Only 5.3% of US welders are women. After years as a professor, I became one

> One man, watching me while I cut 8-foot lengths of tubing for him, told me that I could simply hook my tape measure over the saw blade and subtract ⅛-inch to find the correct length. Piqued after I explained why his method wouldn’t work for a precise measurement, he responded by quizzing me on something I wasn’t likely to know: the purpose of the black diamonds on my tape measure.

Perhaps I'm picturing the situation wrong, but why wouldn't it work on the precision levels of a tape measure?

The most obvious reason is if your blade isn't 1/8 inch (3.17mm) thick.

If you're cutting with a bandsaw - the blade is a lot thinner than that.

And if cutting with a circular saw, the cutting teeth are wider than the main disk of the saw, which complicates matters - and I can't imagine it'd be easy to keep the tape measure hooked on either.

And of course - subtract 1/8 inch? Are you sure you don't mean add 1/8 inch? If you're learning a clever new technique, better to practice on some scrap, not do it on a customer's material while they're watching :)

At the higher level, saws have no undo function. Cut an expensive bit of metal too short? Someone has to pay $$$ for new material. Buddy on another machine did a load of work on the part before you cut it too short? He's going to have to redo it all. Who'll pay for his time? The stock you cut too short was on a long lead-time or urgent project? You just fucked up the schedule.

So if a machinist is doing some work for you and they want to measure twice and cut once - they're doing you a favour :)