US What a DIN rail is
A DIN rail is a standard metal rail, fixed to the back plate of a cabinet, that electrical and control equipment clips onto. It gives every part in the cabinet the same mounting interface, so components from different manufacturers sit side by side in neat rows.
DIN stands for Deutsches Institut für Normung, the German standards body where the rail began; its dimensions are now set internationally in EN 60715. Equipment has a clip on the back that hooks over the rail and snaps into place, so a whole cabinet can be fitted out, and later changed, without drilling new holes for each part.
The rail is usually zinc-plated or passivated steel, cut to length and screwed to the panel. Slotted versions save weight and give more fixing points. Aluminum and copper rails exist for special uses, such as light assemblies or earth bars.
DIN rail types and sizes
EN 60715 covers several rail profiles. The 35 mm top-hat rail is by far the most common, and when people say “DIN rail” without qualification they almost always mean it. The table lists the main profiles with their published dimensions.
| Rail profile | Size (width × depth) | Earlier standard | Typical use |
|---|---|---|---|
| Top-hat TS35 | 35 × 7.5 mm | EN 50022 | Most control cabinets: breakers, terminals, PLCs, power supplies |
| Top-hat TS35 deep | 35 × 15 mm | EN 50022 | Heavier equipment such as large power supplies and industrial PCs |
| Miniature TS15 | 15 × 5.5 mm | EN 50045 | Small, light parts such as compact terminals and relays |
| G-section | 32 mm asymmetric | EN 50035 | Older installations and heavier terminal blocks |
| C-section | Several C profiles | EN 50024 | Legacy panels; rarely specified for new work |
Check the depth as well as the width when you choose equipment. A deep or heavy device on a 7.5 mm rail can flex the rail, so larger power supplies and computers often call for the 15 mm deep version or extra fixing to the back plate.
What mounts on a DIN rail
Almost anything that lives in a control cabinet is now made in a DIN rail version. A typical industrial cabinet carries:
-
//
Protection. Miniature circuit breakers, residual current devices and surge protection.
-
//
Power. DIN rail power supplies that turn mains into 24 V DC for the control system, plus DC UPS modules.
-
//
Wiring. Terminal blocks, fuse terminals and earth terminals that tidy field wiring before it reaches the equipment.
-
//
Control. PLCs, remote I/O, relays, timers and motor starters.
-
//
Networking and computing. Industrial Ethernet switches, serial converters, IoT gateways and compact industrial PCs.
How DIN rail mounting works
Each device has a fixed hook at the top of its mounting clip and a spring latch at the bottom. Hook the top over the rail, push the bottom in until the latch clicks, and the device is held. To remove it, pull the latch down with a flat screwdriver and tilt the device off. End stops at each end of a row stop parts sliding along the rail.
Because parts slide along the rail, a cabinet can be rearranged without new holes, and a failed device can be swapped in minutes. Our DIN rail mounting guide explains how to fit a computer, including clip orientation, clearances for cooling and cable routing.
Planning a DIN rail layout
A well-planned rail layout makes a cabinet easier to wire, cool and maintain. A few habits help on most projects:
-
//
Leave spare rail. Many panel builders leave around a fifth of each rail free for later additions.
-
//
Group by function. Keep power, control and network equipment in their own rows, with wiring duct between them.
-
//
Separate power and signal. Route mains and motor cables away from Ethernet, serial and analog signal wiring to limit interference.
-
//
Allow for heat. Leave the clearance each device asks for above and below, especially around power supplies and computers.
DIN rail computers
A DIN rail computer sits in the same cabinet as the PLCs and power supplies it works with, so data collection, HMI back ends and edge analytics can run next to the machine instead of in a separate rack. Our DIN rail PCs are fanless, designed for the heat inside a closed cabinet and usually take a wide DC input so they can run from the cabinet’s 24 V supply.
For smaller jobs, such as reading Modbus or serial devices and passing the data to the cloud, our industrial IoT gateways do the same work in a narrower housing. Where a touch screen is needed on the cabinet door, our HMI and PLC FAQ explains how the operator panel talks to the controller.
Quick answers on DIN rails
DIN rails: common questions
What does DIN stand for in DIN rail?
Deutsches Institut für Normung. It is the German standards institute that first standardized the rail. The rail is now defined internationally in EN 60715.
What size is a standard DIN rail?
35 mm wide. The standard top-hat rail is 35 mm wide and either 7.5 mm or 15 mm deep. A 15 mm miniature rail is used for small parts.
Can you cut a DIN rail?
Yes. Rails are sold in long lengths and cut to fit with a hacksaw or rail cutter. Deburr the ends so they do not damage cable insulation.
Is a DIN rail earthed?
Often, but do not rely on it. Rails are commonly bonded to the cabinet earth, but protective earth should run through proper earth terminals unless the design says otherwise.
What is the difference between top-hat and G-section rail?
The profile. Top-hat rail is symmetrical and 35 mm wide. G-section is an older asymmetric profile, still found on some heavier terminal blocks.
We supply DIN rail PCs and gateways with the operating system, I/O and mounting kit fitted as standard, and test each system before it ships. Tell us the cabinet size, supply voltage and the equipment it needs to talk to, and we will specify a computer to match.