Best Type of Drill Bits from McMaster or Otherwise?

I am looking to source some drill bits for our robot shop.

All the ones you get at the hardware store are for the most part junk.

Next year, I’d like to buy some “good” ones. I see McMaster has a whole list of different kinds. Which type of drill bits work best for your shop?

Or is there some other magical place to get drill bits? I prefer NOT TO PURCHASE a set, because there are a few sizes that it’s just good to have about 10+ on hand because everyone uses that size.

PS: I am good with software and electrical, not drill bits…lol…

Chris,

I find that most drills get beat up due to in proper use. Speeds and feeds are important when using a cutting tool. It doesn’t matter if your buying HSS (high speed steel) or some type of high end coated drill. If you run them too fast, too slow, out of round or without evacuating chips, they will fail. Sadly this is what happens during a season. Especially when hand drilling.
That said, an Industrial supplier will sell packs (like 10 per) of specific size drills. For most robot work standard HSS is fine, look for jobber length (also a standard).
Another option, especially for sizes over 1/8" is a sharpener. DrillDoctor is an easy to use effective device that will sharpen a wide variety of sizes and make them ready for more abuse.

Good Luck.

I just googled the “drill doctor”, thanks for the TIP! Might have to try that too next season.

To dreictly answer the OP - high speed steel jobbers bits are great for 90%+ of FRC applications. If you do a lot of wood drilling look into these bits: http://www.mcmaster.com/#standard-drill-bits/=whoexm and if you do a lot of plastic drilling, particularly in brittle plastics, check out these bits: http://www.mcmaster.com/#standard-drill-bits/=whof9y and for sheet metal and thin materials I like to use dedicated sheet-metal bits and/or step drills. Still, all of that said, it’s hard to go wrong with high speed steel jobber bits for everything.

I would like to second the drill doctor. It can do a great job of keeping drill bits in good shape for a long time.

As with anything else in the shop: drill bits will treat you the way you treat them. Here are some rules that our team uses to keep drill bits functioning well. This is in addition to the good practice of looking up feeds and speeds for bit sizes and materials!

Rule 1: When drilling by hand use 1st gear for steel and 2nd (or 3rd) for aluminum. Overheating (usually when drilling steel) is the #1 cause of dead drill bits in my experience. Heating softens the drill bit material, causing it to dull very quickly. Dull bits heat up faster… it’s a nasty cycle.

Rule 2: When drilling metals use a cutting fluid. There are numerous fluids that can be used for this, and you can spend a lot of money on them, but almost any oil will be better than nothing! In my garage I use whatever engine oil is handy, on the robotics team our shop has dedicated cutting oil. Just a bad will do ya. If this oil smokes, slow down and/or stop for a while (see Rule #1).

Rule 3: Pilot drill (almost) everything! The center part of most drill bits (the chisel) doesn’t actually cut material, it pushed material out of the way. Pilot drills are usually sized just a little bit larger than the chisel of the bigger bit. Thus pilot drilling keeps larger bits cutting efficiently and reduces heat buildup. This is especially important when drilling by hand, when a person can’t exert enough force to let the bit cut effectively if the chisel is engaged.

Rule 4: If the bit slips in the chuck get a coach or someone stronger to tighten the bit, and if you see damage from slippage file it down. This keeps bits spinning true. A wobbling bit is a sad bit.

Rule 5: Hand drills are always set down on their sides. I’ve seen many bits snapped off from a drill that tipped over. This can also knock the chuck off-center, which will cause issues when drilling.

Hope this helps!

Definitely get Jobber length bits for most of your drilling, and for sure buy a bunch of bits in whatever sizes you use most often. Also, it’s a good idea to stock up on number (not fractional) bits for drilling and tapping with properly sized holes.

There are also two drill bits that have come in big and saved our team on more than one occasion. Keep in the shop and travel with, in addition to regular bits, a few really long drill bits (usually 12"-16") long in standard sizes (3/16", 1/4", etc). Note, they also come in a chip-clearing variety that you might like as well. They don’t have to be fluted all the way, just enough to drill through a few inches, but they are immensely helpful in drilling holes in hard to reach places. This tool is something that I have used at literally every competition I’ve attended while working in the pits, and it is something that most people don’t think about. You might consider a right-angle drill set to reach difficult places as well.

For economy, the Harbor Freight TiN coated big set is hard to beat. I own several, and my personal set at home has served me over a decade, including lathe use. It includes letters, fractions, and numbers up to 1/2 inch. The index case is junk though.

For aluminum, bright finish HSS is preferred. A US-made set from a reputable manufacturer like Hertel will serve you well, but it will cost you. We have sets of screw machine length drills that are really nice. Most times, you are not drilling very deep.

You may want to invest in a set of drill dispenser drawers from Huot. They are available on Amazon Prime or McMaster, and very worth the price.

As a final note, I treat many drills as a consumable. I don’t allow dull drills to remain in our shop. For dull drills under 3/8", I throw them away.

Another GREAT TIP! Thanks, I just googled this and I think that will help keep all the drill bits organized better. Thank you.

We have mounted a triangular piece of sheet metal to the bottom of all of our hand drills so that they can no longer be left standing upright. Takes the kids a while to get use to this. The next issue is that they want to leave them on the edge of the table where they are easy to knock onto the floor…

My team essentially has two drill bit sets- the huge Harbor Freight TiN coated set that has every bit imaginable, and a box of extra bits in the common sizes- 1/8, 5/32, 3/16, 1/4, etc as well as all of our extra taps and the drills that go along with those. We use 3 or 4 sizes for 90% of our drilling, so we order 10 or 15 extras of these sizes from McMaster at the beginning of the season. Basic HSS for all of the extras.

Agree with others that bits are “supplies”, not “tools.”

We were happy with bits we bought from MariTool this year. I also personally bought this index from Aircraft Tool Supply to have a set at home.

Reducing the number of fastener sizes helps you reduce the range of bits you need to maintain. We ordinarily use #8 machine screws, with occasional use of #10, #6, #4, and 1/4" screws.

These bits we buy in quantity, as we will use up several of them in a build season:

#16 (free fit for #8 screw, our most popular bit by far)
#7 (free fit for #10 screw)

These bits we have a couple of each:

#25 (free fit for #6 screw)
#30 (free fit for #4 screw)
#29 (tap for #8 screw)
#21 (tap for #10 screw)
17/64 (free fit 1/4" screws)

Note that there is only one fractional bit in the bunch.

I plan to move to this container for storing the common bits next year.

We have one of these that is filled up to 3/8" for miscellaneous tasks.

This season, I just got sick and tired of seeing students struggle with our cheap A$$ harbor freight drill bits, that I went ahead and purchased 4 of each of the following from McMaster and we keep them in a separate storage container, labeled and all (including what it is used for)… These are all the clearance and tap sizes for most popular screws from #6 to 1/4" as well as 1/8", 5/32", and 3/16" for rivets.

We still have a full 115 pc harbor freight indexed set, but that’s just for special jobs.

2901A174 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 3, 3-3/4" Oal, 2.18" Drill Depth, 135 Degree Point

2901A21 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 36, 2-1/2" Oal, 1.3" Drill Depth, 135DEG Point

2901A203 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 29, 2-7/8" Oal, 1.5" Drill Depth, 135DEG Point

2901A202 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 28, 2-7/8" Oal, 1.5" Drill Depth, 135DEG Point

2901A198 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 25, 3" Oal, 1.7" Drill Depth, 135 Degree Point

2901A194 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 21, 3-1/4" Oal, 1.9" Drill Depth, 135DEG Point

2901A192 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 19, 3-1/4" Oal, 1.9" Drill Depth, 135DEG Point

2901A182 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 10, 3-5/8" Oal, 2.14" Drill Depth, 135DEG Point

2901A178 Black-Oxide High-Speed-Steel Jobbers’ Drill Bit, Wire Gauge 7, 3-5/8" Oal, 2.13" Drill Depth, 135 Degree Point

2754A45 Clog-Resistant Uncoated High-Speed-Steel Jobbers Drill Bit, 1/8", 2-3/4" Overall Length, 1.4" Drill Depth

2754A47 Clog-Resistant Uncoated High-Speed-Steel Jobbers Drill Bit, 5/32", 3-1/8" Overall Length, 1.7" Drill Depth

2754A49 Clog-Resistant Uncoated High-Speed-Steel Jobbers Drill Bit, 3/16", 3-1/2" Overall Length, 1.9" Drill Depth

2754A54 Clog-Resistant Uncoated High-Speed-Steel Jobbers Drill Bit, 1/4", 4" Overall Length, 2.3" Drill Depth

2754A55 Clog-Resistant Uncoated High-Speed-Steel Jobbers Drill Bit, 17/64", 4-1/8" Overall Length, 2.3" Drill Depth

Screw machine (or “short length”) bits are the way to go for most FRC applications. More rigid, don’t wander off center, usually cheaper. Echoing the others: you want uncoated or bright finish for aluminum.

From McMaster:

Heat-Resistant Cobalt Steel Short-Length Drill Bits
Heat-Resistant Cobalt Steel Jobbers’ Drill Bits

We use the harbor freight 115 piece cobalt steel set. The bits rip through everything we throw at them.

100% agree, we originally bought a couple screw machine lengths drills for our CNC machine so we wouldn’t have to center drill low accuracy parts. We ended up using them for everything. They are much easier to line up than a long jobbers length drills when using handheld drills and we very rarely need anything longer.

No need for Cobalt. HSS is fine.

eBay and Shars (I haven’t had any problems with their USA bits). Unless you really train the users on determining proper speeds and technique, buy cheap ones and buy a lot of them :slight_smile: Buy the sizes you need in bulk - there are several sizes I’m sure you won’t need regularly so keep only a few full sets. I find screw machine / stub lengths work best for most work.

I apologize for bump an old topic from the dead, just have a few interesting observations from personal experience, maybe someone will need this information in the future.
Depending on the material that you are drilling, HSS is probably your best all around choice.
For plastic, aluminum and light guage steel the price/longevity ratio is tough to beat.Between fabbing stuff 5-10 times a day for the trucks at work, and general use (drilling through firewalls, extracting stuck bolts, etc), I use my bits pretty much everyday. From my experience:

  1. Cobalt is best, but a good HSS bit is fine if it’s from a quality source. I bought a set of bits (1/16 -> 1/2 by 64ths) off one of the tool trucks at work. Ran ~$180 for the set, but the bits are warrantied for breakage, so as long as you keep them sharp it’s a reasonable investment.
  2. Keep them sharp. Most drill bits aren’t as sharp as they could be, even out of the packaging. Learn how to use a bench grinder, or even better, a drill doctor (but get one of the higher end ones that will do split points).
  3. Split points for metal is the way to go. Keeps the bit from wandering.
  4. Use cutting fluid. It keeps the bit cool and prolongs the life of the bit. Heat kills bits.
  5. Let the bit do the cutting, not pressure. Apply just enough presure for the bit to work, any more than that and you are dulling the cutting edge of the bit. It sounds simple, but most people don’t do it.I used to drill quite a bit of stainless while working offshore (mostly 10 ga or less). I did not find any bits that would do it “easily”, Cobalt bits Irwin https://mechanicguides.com/best-cobalt-drill-bit-sets/ tend to be better. Slow speed and heavy feed pressure with ample coolant will do the job, which means that you need a drill press with appropriate speeds. If you have to drill with a portable drill, keep the speed VERY slow and press HARD.
    Stainless tends to work harden so you must keep cutting through the hardened layer every revolution, if you let up on the feed for an instant, the hardened layer will be too thick and will ruin your bit.