5mm LED Specifications Explained: Voltage, Current, Viewing Angle and Selection Tips
1. What Does a 5mm LED Look Like
The 5mm LED, generally called F5 in the industry, is a through-hole LED with a 5mm-diameter epoxy body — the classic indicator lamp found everywhere: home appliances, chargers, power strips and industrial control panels.
A standard F5 has a simple structure: a round epoxy body containing the lead frame, chip and gold wire, with two leads coming out of the bottom — the long lead is the anode, the short one the cathode. The body is 5mm in diameter, total lamp height about 8.6mm, and standard lead length around 25mm; leads can be cut to length or formed with a 90° bend for horizontal board mounting.
Why has the F5 stayed popular for decades? First, its structure is simple and reliable — the epoxy body fully encloses the chip and gold wire, resisting vibration and moisture. Second, it is highly versatile, working from 3V gadgets to 220V power strips (with a current-limiting resistor). Third, the supply chain is mature with huge stable volume — any electronics factory's purchasing list contains a string of F5 part numbers.
2. Core Electrical Parameters
The rated operating current of a 5mm LED is 20mA, generally not exceeding 30mA maximum. Forward voltage mainly depends on the emitting color, because different colors use different chip materials:
| Emitting Color | Forward Voltage (Typical) | Notes |
|---|---|---|
| Red, yellow, yellow-green | 1.8-2.2V | Traditional chip solution, mature technology |
| Orange, amber | 2.0-2.4V | Voltage between red/yellow and blue/white |
| Blue, pure green, white | 2.8-3.4V | InGaN chips, one step higher in voltage |
Two other frequently asked parameters: first, viewing angle — round-head focused types are usually 15°-45°, while diffused (milky) types can exceed 60° for wide-area diffusion; second, single-unit power — about 0.06W, very little heat, which is why it can stay lit for years as a power indicator.
In practice, keep two more things in mind: even for the same color, chips from different makers vary by 0.1-0.2V, so measure actual voltage before calculating the current-limiting resistor for volume orders; also, LEDs ship in bins — request the same brightness bin for one order, otherwise a row of indicators will light up unevenly and fail visual inspection.
3. How to Choose Between 5mm and 3mm
F3 and F5 have almost identical electrical parameters; the difference is mainly the emitting area and mounting hole. At the same 20mA drive, the 5mm body and emitting area are larger, more eye-catching overall, with a longer indication distance; 3mm is smaller, suiting small panels with densely packed lamp rows.
Follow the panel hole when selecting: a φ3 hole takes an F3, a φ5 hole takes an F5 — do not mix them up; a lamp rattles in an oversized hole and will not fit an undersized one. If unsure about dimensions, manufacturers usually publish drawings on their websites — the F5 through-hole LED (5mm indicator) product page, for example, lists its outline dimensions.
Another case: space is available but you want extra margin. The price gap between 3mm and 5mm is small; the 5mm has a thicker lead frame and slightly better heat dissipation, giving steadier lifetime under continuous operation. Conversely, for matrix-style dense indicator panels, 3mm or even the smaller 2mm nipple-head is more suitable.
4. Typical Applications and Customizable Options
The most common job for a 5mm LED is the power indicator: power strips, chargers, water dispensers, water heaters, induction cooker panels, plus run/fault status lights on industrial equipment — toys and decorative lighting use plenty too.
An easily overlooked high-volume application is advertising signage and channel letters. Many early exposed LED string lights on signboards were built from F5 lamps; waterproof versions hang outdoors for years, demanding UV resistance from the epoxy and rust resistance from the lead frame — which is why signage customers are especially sensitive to LED quality.
In practice, far more items are customizable than most people think: emitting color (red, green, blue, yellow, white, bi-color), brightness, viewing angle, lens effect (clear, diffused, white-body red, white-body green), lead length, 90° bent-lead forming, and even built-in current-limiting resistors for direct 12V or 24V drive versions. Before ordering, write down the five items — "color + voltage + brightness + viewing angle + lead form" — and you basically cannot go wrong. For more models, browse the Through-Hole LED Series category.
About Hongcheng Optoelectronics
Hongcheng Optoelectronics (Dongguan Hongcheng Optoelectronics Co., Ltd.) has 20+ years of LED packaging experience. Products use Grade-A chips and 99.9% pure gold wire bonding, are RoHS certified, and support customization, samples and volume quotes. Tel/WeChat: 139 2571 4318, Email: sales@led-hc.com.
