10 Parts of a Flashlight With Diagram: A Beginner’s Guide

Last Updated on May, 2024

Have you ever wondered what’s really in it when using an appliance? Usually, that sparks curiosity to know what really goes on inside it.

Luckily enough, this information read will cover the parts of a flashlight and some more interesting facts you’re not going to find anywhere else.

Let’s get into it!

Quick Summary

The first modern electrical flashlight was invented in 1899 by a Russian-American inventor named Conrad Hubert.

The parts of a flashlight include the bezel, light source, reflector, lens, housing, power source, main switch, and circuit.

A flashlight is made up of many different parts, each with a specific function. The most important part of a flashlight is the circuit, which directs the current from the power source to the light source.

A Brief History of the Flashlights

flashlights on the floor

The idea of portable light sources has been present since the era of Homo Erectus. However, a Russian-American inventor named Conrad Hubert invented the modern electrical flashlight in 1899. But why is it called a “flashlight”?’; it has an interesting origin.

Early flashlights required resting times since they couldn’t stay on for a long time, and their prolonged function made them ‘flash’ for a brief period, hence the American name, “Flashlight.”

After over 100 years ahead, Ann Makosinski is a Canadian inventor who invented the Hollow Flashlight, a flashlight that is powered by the heat of the human hand. Pretty cool, huh?

The Top Types of Flashlights You Should Own

Choosing a flashlight can be challenging simply because there are so many. But let me introduce you to some of the must-have flashlights. 

EDC Flashlight

The first one is the EDC flashlight (everyday-carry flashlight). These are pretty small in size and come in many types. The categorization is mainly based on the battery; AA, AAA, and rechargeable batteries are the three main types. 

EDC flashlights are pretty popular in the form of keychain lights. The lumen output can be as high as 500 in some cases, and novelty flashlights belong in this category.

Check out this post If this information is not enough & you want to know more about what is EDC flashlights.

edc flashlight

Tactical Flashlight

The second one is the tactical flashlight. Tactical flashlights are similar in size to those of EDC lights. However, tactical flashlights are easier to access and turn on by design. If you own a firearm, you NEED a tactical flashlight. The lumen output falls into the EDC range.

Both these types are much more durable than typical incandescent flashlights.

Diving Flashlights

The third type is diving flashlights, which are pretty much self-explanatory. While you might not be an everyday diver, owning a light that works underwater is handier than you’d expect.

So, you’d find these a tad more expensive than the regular ones.

Ideally, the lumen output should be somewhere between 2000-3000 in this type of flashlight.

diving man holding flashlight

Heavy-Duty Flashlights

Heavy-duty flashlights are the bigger, stronger, and heavier ones. You can expect lumen output levels of even 90,000. It’s borderline impossible to find rechargeable ones of this type, and most are waterproof. Having one as a long-term household investment is a great idea.

LED Flashlights

The next type is the LED flashlight. Everything else is pretty much the same as typical flashlights except for two features; the fact that they do not get heated up and the bluish-white light.

Headlamp Flashlights

A headlamp flashlight is a blessing when you’re working and you can’t hold a flashlight by hand.

Although the recommended lumen output is 100-400, the market has products emitting 10,000 lumens.

Now that you know all the types, let’s move to the inside of a flashlight.

flashlight on a man's head

10 Parts of a Flashlight

Parts Of A Flashlight

1. Bezel

flashlight Bezel

Lights with poorly designed bezels are ALWAYS going to be cheaper and, of course, less effective. The bezel is the outermost ring of the head of a flashlight, and it has two primary purposes.

The first one is to protect the lens since the material extends past the lens. The second one is to help you see whether the battery is being wasted when the flashlight stays face-down.

2. Light Source

types of lighting

It’s pretty much self-explanatory. 

The light source emits the flashlight’s light, which can be one light or more, and it could be either tungsten or LED.

The source of the light decides the lumen count. In addition, most branded flashlights will also specify the brand of the light source.

If it’s an LED light, you’ll find a bunch of numbers describing them. These have a meaning, and knowing them helps you buy cost-effective products. The three parts of an LED number are the model number, the version, and the BIN number, following a space.

Let’s look at an example.

XP is the model number in an XP-G2 R5, which makes G2 the version. If it was XP-G, then that’s the earlier version of the flashlight. So, what’s R5?

It’s the BIN number assigned by the LED manufacturer—usually, the further into the alphabet, the higher the number, the brighter the light.

3. Light Beam

beam characteristics

People don’t talk enough about the tint of the light beam. But why is it important? It’s since the color of the light depends on the setting the flashlight is used on. For example, the traditional yellowish light is ideal for outdoor applications.

The white LED light is recommended for the indoor setting since the beam can wash out colors. The neutral white is an advanced version of white light, and it’s ideal for underground and underwater illumination purposes.

The hot spot, as you can see, is the center of the light beam whereas the spill is the relatively dimmer part surrounding the hot spot.

It would be best if you also looked at the throw and the flood of the light beam. The throw is how far the light beam travels, and the flood is how much the light diffuses. This usually takes place in close distances.

So, be sure to look out for this terminology when you’re browsing flashlights.

4. Reflector

A light source emits rays in spherical directions, which means all around. So, the flashlight will be useless unless the direction of the light rays isn’t regulated. That’s where the reflector comes in.

The reflector bounces off the light rays emitted from the source, typically in parallel rays to the lens. This can only be achieved when the reflector is parabolic, not convex or concave.

You might want to reconsider if your flashlight is categorized as having a “mule” of a reflector.

Because generally, the flashlight doesn’t have a reflector, making the light less focused and diffusing into a vast area. If that sounds like your purpose, go for it!

flashlight Reflector

5. Lens

flashlight lenses

The purpose of the lens is to emit light rays to satisfy the user’s needs. Usually, the lens is concave and distributes the heavily concentrated light rays to the lens. This process is termed the ‘spill’ in the industry.

Think of this process as a dilution; the final light beam won’t have enough luminance if the light isn’t strong enough.

Simultaneously, flashlight lenses are expensive and can malfunction heavily with a tiny crack. So, be sure to safeguard the lens at all times.

6. Housing

The housing is what covers the entire flashlight, the outfit of the flashlight. You wouldn’t wear your work clothes to dive, would you?

The same theory applies here, which is why diving flashlights are much more expensive and have unique housing materials.

Patterns are as crucial as the material from which they are made.

Diving flashlights tend to have more irregular patterns to ensure grip, while EDC flashlights focus mainly on the convenience of usability.

Knurling is the technical term for cutting lines or grooves into the housing of the flashlight. The more aggressive the knurling is, the harder the grip will be.

flashlight housing on floor

The material of the housing decides whether your flashlight is shockproof as well. Apart from shock, there are many other types of damage the housing can defend against, and being aware of these at the time of purchase is what you should do.

These are the main types of materials that flashlights are made of.

  • Stainless Steel: Highest resistance to wear.
  • Aluminum: softer than stainless steel, its conductivity works well with the heat from LEDs. Most Aluminum made flashlights are labeled as hard-anodized to ensure their resistance to corrosion.
  • Titanium: Most high-quality flashlights will likely have titanium housings because they are better than stainless steel.
  • Brass/Copper: Copper, brass, or any other exotic metal is used to manufacture housings, mainly for aesthetic purposes. Although durability and other factors might not be strong, the people who buy these don’t mind that since they know the downsides of the metal.
  • Battery Compartment + Batteries (Power Source)

Unless otherwise, 99% of the flashlights on the market are powered by batteries. These batteries are mainly categorized as AA or AAA batteries. The batteries go in the battery compartments, and you MUST check the condition of the compartment from time to time. 

Forgetting that could result in salt layers in the compartment and acidified batteries, especially in the diving flashlights.

7. Pocket Clip

You wouldn’t find the pocket clip in a diving flashlight or a heavy-duty flashlight, but a similar part serves a similar purpose.

The pocket clip helps you ‘wear’ the flashlight quickly, like a pen. All tactical and EDC flashlights have pocket clips.

However, it’s mindful to ensure that they do not need extra effort to stay worn since the end of the clip doesn’t tightly touch the flashlight’s body.

If the pocket clip is absent, there must be an alternative. For example, it could be a holster. If not for a holster, it also could be lanyard holes for smaller flashlights.

These holes allow you to wear the flashlight on a keychain or necklace.

flashlight Pocket Clip

8. Tail Cap

Tail Cap of flashlight

This part plays a significant role in a flashlight. If it doesn’t work in yours, it basically means that yours isn’t up to the standards. The tail cap’s function is to act as a secondary switch. But the nature of this switch directly affects the price of the flashlight.

The nature of the switch means the mechanism of turning the flashlight on. Twisting is the first mechanism; it takes a considerable amount of energy and is annoying.

A side switch starts from the tail cap but acts as a rather discreet switch that pushes the flashlight forward. 

A clicking mechanism is what you should look for. Usually, this sort of tail cap has two levels; when you press it once, the light turns on, but it turns off as you take your finger off. Pressing the switch twice turns the light on.

9. Main Switch

main switch of flashlight

Yeah, yeah, I know; the switch turns the flashlight on. But sometimes there’s more to it. For example, there could be off, dim, and fully turned-on options. Having that sort of brightness setting is truly useful, just as much as a well-functioning tail cap.

10. The Circuit

The Circuit of flashlight

If not for the circuit, none of these parts would be helpful. The circuit is what absorbs the current generated from the power source and conveys it to the light source. 

We don’t need to get overly technical here, but you should know that it involves interconnected metal strips and electrons running counterclockwise.

Here’s how to make a LED flashlight circuit.

How to Rebuild a Flashlight From Dismantled Parts?

flashlight parts on the floor

When dismantled, these are the circuit parts that you’d find in a flashlight.

  1. Spring
  2. Copper wire
  3. Plastic button
  4. Main tube
  5. Conducting washer 
  6. Parabolic reflector
  7. Clear lens
  8. Lens case
  9. Outer parts of the flashlight

So, how do you put one together?

You can start by attaching the plastic button to the copper wire. The button can then be attached to the plastic tube such that it projects through the hole in the plastic container. 

The bulb should now be inserted into the conducting washer, passing through the washer’s center. Make sure the washer’s hollow interior and the glass portion of the bulb face the same way. 

The hollow part of the washer should snap into place with the parabolic reflector when you attach the bulb and washer. Put the reflector on top of the container such that the metal bulb base tip protrudes from the reflector. Just place the reflector on the container.

Put the lens shell onto the plastic container, place the transparent plastic lens on top of the parabolic reflector, and you’re done!

Is Relying on Your Phone Torch Ideal?

a human holding a phone

One of the most common questions you’d ask yourself before buying a flashlight is whether you ACTUALLY need one. Why? Because your phone has a built-in torch.

However, relying on your smartphone’s torch is not ideal. There are many reasons that flashlight manufacturers point out. And they do make a lot of sense.

  • Phones run out of power faster than you think they will.
  • The lumen output of a typical phone torch is around 40-50 lumens. 
  • You won’t be able to pull out a typical phone in the rain.
  • Using the torch of a smartphone in extremely confined places isn’t always successful.
  • It doesn’t cost that much to buy a flashlight in the 2020s.

Now that we’re on to cost, let’s look at the 2022 market.

What’s the Current Market Like?

Amazon is the BEST place to get the benchmark price idea quite quickly. 

The most expensive AA flashlight which is XZJJZ Mini Flashlight Zoomable Q5 is priced at $159 since it has a whopping lumen count of 2000. The cheapest one is an Eveready LED flashlight priced at less than $5. Although the lumen count isn’t mentioned, you can see it’s a price-worthy product when you read customer reviews.

A reliable AAA flashlight would generally exceed the $10 mark. But if it reaches the $20 mark, you’re guaranteed to have a 200+ lumen count.

It’s safe to say AAA products generally range between $10-$50, although the better ones exceed the $200 mark with 10,000+ lumen output.

Diving flashlights typically start around the $20 mark and can even exceed the $1000 mark; this DIVEPRO G18 Plus, with 18,000-lumen output, is an excellent example.

The average price of headlamp flashlights is around $15-20, and this is for a very decent lumen output of 1000-1200; here’s an example.

flashlights on the stone

Although you’d expect the price of heavy-duty headlights to be much higher, it’s not so; it’s a matter of filtering out the correct product; For example, this product is $330, and this rechargeable LED heavy-duty flashlight has 1000 lumens.

The bottom line is that you should do your research when buying a flashlight since only YOU’RE aware of your needs. But as far as the research goes, this is the price range.

In Conclusion

Understanding the parts of a flashlight is the stepping stone of evaluating the worth of a purchase. No matter what’s in Amazon reviews, analyzing the specs of a flashlight on your own is more reliable. If you read to the very end to this reading, congratulations, you know EVERYTHING one must know about the anatomy of a flashlight.


Lumen is a unit of measurement for the amount of light emitted by a source, equal to 12.57 candela. The higher the lumen amount, the brighter the light.

No, a flashlight’s flood and throw are not usually mentioned in the product; one must do the calculation themselves.

The typical lifespan of an average flashlight is between 5,000 and 10,000 hours.

Was this article helpful?

Photo of author
Dillon Morrison
I have been involved in the flashlight community since 2007. My brother has a flashlight shop from where I have tested and reviewed more than 600+ different types of flashlights. You can find more about me here.

Leave a Comment