Oh dear, people never seem to learn. There is no point in buying cheap tooling, even if it isn't complete junk it may have other problems.
Rule 1: Never buy cheap tooling
Rule 2: see rule 1
Many years agoI coughed up and bought imperial, letter, 1-6mm by 0.1mm and 6-10mm by 0.1mm drill sets by Dormer. I think I got them from Greenwood Tools at a big discount on the RRP. Fairly expensive but they last and last. Over 10 years or more I've replaced a couple of dozen. None of the letter drills, one imperial drill because I fudged it on stainless steel, and several metric drills because they wore out, or I damaged the drill or shank. The metric drills are by far and away the most used. The imperial drills are conventional and the metric drills are 4-facet ground. I doubt I'll need to replace the imperial drills in my lifetime. Holes are accurate; I measured a 6mm drilled hole and it was between 1 and 2 thou oversize. The metric drills measure spot on over the cutting edges, as far as I can tell, but the shanks are 1 to 2 thou undersize, ie, they're ground on a slight taper. Presumably that's for clearance.
I can grind drills by hand or on the Clarkson, but simply can't be bothered, the smaller Dormer drills are fairly cheap, and for a few a year it's down in the noise.
I buy special drills as required from Drill Service in Horley. They're mostly slow spiral for brass, left hand for the repetition lathe and carbide for difficult materials like tungsten.
I've got a good selection of larger drills, up to 1-3/4" for use on the lathe to rip metal before boring. They're all secondhand, mostly from Ebay. I don't care if they're odd sizes, like 1-1/64", or drill slightly oversize as long as they drill a hole!
I've also got a set of number drills by Presto that I bought over 40 years, but I use the 1-60 number drills once in a blue moon.
Andrew
Edited By Andrew Johnston on 20/08/2018 21:35:23