Some Qs came up some time ago regarding these drill sets, with most comments being pretty favorable (including my own), esp considering the price: $20-39, TiN coated, etc. 135 deg point (above 1/8, iirc), but with 3/8 shanks, above 3/8.
My main criteria was longevity, and they seem to last OK, overall quality/case seemed decent. Never thought to check them via measuring the holes they drilled.
I was form tapping 5/16-18 holes, which requires an L drill (.290), and after some peculiarities with the inserted set screws, I determined that the drilled holes were coming out at .304 -- !!!! Holy shit...... WITH spotting!! In a Fadal!!!!!
AND, the drill actually does measure 290!!!
How does a .290 drill that actually measures .290 drill a .304 hole?????? With no ostensible wobble, or other defects.
And yet, some bit sizes drill close to their size, so you cain't even*predict* the error. The problem *seems* to be particularly bad on the letter drills, judging from previous travails that I had not pegged to regularly errant bits.
Just an fyi.
I guess the moral to the story is, You don't always get what you pay for, but if you don't pay, the odds much much less..... like an effing accurate hole, ferchrissakes.
And, of course, I have a *bunch* of these drill sets..... I guess I'll use them to drill clearance holes for screws.