Sizing bearings for elevators and telescopes

[Richard_Wallace]

@CarlosGJ

In aerospace, we need things to be reliable, so we use standard parts.

As one who left the automotive industry to join an aerospace company a couple of years ago, I resemble that remark.

Seriously, both industries have their standards. National Aerospace Standard (NAS) parts meet very stringent quality requirements, and their pricing reflects that.

Quick example: 1/4-20 x 1" Alloy Steel SHCS, corrosion resistant

Aerospace part (NAS1352-4-16P): 92562A271, $3.67/EA
Non-aerospace part (ASTM B117): 91274A172, $0.24/EA ($11.98/box of 50)

Oh, and metric NAS parts actually are a thing.