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I bought this set of drill bits.

The set came with 3 colours of drill bits:

Silver Gold and Black

I do not know. What does each one of these bit colours mean?

enter image description here

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  • The "gold" on the bits in the middle is 100% marketing wankery. Unless you really know your bits, you can safely assume they're not titanium.
    – JS.
    Oct 5 at 17:21

4 Answers 4

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The tip style of the bits indicates their purpose; the colors mean almost nothing.

The ones on the left are called brad-point bits and are great for going through dimensional lumber. Depending on the region they could be colloquially called auger bits.

The middle are general purpose bits. They can do wood, drywall, plastics like PVC, and possibly metal. Their gold color might indicate that they are titanium-coated bits; at least that's what Milwaukee does. Black general purpose bits are usually black oxide. Different metals indicate different durability.

The ones on the right are masonry bits. They should be used for concrete, brick, plaster, stucco, etc...

Bonus:

Those pointy wide ones at the bottom are paddle or spade bits and are used for boring large holes in lumber. These usually max out at 1-1/2".

In the bottom right are your hole saws.

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    I doubt you'll find any "titanium" bits - TiN coated alloy steel is what's normal, since TiN coating is "gold-colored" and it involves very little titanium as it's a thin sputtered coating - but I'm sure the unethical folks will slap on some other gold-colored coating if they can do it 2 cents cheaper.
    – Ecnerwal
    Oct 3 at 14:38
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    @Ecnerwal Now if only marketing teams were honest on the front of their packaging then we'd all be better off =) i.stack.imgur.com/4qvx3.jpg
    – MonkeyZeus
    Oct 3 at 14:47
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    Agree except that the ones on the left are brad point bits, not auger bits. Auger bits actually have a screw thread on the end that pulls the bit through the wood once the threads have engaged. The brad point helps ensure the bit doesn't wander as the hole starts, and the sharp points at the edge help cut a cleaner hole.
    – FreeMan
    Oct 3 at 15:10
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    @FreeMan Thanks, clarified! I've never made that distinction because it rarely matters. I'm sure the astute woodworker is not buying these all-in-one packs anyways =)
    – MonkeyZeus
    Oct 3 at 15:32
  • also, masonry bits sometimes have red colored tips, which is a special tungsten-cobalt alloy
    – ivan866
    Oct 5 at 0:10
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"It means" at one level, what surface finish was used, if any. Polished steel, black oxide, or titanium nitride (or cheap imitation gold-colored stuff pretending to be TiN)

However, by inspection (looking at the business ends of the bits) I can see that the "silver" ones are wood and/or plastic bits, the "black" are masonry bits, and the "gold" are metal/general purpose bits. For this set, only. All those types of bits can come in any of these colors, but in this set, that's what you've got.

annotated crop of OP's picture showing grouping of bits by color

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    This is absolutely the correct answer, the colours are arbitrary. That being said, the colouring of the box looks like it is either a DeWalt set, or a cheap set using DeWalt colouring to give the imitation of comparable quality at the very least, and the bit colourings are consistent across the brand.
    – ThaRobster
    Oct 3 at 13:46
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    The bits on the left are "brad point bits" ("spur & lip" for our British English speaking friends) and should be used on wood (they'll also work well on plastics). Use on anything else will quickly dull the brad/spur in the center and the lip. They're designed to cut clean holes in wood and won't wander once the brad is placed. The gold bits are "split point" bits and will cut well in wood and in metal. They have a tendency to wander off target when starting, and require a dimple if accuracy is required. In wood, they won't cut quite as cleanly as the brad point bit.
    – FreeMan
    Oct 3 at 15:03
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    Also, to eliminate the confusion, I've added a labeled version of the OP's picture that lines up with what I believe Ecnerwal was referring to. (Please delete if I've misunderstood.)
    – FreeMan
    Oct 3 at 15:07
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    I looked up who made this particular set, and it appears to be an "Amazon Basics" set, so it's pure mystery meat what the bits are made of or who did the actual manufacturing. Oct 3 at 16:14
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    @FreeMan: thanks for the annotated picture, it definitely helps.
    – Martha
    Oct 3 at 16:16
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This isn't a direct answer, but it might be useful. For drilling metal, i recommend cobalt steel bits. Standard high-speed steel (HSS) bits won't even penetrate stainless; they just turn into a glowing blob at the tip. But I use cobalt for all metal; it's just so much easier and faster. As a retired carpenter and fab shop employee, I have been through thousands of bits, and anything but cobalt when working with steel are a waste of time and bits (that you could save to work with wood and plastic). I say cobalt, but there are probably other alloys out there, just use anything but HSS on metal. OH--and please don't confuse cobalt, an element alloyed with steel in drill bits, and Kobalt, which is a brand name at Lowe's. Good luck.

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  • If you have a comment, make a comment, don't post a comment as an answer if it's not an answer...
    – Ecnerwal
    Oct 3 at 22:42
  • Comments are for requesting clarification of the question, not offering tangential advice.
    – chepner
    Oct 4 at 20:02
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Generally the shape of the tip is a better clue than the color to a drill bits purpose.

The bits on the left with a small point are wood bits.

The bits in the middle with a cone shaped tip formed just by grinding the ends of the shaft are general purpose bits. Suitable for materials like wood plastic and metals (though harder metals may be a problem for cheap drill bits).

The bits on the right with a blunt insert at the tip which is wider than the shaft are masonary bits. As the name suggests they are for use in masonary (brick, stone, concrete, plaster etc).

There aren't any in your set, but you also get "multipurpose" bits, which are consturcted in a similar way to masonary bits but the insert is sharper, these are handy when you want to drill holes through multiple materials.

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