The question of what thread is on the fitting of a car camera often arises among car owners who decide to install a video surveillance system or replace a standard device. Many drivers buy universal recorders or rear view cameras without thinking that the fastening elements may differ significantly. A discrepancy between the diameter or thread pitch makes it impossible to install the equipment without additional adapters or mechanical modifications.
The modern auto electronics market offers many form factors, from miniature “eyes” to massive blocks. fitting - this is the protruding part of the body on which a thread is cut for a nut that presses the camera to the body or bracket. It is very easy to make a mistake in your choice, since visually similar models can have completely different technical characteristics. In this article we will analyze in detail the basic standards and help you avoid mistakes when purchasing.
Understanding thread sizes is necessary not only for initial installation, but also for subsequent maintenance. If you plan to replace the camera with a more modern model, the old hole may not fit the new one fastener. Knowing the parameters in advance, you can order the correct kit or adapter, saving time and nerves. Let's look at which sizes are most common and how to correctly identify them.
Basic standards of metric threads in auto electronics
In the vast majority of cases, car camera manufacturers use metric threads. This is a standard that ensures compatibility with common tools. The most common size is thread M5. It is considered the gold standard for compact rear view cameras and interior recorders. The diameter of such a screw is 5 millimeters, and the thread pitch is usually 0.8 mm.
The second most popular standard is thread M6. It is more often used in larger devices, such as cameras with IR illumination or models integrated into the license plate frame. The larger diameter provides a more secure hold and vibration resistance, which is critical for equipment mounted outside the vehicle. Sometimes you can find larger sizes, but they already belong to specialized equipment.
It is important to note that in addition to diameter, there is the concept of thread pitch. In the automotive sector, for sizes M5 and M6 it is almost always used standard pitch. However, when using adapters from inch standards (which is rare, but does happen in tuning), you may encounter incompatibility. Therefore, always check the contents before drilling holes in the body.
When purchasing a camera, pay attention to the presence of adapter nuts of different sizes in the kit - this often allows you to avoid searching for adapters.
Specifics of M12 thread and other large formats
The carving deserves special attention M12. This size is typical for dome surveillance cameras, which are sometimes installed on commercial vehicles, buses or special equipment. Such devices have significantly greater weight and dimensions, and therefore require reinforced fastening. If you are the owner of a truck or minibus, the likelihood of encountering this particular standard is very high.
Sometimes in the descriptions you can find a mention of carving M8. This is an intermediate option that is less common, but is still present in the lineup of some Asian electronics manufacturers. The main difference between such cameras is their focus on specific niches, for example, installation in rear-view mirrors with a built-in display, where a balance between durability and compactness is required.
⚠️ Attention: Do not forcefully tighten the nut if it cannot be tightened by hand. You may strip the threads on the camera's plastic body or damage the metal fitting, which will result in the need to replace the entire device.
When working with large form factors, it is important to consider the length of the threaded part. The fitting can be short, designed for thin metal, or long, designed for installation through a thick layer of thermal insulation or decorative overlays. Thread length directly affects the choice of nuts and washers.
What to do if the thread length is not enough?
If the standard protrusion is not enough to pass through a thick layer of material, you can use special extension sleeves or select a longer screw of the same diameter and pitch, after making sure that its head will not interfere with the installation of the lens.
Inch standards and adapters for DVRs
Although the metric system dominates, in the world of automotive tuning, especially when using American or Japanese-made equipment, inch standards may be found. The most common size here is 1/4 inch. It is often used in action cameras that are mounted on suction cups or brackets, as well as in some models of recorders.
To pair metric cameras and inch mounts (or vice versa), there are special adapters. They are small metal or plastic bushings with different threads on the inside and outside. The use of such elements allows for greater compatibility of equipment, but adds an extra connection point that can become loose due to vibration.
- 🔧 M5 to 1/4" adapter allows you to attach a compact camera to a standard photo tripod.
- 🔧 An M6 to M5 adapter is needed if the kit includes only thin nuts, and the camera has a wide fitting.
- 🔧 Extension sleeves help mount the camera through thick decorative interior panels.
When choosing an adapter, the quality of the metal is critical. Cheap alloys can warp, causing the camera to skew and reduce visibility. Brass or nickel-plated steel adapters last longer and withstand temperature changes better.
The use of high-quality metal adapters prevents camera rattling and image loss on the go.
How to accurately determine thread size without a caliper
If you don’t have precise measuring instruments at hand, you can determine what thread is on the fitting using the selection method. Take a standard M5 or M6 nut (they are in any motorist's kit) and try to carefully screw them onto the fitting. If the nut screws on easily and without play, you have found the correct size. This is the easiest and most affordable way diagnostics.
Another method is visual comparison with a known standard. For example, an M5 thread approximately corresponds to the diameter of a standard screw used to secure hard drives in computers or some car interior elements. The M6 thread is already noticeably thicker and comparable to the bolts for fastening suspension elements or brackets, although they are smaller.
For a more accurate determination, you can use a thread gauge if you have one in your arsenal of auto tools. This tool allows you to measure thread pitch, which is especially useful when working with non-standard or exotic camera models. However, for the mass segment of auto electronics this is unnecessary.
☑️ Camera compatibility check
Size Compatibility Comparison Chart
For ease of data systematization, we present the main parameters in table form. This will help you quickly navigate the variety of sizes and understand which equipment is suitable for your case. Please note the typical application of each size.
| Thread size | Diameter (mm) | Typical Application | Compatibility |
|---|---|---|---|
| M5 | 5.0 | Mini cameras, recorders | High |
| M6 | 6.0 | Cameras in the number frame | Average |
| M8 | 8.0 | Specialized systems | Low |
| M12 | 12.0 | Dome cameras, trucks | Special technology |
| 1/4" | 6.35 | Action cameras, tripods | Universal |
As can be seen from the table, the range of sizes is quite large. Trying to install a camera with an M12 thread into a hole intended for an M5 is physically impossible. Conversely, a small camera will not stay in a large hole without the use of adapter sleeves, which are not always included.
The nuances of installing and mounting cameras of different types
When installing the camera, it is important to consider not only the diameter of the thread, but also the method of fixation. Some models require the use locknuts, which presses the body tightly to the surface. Others have a spring mechanism or are secured with clips, where the thread plays a secondary role. Incorrect tightening can cause the camera to “walk” when moving.
Particular attention should be paid to tightness. If the camera is installed externally, the thread exit from the housing should be protected with a rubber gasket. Manufacturers often skimp on this element, and moisture gets inside through microscopic gaps in the threads. Use extra sealant or silicone grease during installation.
- 🚗 Always use a washer between the nut and the body to distribute pressure.
- 🚗 Do not overtighten the plastic case - it may crack.
- 🚗 Check the viewing angle after the nut is finally fixed.
Vibration is the main enemy of threaded connections in a car. Over time, the nut may unscrew spontaneously. To avoid this, it is recommended to use plastic ring nuts or apply a thread locker (such as Loctite) to the threads, but only if you do not plan to remove the camera frequently.
⚠️ Attention: When using thread locker, make sure that the chemical composition does not get on the lens or plastic interior parts, as some aggressive components can cause clouding of the optics.
Frequently asked questions (FAQ)
Is it possible to drill a hole for a larger camera?
This is technically possible, but not recommended unless necessary. Drilling the body requires anti-corrosion treatment of the edges of the hole. It is better to find a camera with a suitable standard size or use an adapter so as not to violate the integrity of the factory holes and not create pockets of corrosion.
Where can I get a nut if the standard one is lost?
Standard M5 and M6 nuts are sold at any auto parts or hardware store. If the thread is non-standard (for example, inch or a specific pitch), you will have to look for the nut in stores of radio components, photographic equipment, or order it from Chinese electronics suppliers.
Does thread length affect image quality?
The thread length itself does not affect the picture, but it does affect the camera angle. If the thread is too short, the camera may “bite” prematurely and you will not be able to set the correct horizon. In such cases, spacers or longer screws are used.
Do I need to lubricate the threads before installation?
For external cameras, it is advisable to lubricate the threads with lithium grease or graphite to prevent metal sticking and corrosion. This will make it easier to dismantle in the future. For indoor cameras this is not a requirement.
What to do if the thread on the camera is plastic?
Plastic threads are very fragile. Tighten the nut only with your fingers or lightly holding it with a wrench, without force. If the plastic fitting is torn, you can try to restore it with epoxy glue, but it will be safer to make a metal insert or replace the housing.