# Drilling HA



## jhanko (Dec 17, 2006)

I'm thinking about drilling a 1.8mm hole in a black HA head for a panel dot LED. The LED is to be mounted on the inside of the head and the dot flush with the outside. Is it possible to drill this hole without the anodizing chipping? This is one of my favorite heads and I don't want to do it if there's going to be chips around the hole. Thanks,

Jeff


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## Mirage_Man (Dec 17, 2006)

JHanko said:


> I'm thinking about drilling a 1.8mm hole in a black HA head for a panel dot LED. The LED is to be mounted on the inside of the head and the dot flush with the outside. Is it possible to drill this hole without the anodizing chipping? This is one of my favorite heads and I don't want to do it if there's going to be chips around the hole. Thanks,
> 
> Jeff



I just got done cutting the HAIII off of all the tail cap contact areas on the [email protected] in my GBs. Some have _tiny_ little chips others don't. I think it's pretty insignificant, and I'm really anal. :laughing:

As for drilling? I don't know. Is it a Mil-Spec HA? I wouldn't tell you do it or not. But if you do make sure the bit is as sharp as you can get it. Good luck!

MM


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## Anglepoise (Dec 17, 2006)

The HA will not chip.
However to get a really nice hole, drill a pilot hole first and then the final one.
Also to make sure the drill bit does not wander, some sort of center punch should really be used to make a small indent.


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## cmacclel (Dec 19, 2006)

I have had HAIII and regular HA chip from slotting and boring. The Black Mags are like 10x harder than the colored units and the Anodizing chips easy. HAIII is 10x harder than the Black mags and has also chipped on me.

Like TB said make sure you have a brand new drill bit. Also as Anglepoise mentioned a center punch may work and would most likely be mandatory if your drill by hand. Try it out on the inside of the tailcap first.

Mac


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## greenLED (Dec 19, 2006)

Just to set the record straight (again) since Al hasn't showed up:
Aluminum lights usually have Type II or Type III anodizing. Type III is also known as Hard Anodizing (HA); "regular HA" or "HAIII", or even "HA3" are improper terms.


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## highorder (Dec 19, 2006)

I was wondering how long that would take... anodizing needs a lawyer.


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## greenLED (Dec 19, 2006)

highorder said:


> I was wondering how long that would take... anodizing needs a lawyer.


:laughing: More like a devil's advocate... 

I imagine you machinists would cringe if I called a lathe tool post a chuck (or something like that), and I'd welcome the chance to learn the proper nomenclature.


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## highorder (Dec 20, 2006)

its all in the verbage; you can chuck something in a chuck. if you scrap it, it gets chucked.


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## greenLED (Dec 20, 2006)

highorder said:


> its all in the verbage; you can chuck something in a chuck. if you scrap it, it gets chucked.


I see, but how much wood would a woodchuck chuck, if a woodchuck could chuck wood?
:lolsign:


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## highorder (Dec 21, 2006)

it depends on what he charges for custom chucking...


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## TranquillityBase (Dec 21, 2006)

> Like *TB* said make sure you have a brand new drill bit. Also as Anglepoise mentioned a center punch may work and would most likely be mandatory if your drill by hand. Try it out on the inside of the tailcap first.


 
HEY! I thought I was TB...:huh2: :goodjob: 

OK...I'll be Brian for a while,

MM..............

Mac[/QUOTE]


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## will (Dec 21, 2006)

Sometimes you are better off drilling with the final size drill in one shot. The 'point' will keep the drill bit from wandering or chattering. Now if you are using a drill press and a solid vise, then the two step approach is fine. It also depends on the final hole size.


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## highorder (Dec 21, 2006)

for precision work, I always use a center drill first. the short length and thicker shank acts like a spotter drill ensuring proper hole location. past that, the use of a pilot hole/ final drill size is a function of material, setup rigidity, bore depth, and final hole size.


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## jhanko (Dec 22, 2006)

Thanks for all the advice. I am still confused however. I assume that the anodizing (BTW, this is a black HA Surefire KL4 head) is harder than a high speed steel drill bit. If that is the case, what happens when the bit attempts to shave it off? Does it just crack off in tiny pieces or can the bit actually cut it? If not, what about a solid carbide circuit board drill bit. Would it stand a chance of "cutting" it? Thanks,

Jeff


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## Tritium (Dec 22, 2006)

Type III is a Mineral coating (Aluminum Oxide, AKA Corundum AKA Saphire) that penetrates the surface of the aluminum. To drill saphire you need to grind through it. Lubricated diamond would be best to peneterate the Aluminum Oxide layer then a good sharp bit for the bare aluminum. Lapidary supply houses carry diamond bits for drilling of minerals although you can make your own by coating a stiff piece of copper wire slightly smaller than the hole you want with olive oil and then rolling it in raw 240 grit diamond boart (powder) making sure to press the diamond into the copper surface in a rolling fashion. For the cleanest hole go SLOW!


Thurmond


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## PhotonFanatic (Dec 23, 2006)

JHanko said:


> Thanks for all the advice. I am still confused however. I assume that the anodizing (BTW, this is a black HA Surefire KL4 head) is harder than a high speed steel drill bit. If that is the case, what happens when the bit attempts to shave it off? Does it just crack off in tiny pieces or can the bit actually cut it? If not, what about a solid carbide circuit board drill bit. Would it stand a chance of "cutting" it? Thanks,
> 
> Jeff


 
Well, if you switch to a carbide drill, then they would definitely be harder than Type III anodized aluminum:

_*Solid Carbide Cutting Tools*

__The cutting edge hardness of carbide ranges from 77 to 81 HRC. Solid carbide cutting tools, such as drills and end mills, are thermally stable and offer high resistance to abrasive wear._ 

As I recall the Rockwell hardness for Type III is close to 65 HRC.

Your better HSS drills will have a Rockwell hardness of 63-65 and Cobalt drills will be 65-67.

Of course there are also diamond coated drills, too. Nice hit to your wallet, though.


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## 65535 (Dec 23, 2006)

I would say drill a hole about 1-2mm smaller than you need like 1/16th-1/8th then use a dremel with tungsten carbide bit to widen it should come out nice if you are carefuly.


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## highorder (Dec 24, 2006)

anno is so thin this conversation is purely acedemic.

65535, why would you opt to finish a hole by hand, giving up the rigidity of a machine setup? have you the hands of a surgeon?


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