Drill bits

[Mark m]

I bought a set of small drill bits on Amazon.

 

I measured the bits, and found that the sizes were mostly incorrect, and that 2 or 3 supposedly different sizes were actually identical.

 

In searching the MSW forums, I saw similar complaints about other vendors.

Now I’m looking for better quality bits.  Is there a good brand or supplier I should look to?

 

[glbarlow]

I’ve been in this search for a long time and have a drawer full of junk bits.
 

I like this set mostly because there are multiple ones of each size I typically need and because they are sharp and durable enough to do the job…until they aren’t and I reach for another one. 
 

 

[bruce d]

Hello Mark,

Sorry to hear yet another tale on this subject. There are plenty of good suppliers out there but it would help to know where you are since this affects which suppliers are relevant.

 

Bruce

 

[Paul Le Wol]

Hi Mark, your question got me curious so I measured some drill bits that were bought online from a Canadian hobby shop. They are made by Excel. 
I used digital calipers.

 

#71 measured to be  .64mm/ .025”.  Charts  indicate they should be .66mm/ .026”

 

#72 measured to be .61mm/ .024”.   Charts indicate they should be. .635mm/ .025”

 

So I guess we have to measure them no matter who makes them

 

[BenD]

I've had a set of Microbox drill bits for years now and have yet to break one. They are still really sharp even after drilling brass and copper. The set I bought were also very accurate in size.

 

I bought mine at Cornwall Model Boats. You might be able to find the same on amazon, but supporting our hobby shops is worth the extra $10.

 

https://www.agesofsail.com/ecommerce/20-pce-microbox-drill-set-(modelcraft,-0.3--1.6mm).html

 

https://www.cornwallmodelboats.co.uk/cgi-bin/sh000001.pl?WD=drill&PN=rdr4001%2Ehtml#SID=1121

 

[bruce d]

1 hour ago, BenD said:

supporting our hobby shops is worth the extra $10.

 

👍

[allanyed]

If you reside in the US or maybe Canada try

https://www.mcmaster.com/drill-bits/   You can get them down to 0.006" diameter.    These are not cheap at the smallest sizes, but they are excellent quality. 

Allan

[Mark m]

12 hours ago, bruce d said:

Hello Mark,

Sorry to hear yet another tale on this subject. There are plenty of good suppliers out there but it would help to know where you are since this affects which suppliers are relevant.

 

Bruce

 

I travel around the US and Canada.  Often nowhere near a good hobby shop, but I prefer in-store when I can.

[mgdawson]

15 hours ago, Paul Le Wol said:

#71 measured to be  .64mm/ .025”.  Charts  indicate they should be .66mm/ .026”

#72 measured to be .61mm/ .024”.   Charts indicate they should be. .635mm/ .025”

So I guess we have to measure them no matter who makes them

Hi Paul

Drill bits often 'drill' a fraction over their measured size so the .02mm might be deliberate, good luck measuring the hole 🙂

Mark

[allanyed]

7 hours ago, Mark m said:

20 hours ago, bruce d said:

 

I travel around the US and Canada.  Often nowhere near a good hobby shop, but I prefer in-store when I can.

It is sometimes possible to find adequate quality bits at the smallest sizes in a hobby shop, but if you really want high quality bits you need to get them from an industrial supplier, like Grainger or McMaster Carr et al.  I used to go to the MM distribution center and warehouse in NJ in person when I bought these kinds of things, but I am no longer in short range of such distribution centers.   Maybe there is an industrial supplier near you.  https://www.grainger.com/category/machining/drilling-holemaking/drill-bits/drill-bits-for-metal-plastic?attrs=Drill+Bit+Size|%2380&filters=attrs  which has several 0.02" (#80) bits is one more example.  Again, they are not cheap, but they work.

Allan

[wefalck]

This is another recurrent discussion ... as Allan said, if you require high accuracy and long useability, then you might to go to either an industrial supplier or a watchmaker supply house. However, there you will have to pay a bit more. I am not sure about that, but I would suspect that hobby suppliers can only maintain their prices by buying lower quality or 'seconds', i.e. drills from reputed manufacturers that did not meet their internal quality requirements or that of their customers.

 

Grinding sub-millitmetre drills is quite a challenge and may result in quite a lot of 'seconds'. In general, they are ground from calibrated 'drill-rod', so that the shank is the nominal diameter. It is here where diameter should be measured. In fact, such drills may cut slightly oversize holes, because the cutting edges may not be exactly centred.

 

The most exact drills with respect to running true are those with thickened shaft. They are made with 1 mm, 1.5 mm, 3 mm and 3.2 mm (= 1/8") shaft.

 

If you are drilling by hand, you are quite certain to end up with an oversize hole. Nominal diametre holes in the sub-millimetre rand can really only be achieved with a pillar-drill or similar and collets (chucks normally have to too much run-out).

 

So at the bottom line, I would not worry too much about the drills not being exactly the nominal size. Pick a drill that matches the material for which you are drillng the hole for.

[Roger Pellett]

Most cities of any size in the US have branches of national industrial supply houses.  Names like McMaster Carr and Grangier come to mind.  You might try places like these.  I personally use the eyeball system for selecting drill bits smaller than #60.  If it looks like the right size it’s OK.  .001in is an order of magnitude smaller than my working tolerances!

 

Roger

 

 

[Charles Green]

To the list of industrial suppliers, I will add MSC Industrial Supply for any type of drill bit or circular saw blade.  MSC has a UK division as well.

[GGibson]

I purchased the set of Microbox drill bits that BenD showed in his post (mine are in a blue plastic box with a clear sliding case), but I also purchased a nice set of Gyros drill bits that have worked well for me. Gyros® Carbon Steel Wire Gauge Mini Twist Drill Bit Set |Includes 20 Micro Carbon Steel Bit Sizes #60 to #80 | with Convenient Clear Dome Storage Case (45-12010) (gyrostools.com)  

[allanyed]

 

The Gyros set is also available at Micro Mark under the Rodgers name as well as many hobby shops and hardware stores under various names.  I used them in the past and found them to be OK for wood but dull or break very quickly on brass.   The big plus is they are cheap compared to good quality bits. 

Allan

[glbarlow]

My bet is the the ones in the sliding plastic box are mass produced and just have different resellers games printed on them, I have a bunch of them, they don’t last long. Same with the “Gyros” box, though they’ve lasted a little longer.  

Edited August 27, 2022 by glbarlow

[bartley]

I like Kyocera bits.  They are expensive but are very precise and very sharp. Also they all have the same shaft size so changing bits is a breeze

 

Edited August 28, 2022 by bartley

[mtdoramike]

I just go by Harbor freight and buy their cheapo mini wire drill bits, yep, they break, yep they aren't true to size, but they are plentiful, cheap and just down the road from me. I've had $60.00 sets of mini to micro drill bits and found no difference in performance, however they do cut quicker when you first get them, but they quickly dull like they all do. 

[glbarlow]

On 8/28/2022 at 2:37 PM, bartley said:

Kyocera bits.  T

I got some of these, they broke so fast and so easy I tossed them. Glad your experience is different.

[mnl]

On 8/25/2022 at 10:36 AM, Paul Le Wol said:

Hi Mark, your question got me curious so I measured some drill bits that were bought online from a Canadian hobby shop. They are made by Excel. 
I used digital calipers.

 

#71 measured to be  .64mm/ .025”.  Charts  indicate they should be .66mm/ .026”

 

#72 measured to be .61mm/ .024”.   Charts indicate they should be. .635mm/ .025”

 

So I guess we have to measure them no matter who makes them

 

 

You are within 0.001” with a pair of calipers. Have you checked it with a standard? That to me is a pretty good measurement. You need to be using a micrometer, and if you are measuring to that level of precision you need one that will read to 0.0001”, something like Brown and Sharpe, Starrett, Mitutoyo, or Elaton. Even with those measuring exactly across the flutes is hard.

 

As far as quality goes, McMaster, MSC, Travers are all fine. Anything you get from any of them will be fine. If you are planning on drilling 316 stainless or Ti all day then selection matters. Do not buy carbide unless you have a CNC machine, you will only break them.

 

Lastly, all drill bits flex and wander, so the hole will be larger than the drill, even if the flutes are perfectly ground. To get a minimum size hole you need to spot with starting point exactly concentric to the drill body. Most drill chucks are not concentric at that level, except maybe a small Albrecht chuck. Both the spotting drill and the drill need to be held in the appropriate collet. The feed pressure on the drill also needs to be just right so that it cuts, but does not have an excess bending moment.

 

 

[Paul Le Wol]

8 hours ago, mnl said:

You are within 0.001” with a pair of calipers. Have you checked it with a standard? That to me is a pretty good measurement. You need to be using a micrometer, and if you are measuring to that level of precision you need one that will read to 0.0001”, something like Brown and Sharpe, Starrett, Mitutoyo, or Elaton. Even with those measuring exactly across the flutes is hard.

 

 

Hi mnl, you are correct, I made too many assumptions.

[bartley]

On 8/30/2022 at 12:24 PM, glbarlow said:

I got some of these, they broke so fast and so easy I tossed them. Glad your experience is different.

Yes Glenn,  one thing that is very important is the quality of the drill press.  Many of the cheap ones "precess" ie the move like a spinning top.  This will break drills real fast.  So in such a case, as many have said. a better approach is to buy cheap ones and live with the breakages.  Incidentally, my Dremel on its stand does this but the Proxxon drill press is good.  I may have just bought lemon for the Dremel!

Edited October 17, 2022 by bartley