally Posted by BBray_T1296

If you dare to mix hardware, be VERY sure to label metric and sae hardware/tools differently. Like opposite sides of the room. Paint metric tools blue and SAE red or something.

Hex keys are almost cross-compatible, but can strip bolts. Same for wrenches (though those usually are easy to tell what size they are). Nuts are not compatible but somebody will try... see troubles with swapping nuts on main breaker and old PDB lugs. You generally had to trash the whole PDB when that happened. (not sure if the new one is different?)

Agreed. Too bad that FRC/VEX/AM suppliers went SAE... So yes, you will be purchasing double the drivers/wrenches/etc. However, the positive side it is a great lesson on the power of a base 10 system!

[timytamy]

I'm going throw a completley biased opinion in and say Metric.

We've been standardised on metric out of neceesity, but even then we've never had great dificulty with intrerfacing with AM/VEX etc. It's true you need a second set of tools for many things, but I've found that more than enough socket, spanner and allen key sets often come with both Metric and SAE sizes anyway.

Don't stress too much about mixing bolts, in fact, stripping out a screw head can be a very good leason in using the right tool - not just the one that fits! That being said, you don't want that to happen at a competition!

[GeeTwo]

In addition to standardizing on a measurement system, I would also advise standardizing on a thread pitch for each size. A couple of years ago, we tossed out almost all of our 10-24 hardware. We're using 10-32, because of how much AndyMark makes use of this thread, but coarse threads for other sizes, which are certainly easier to get locally.