Drill bits and tolerances

George, I miked 3 drills in the set. 23/64 tip .359, shank .358; 9/32 tip .281 shank .279; 11/64 tip .172, shank .171. I looked at the bottom of the stand and it is US. Each drill is stamped RUSSIA HSS Co. I found a label I stuffed inside the stand "Gary Twist Bits item 40455 M25, 21 pc. I am 99% sure it was an HF buy as I have never sought out online drill mfgrs. Don't know how many years ago. No sku comes up on HF or elsewhere on line. Mysterious?

571.JPG
 
I have never seen Russian tools for sale,so I have no experience with them. Of course any modern,or upcoming country like China CAN make tools just as good as anyone would ever want. The low price we want to buy those tools at is what holds their quality down. I think everyone realizes that. If you've gotten a superior set of Russian drills I think you've done well. I'd like to find some of those myself ! Unfortunately,my closest HF store is too far away to make regular visits to.
 
Well, the western Russias are butting on Poland and think I have seen a lot of ?end mills" from there. When I bought these drills I was dubious. I believe the brand "Gary" is probably as in Indiana? So maybe there was once an arrangement. Anyway I wish we could all still get these in HF as their selection seems to leave a lot to be desired.
 
I just noticed that Hemly machine Co. has USA made 115 pc. screw machine length drill sets(shorter than the usual ones,but how often do you drill a really deep hole). They start about $181.00 Cobalt is about $236.00. I rounded the prices off a bit. They seem like they will be good buys of decent quality drills. They have 29pc sets,too.
 
Hi

I have various drill sets along with individual drills bought in packs/boxes of ten from various sources here in the UK ...usually on Flea bay but also from some other 'drill specialists' most of them are made in China anyhow & will usually be of the 'rolled' process not ground. I check each drill with a Vernier Caliper as the sizes are not to be trusted e.g. a 3mm drill will often measure out at 3.1 or even 3.2 which is not what you want for small holes, so now, to ensure I get the hole size I need I use one or two sizes less e.g. 2.8 / 2.9, (as measured not stamped) as they usually end up being 3.1 ( tho' I ream out if still undersize ). I measure them at the cutting tip as this tends to be larger than the shank, I also roll them on my surface plate as they will invariably be out of true so you'll see the tip wobble up & down so I use these for general drilling with a good centre pop starter or centre / spotting drill.

The only drills I would consider of any worth here in the UK are... Presto or Dormer (UK) or Guhring (German)... usual disclaimer, no connection other than a satisfied customer... as these are usually 'ground to size' but they are vastly more expensive than the normal Machine Mart / B&Q (UK), HF / Home depot (US) Chinese supplied drills)... e.g. I recently bought a pack of 5 x 2.6 drills (Chinese) for £2.70 ( US$4.22)... compared price for a 'Presto' - 1ea... £3.69 ($US 5.77)... a 6x difference per item ...Guhring ...pack of 5x 2.5... £6.95 ( 10.86 US) a factor of x12 per item... :angry: so it is really a case of you gets what you pay for, what I'll be doing from now on is as I'll use up what I have then replace with Guhring / Presto / Dormer.. as my pension will allow, never the less enjoy & have fun.

George.
 
I got a 115 bit set of the HF bits which have been pretty good for average jobs, when I break one, I get a name brand to replace it. If I need a hole that close, I ream it...oh and many name brand are now made offshore so just because it once was a "made in the USA" brand, does not mean it is now. TIm
 
Before I started buying quality drill bits, I didn't know any better and would buy Bosch cobalt drill bits,
which, it turned out were pretty good bits! Then I started buying other bits from MSC, McMaster-Carr
and Grainger. I like Chicago-Latrobe USA bits and then started buying Guhring. The Guhring drill bits and
end mills are excellent. I also buy Keo for countersinks and center drills. I think it's good to buy from different
manufacturers and try them. I only buy USA and Guhring now and have settled on a few names that I like and trust.

I also check my bits, Mic, calipers and I drill test holes in scrap steel. So now, I know if I want a tight fit for my bolts, i.e.
I will use and "undersize" drill, D letter for 1/4" tap bolts, 25/64" for 10 mm threaded rods, etc... Everything has a tolerance.
So I experiment and test, then test again. Check, measure and make notes. Thank you all for the great info.
 
I bought a 115 piece tin coated set Grizzly last year on their president's special. I think it was $45. It's been a good set. There are a few that I used constantly and finally broke. When that happens I run down to Marshalls and by a 6 or 12 pack of US made bits to have on hand in sizes I frequently use. If I need accuracy my small reamer collection will increase by one.

Dave
 
I just remembered I saw a company once that did end mill grinding for one of the larger supply company's. the company was in the USA and the tools were sold as Made in USA but it was only the grinding done in the USA. The cutters were actually from another country. I can't recall if the tools arrived partially ground and were just finished or if they were completely ground here. Could be done with drills as well though.
 
They ought to only say "assembled in USA" like some products say,or something similar if only ground in USA.

For some reason inside my head,I think it is just safer to buy separate fractional,number,and letter sets. That is what I've always done. They certainly are more portable to where you're working.
 
You must log in or register to reply here.
Back
Top