Aggressive flashlight striking bezels

[ApexShootingTactics]

Something we have on our Facebook page. https://www.facebook.com/ApexShootingTa ... =3&theater



I am of the opinion that a flashlight should be part of your every day carry kit. Other than illumination, identification and using the light to disorient a potential threat a flashlight can also be used as a striking tool. The idea behind using a flashlight to strike a threat is nothing new but there is a technique to it and you need to be justified in your actions.

Lights come in various sizes and offer many features. One such feature are bezel options. The bezel is the ridge around the lens and traditionally it's purpose has been to protect the lens from being damaged during use though over the past decade it has been popular to make the bezel with sharp ridges and serrations so when it is used as a striking tool it can cut or tear.

Initially one would think this is a good idea but think about this in greater detail. The vast majority of crimes are drug related, the vast majority of IV drug users have a blood born disease. Cutting them open during a struggle may not be something you want to do. Don't confuse this with using a knife to defend yourself, generally speaking we are looking at two different levels of force. Along those same lines, will a superficial cut really be a deciding factor in such a struggle? I don't think it will. Using a striking tool or impact weapon needs to be about inflicting pain on muscle mass , pressure points or joints. That pain is far more effective than a few cuts. The intent is to inflict just enough pain to take the fight out of the threat or distract them enough to break way or obtain other tools.

In the photo you will see two very aggressive bezels, first on the left and third one from the left. There are several others with very slight ridges and valleys on the bezel. Theses are not considered to be aggressive cutting bezels but are more like vents to allow heat to escape in the event you place a light lens down in a pouch or pocket without turning it off. These gaps allow heat to escape.

So don't get caught up with buying a light that has an aggressive bezel. Worry about lumens, durability and function. Keep checking back for more flashlight tips.

[Brian D.]

Very illuminating post, Andrew ! (Sorry.) Maybe from being in the fire/EMS racket, this had been my thought ever since seeing such a "strike bezel" several years back.

Honestly, the flashlight's general shape is higher on my list of concerns; I hate it when a round sided one rolls off the table and hits the floor, causing the bulb to break. Darn marble and terazzo floors all to heck !

[ApexShootingTactics]

Just trying to shed some light on the topic.

[TSiWRX]

There are several others with very slight ridges and valleys on the bezel. Theses are not considered to be aggressive cutting bezels but are more like vents to allow heat to escape in the event you place a light lens down in a pouch or pocket without turning it off. These gaps allow heat to escape.

Just a quick point of clarification from a confessed flashaholic....

Those shallower scallops/ridges aren't for heat escape. Modern LEDs do not project "forward heat" - heat emitted as infrared radiation, forward of the light. Rather, heat is produced "internal" to the device. The heat-sinks "fins" such as what's seen on the middle, slim light as well as on the light that's the second from the right allows for better cooling of the "star," much as similarly constructed heat sinks inside a computer power unit does. OK, actually, in-truth, those machined areas on the Streamlights probably aren't even "cooling fins," and are probably just styling elements, the old Surefire KL3 head (one of the first commercial "rough use" LED conversion heads) utilized cooling fins:



...and some of Surefire's modern, ultra-high-output lights (Invictus, top, Dominator, below) still do:




For certain lights, their entire bodies help conduct heat away from the LED "star." Lights like the ARC LS, one of the first high-power, ultra-compact/ultra-lightweight handhelds, example, can actually get slightly uncomfortable to hold after being on for extended periods of time. However, if the light was left on, say, on a table top, it'll actually get so hot that you won't want to pick it up. Holding on to it makes your whole body (well, at least your hand! ) the heat-sink.

Back in the days when folks started cranking up the output on halogen incandescents, forward-heat was indeed a very real concern. We have to remember here that at least for the retail market, even as close as 2001, "high-power tactical flashlights" were still in the 60 to 90 lumens range (think Surefire's old P90 and MN03 bulb units; note here that we're not talking about the powerhouses such as the 10X Dominator, M3T, or the M6, which at between 250 to 500 lumens, were designed for serious throw and were too bulky for civilian concealed-carry; and yes, before anyone asks, I still have my old M6, which has for the last few years worn the Malkoff MD60 drop-in, trading throw for run-time and utility in my context, and my old C3 Centurion uses a M91A) - one doesn't have to look much beyond publications such as Ken Good's "The Strategies of Low Light Engagements" to realize how far the technology jumped in those few years between 2001-2004. Back when we were still using halogen incandescents and forward heat was actually a concern, someone came up with the idea of machining a few relief cuts in the bezel not so much as to evacuate heat, but rather, so that we dumb end-users could easily see that we left the light on with the bezel-down, and that whatever we'd set our lamp on was about to get, literally, scorched - if not outright torched.

This is why when you accidentally engage and leave-on a modern high-powered LED flashlight in your pants pocket, your entire upper thigh feels hot, instead of it being a focal burning sensation. That entire flashlight is getting hot as it's getting conducted "backwards." (Sure, the head gets hot, first, as the heat from the star first soaks the heat-sink there and then migrates to the body of the light, and that might cause a bit more discomfort there, but trust me, it's not because of the light being produced, versus a halogen incandescent filament burner. )

So don't get caught up with buying a light that has an aggressive bezel. Worry about lumens, durability and function. Keep checking back for more flashlight tips.

^ This, I agree with wholeheartedly.

That, and heck, your pants (if you carry bezel-down) or your hand/fingers (if you favor bezel up) will thank you!


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For those wishing for a real-world tie-in, the new Cree indoor LED lamps utilize convection instead of conduction for cooling of its star:

http://spectrum.ieee.org/tech-talk/semi ... r-led-bulb" onclick="window.open(this.href);return false;

And I know that some of you have noticed those nifty LED headlamps on Audis (and heck, even the budget Toyota Corolla!). When the R8 first came to the scene with LED headlamps (http://www.caranddriver.com/features/20 ... headlights" onclick="window.open(this.href);return false; and http://www.autoblog.com/2008/05/30/audi ... headlamps/" onclick="window.open(this.href);return false;), we car-nuts and flashaholics marveled at the ingenious design: that the fans which cooled the stars would also port heat to the outer aero covering so as to defrost/defog the light, thereby eliminating that dread effect many of us here in NE-Ohio have seen back when they first introduced LED traffic signals: that snow often blocked the lights' entire output.

[Mr. Glock]

Now that's the Allen we know and love. I have one of the older Pre-LED Surefires that I haven't upgraded. That was the stuff back then, amazing what the same size light can do today.

I never gave much thought to the bezel, so the original post is interesting too.

[TSiWRX]

Now that's the Allen we know and love.

^ I know very little, about very few things. I just happen to be a dorky flashlight collector, whose other hobbies of shooting and things automotive sometimes overlaps.

"Tactical lighting" is, much like automotive winter tires, a "hobby of need" for me.

Technique tips like what ApexShootingTactics have offered above are absolutely invaluable to me. While I might know a bit about the tools, I'm nowhere near as well versed with techniques. Similarly, where it comes to tactics, I probably have only a page or two in the book I'm still working on compiling in my head...and that's why I'm so bummed that I can't make Andrew's class on the night of the 7th ( http://www.ohioccwforums.org/viewtopic. ... t#p4336171" onclick="window.open(this.href);return false; ).

Currently, what I'm trying to wrap my head around is what's the best way to figure out from a flashlight's listed specs (which is problematic in and of itself, given the lack of conformity in the industry) what kind of illumination can be expected. None of the solitary figures of lumen, candela/candlepower, lux, etc. provide the necessary information to judge "brightness" and/or beam pattern and beam throw, which are all critical where it comes to "tactical" applications.

[Klingon00]

My biggest problem with aggressive bezels is they tear holes in my pockets.

[Tweed Ring]

Old school- I use Maglights.

[Bama.45]

Old school- I use Maglights.

I thought you still used a lantern TR

[pirateguy191]

Just a quick point of clarification from a confessed flashaholic....

That just doesn't sound right.

[ApexShootingTactics]

Allen,
Good info thanks for sharing. The heat issue I mentioned came directly from a flashlight clinic at Shot Show a few years back when there was a huge LED push.

The fins on the side of the stream lights are not for heat. They have flat edges to limit how far they will roll away when dropped. So if you are next to a vehicle, drop your light it won't or shouldn't roll too far under the vehicle.

[TSiWRX]

Allen,
Good info thanks for sharing. The heat issue I mentioned came directly from a flashlight clinic at Shot Show a few years back when there was a huge LED push.

Interesting.....

I'd like to meet the person that gave that clinic. That heat info. the presenter gave really goes contrary to all known science where it comes to LEDs, no matter the application.

Another cross-example that again helps to explain the heat production difference between LEDs and filament-burning incandescents is the case of photobiomodulation. In many rodent experiments - all approved via very rigorous regulatory bodies to insure the safety and comfort of the animals - the LED array (example: http://www.quantumdev.com/products/led/spectralife.html" onclick="window.open(this.href);return false;) is placed usually within an inch or two above the the live, non-anesthetized animals. This would never be allowed if not for the fact that the LEDs do not generate forward heat, such as a typical "heat lamp" - or even standard incandescent bulb - would generate.

Similar to the Audi headlamps, these units use a robust heat-sink behind the LED array, and further vent heat from the star via a CPU case fan.

Even as far back as 2000, we flashaholics (yes, pirateguy191, that's a very real term! ) well understood this difference and tailored custom high-powered LEDs - which was at that point a custom-build hobby - to these differences.

A quick experiment, if you've still got a few standard incandescent heads laying around for your Surefires, that you can play for yourself: I've currently got a Surefire E2D Defender to which I've re-installed a brand-new MN03 60 lumen incandescent lamp assembly, a Surefire Z2 that I've also re-installed a brand new P60, 65 lumen incandescent lamp assembly, as well as a C2 that is housing the aforementioned drop-in Malkoff M91A (750 OTF lumens at start up, 650 constant). I've now left them on for about an hour. The latter's body is now uncomfortable to hold, but at its lens - without any type of scalloping/crenalations to the bezel - it's at 97 degrees. The two incandescents are registering lens temperatures of close to 140 degrees.

I am both surprised and disappointed that someone from within that industry could have given out such incorrect information to a crowd at SHOT - especially to those like you in the audience, whose very life could depend on these lights!

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The fins on the side of the stream lights are not for heat. They have flat edges to limit how far they will roll away when dropped. So if you are next to a vehicle, drop your light it won't or shouldn't roll too far under the vehicle.

^ Ah! Good to know!

I could not see via the pictures if those rings were complete circles, or if they were machined flat in spots to prevent rolling.

[TSiWRX]

Correction -

My laboratory assistant would like to call attention to my error in the previous post. The lens temperature of the MN03 peaked at just 124 deg. F. at approx. 25 minutes into the test. Thereafter, it actually gradually declined.

[ApexShootingTactics]

Allen,
Back when LEDs were starting to take over there was a.... lack of a better term, public service announcement regarding LED failures. I searched all my emails looking for this thing but can't find it. You recall this or can you explain it? The PSA showed some discolored lenses and burnt LEDs.

Concerning the presentation at Shot Show, I did win a Surefire LED Defender for answering some trivia question. That light has the caution label concerning heat on the side of the bezel.

Not trying to argue just sharing info.

[TSiWRX]

^ No worries - not argumentative at all, and I hope you don't receive my reply as such, either.

Somewhere towards the beginning of when lamps were getting "turned up" in terms of output - this was even before LEDs really stepped onto the scene (we need to remember that consumer "tactical" high-output handheld LED lights did not really get underway until the 3xCR123 powered Surefire L6 stepped onto the scene in ~2004, with a 5W Luxeon star that produced 100 lumens for a regulated 1.5 hours, at a retail cost of nearly $300) - we started noting that the then-current generation of Lexan and other "plastic" lenses were melting. Even the incandescent Surefire P60 lamp - at 65 lumens output and absolutely tame by today's standards - was capable of this.

We've come a long way in the intervening years, of-course. Back in those days, we clamored for various glass lenses and even at one point had to choose between strength/durability (Pyrex) versus clarity ("UCL"). Today's polymer lenses offer more than sufficent clarity/transmission and tremendous durability. Back in the early- to mid-'00s, dropping a flashlight, even a high-priced one, can potentially result in a cracked lens. That's now - if not altogether uncommon - rather far less common.

"Burnt" LEDs would come from insufficient heat-sinking. As with the above real-world high-powered LED examples, a Google Image search for "LED heat sink" demonstrates this very nicely.

That heat warning on the bezel of the Defender isn't about forward heat, but rather, that the flashlight itself, in-entirety, gets hot. Since you have these lights at-hand, it's easy replicate my primitive experiment above. If you kept that light on long enough, you'll quickly feel that heat build up first at the bezel - where the heat-sink of the LED star is located. From there, that heat will conduct down the entire length of that aluminum body. If you have an infrared thermometer, it'll be very easy to take a temperature of the light at the lens versus at the bezel versus at the body. Compare this with the same three areas on even a very modestly powered incandescent, such as the P60 burner which I used as my "control" above.

That heat warning will become very apparent to you after you've kept that Defender on for about a half hour to an hour.

Will the lens on a high-powered LED light also climb in temperature? Yes, it definitely will (per my test above, room-temperature as 63 deg. F., peak lens temperature was 97 deg. F.), but it's not due to forward heat - not as an incandescent lamp would produce (which on the P60 I tested above reached 140 deg. F.). Rather, it's due to that heat that's conducted down the body of the light from its heat sink. When we hobbyists started to Frankenstein Surefire bodies with LED drop-ins, at one point, Surefire put out a very stern warning that end-users should not use their drop in LED P60L replacement lamp assembly in their polymer-bodied/bezel units - the reason, for as much as it was damage to the bezel, was also damage to the star itself as the polymer body/bezel could not sufficiently conduct the heat generated by the star. It's that heat - not forward heat as an incandescent bulb would produce - that was the problem.

There's still some marketing-speak that will mention bezel crenelations/scallops as a method for heat control. Elzetta was (maybe still do?) among those that at one point made this claim. If this is true and that important, then one has got to ask the logical question: why would they offer non-crenelated/scalloped options, particularly with extremely high-output variants? [Also, how would the crenelations/scallops help in controlling heat? Look at the physical architecture of the CREE household bulbs that I cited above (also here: http://www.treehugger.com/energy-effici ... eview.html" onclick="window.open(this.href);return false;) - there's a physical reason why they are able to do away with the heat sink in those "bulbs"...is that possible in a tubular flashlight?]

There's a reason why those early LED traffic-lamps couldn't melt the ice/snow that's built up in front of them. There's a reason why the Audi's headlamps utilize such a fancy heat-control setup.

The way an LED produces heat is physically different than the way an incandescent filament-burning lamp does, it's really as simple as that.

I really wish I could be there this Saturday night - we'd have some fun and burn through a few of my batteries (and even lamps), for-sure! Unfortunately as I mentioned before, the wifey is on-call.