quote:

Originally posted by jimmy123x:
First off, a $30 set of drill bits are not exactly high quality. You can get a very good quality set IF you know which ones are good.....ie Makita, Dewalt, Milwaukee's $30 sets are pretty good.

First off, if you had bothered to click the link in OP you’d see they’re not $30 drill bits (got for better price than current $55 price Amazon) and reviews on Cobalt drill bits on multiple sites they’re well rated (better than anything you listed).

quote:

Originally posted by jimmy123x:
That being said, he shouldn't have chipped the drill bits going from 3/16 to 3/8" drill bits. I'd send them back. I've drilled all kinds of metal and put drill bits through all kinds of abuse, no oil, etc. and have never chipped any except once. I have dulled drill bits yes, but had pieces fly off the first time or 15th time I used them, no. It's poor metallurgy.

I concur

quote:

Originally posted by shiftyvtec:
3/16" is thicker than I expected.

That’s why I mulled on it for a while. I knew my 25 year old titanium coated bits from Costco weren’t up to the task.

Lately, I’ve been buying specialty Irwin bits (eg 3/4” ship auger) for projects around the house and almost went with their M35 cobalt bit set but this Bosch set was M42 and better reviewed.

quote:

Originally posted by tatortodd:

quote:

Originally posted by jimmy123x:
First off, a $30 set of drill bits are not exactly high quality. You can get a very good quality set IF you know which ones are good.....ie Makita, Dewalt, Milwaukee's $30 sets are pretty good.

First off, if you had bothered to click the link in OP you’d see they’re not $30 drill bits (got for better price than current $55 price Amazon) and reviews on Cobalt drill bits on multiple sites they’re well rated (better than anything you listed).

quote:

Originally posted by jimmy123x:
That being said, he shouldn't have chipped the drill bits going from 3/16 to 3/8" drill bits. I'd send them back. I've drilled all kinds of metal and put drill bits through all kinds of abuse, no oil, etc. and have never chipped any except once. I have dulled drill bits yes, but had pieces fly off the first time or 15th time I used them, no. It's poor metallurgy.

I concur

They're $32.98 at LOWES. But, send them back. I think they're overhardened and made them brittle and defective.

I had a Dewalt titatnium set that was gold and silver colored that were phenomenal, put them through tons of use and abuse, probably bought them 10 years ago and still have remnants of the set and they were around $30. Sadly Dewalt doesn't sell them anymore. I went with a Milwaukee set that's gold in color and they work very well. But the Cobalt Makita set rates very high also.


https://www.lowes.com/pd/Bosch...l-Bit-Set/1000549733

those are not quality bits I would bet they are made in china, either way by yourself a grinder and watch a few you tube videos. I rarely if ever use cutting oil with a 3/8 hole I probably wouldn't even have drilled a pilot hole.

quote:

Originally posted by jimmy123x:
They're $32.98 at LOWES. But, send them back. I think they're overhardened and made them brittle and defective.

You're wrong. Again. You really ought to stick to boating issues.

They are higher-cobalt bits meant to be used in a drill press, just like my Walter Surface Technologies SST drill bit set. If I used my DP bits the way TT used those Bosch bits I could not be in the least bit surprised if I chipped one--or even snapped it if/when it snagged. But, in a DP, they'll go through spring steel without dulling--without lube, because they're very, very hard.

He needed jobber bits and he needed to use them correctly.

My DP drill bits, tested:



Link to original video: https://www.youtube.com/watch?v=4dFmnjEzeeQ

 
I use Champion Brute Force Platinum bits for everything up to 1/2". I have managed to dull some due to incorrect usage. Once I got a mill/drill, and learned about rotational speed (rpms), feed speeds, and a generous use of cutting oil, I can now drill steel with my VSR cordless or corded hand drill and the bit stays sharp. Yesterday I was drilling 8 holes in 3/8" steel (my workbench top) with a hand drill, sizes for M8 and M12 bolts, with no problem. If you watch the waste coming off the bit, that gives a big clue about your speed and feed. It should produce a nice spiral piece of metal, not chips.

I was eyeballing Champion Brute Force Platinum drill bit sets since they’re made in USA. I saw that Champion recommends mechanic length (XL28) over jobber length (XL5) for cordless drills. They’ve also machined flats in the XL28 for chucking in cordless drills. Also, looks like they’re made from M7 high speed steel (molybdenum added to M2 HSS instead of cobalt to be less brittle than M35 or M42).

My next and final safe to drill and anchor is much thinner gauge so I’m going with a TiN coated HSS step bit. Also, bought some tap magic like PowerSurge recommended.

I've had a set of Champion XL28 bits for years, got it from Amazon. One of the best sets I've ever had, although I will qualify that by saying I haven't ever spent a ton of money on a set of bits. The container is great too.

I've no dog in this fight, I'm just remembering that in the past, when a post like this came up, the professional machinists would jump in and say they are named Drills, not drill bits. LOL.

That is all.
.

quote:

Originally posted by OKCGene:
I've no dog in this fight, I'm just remembering that in the past, when a post like this came up, the professional machinists would jump in and say they are named Drills, not drill bits. LOL.

True. And the thing that makes 'em spin is a drill motor, not a drill