DIN Rail Dimension

In the world of industrial control panels and electrical enclosures, a simple metal strip provides the foundation for nearly every component inside: the DIN rail. This standardized mounting system allows for the neat, efficient, and secure installation of everything from terminal blocks to circuit breakers. A thorough understanding of DIN rail dimension is fundamental for engineers, panel builders, and technicians to ensure compatibility and create well-organized, maintainable systems.

This guide provides a detailed technical breakdown of the most common DIN rail dimension and specifications. Xingrail will explore the various types, from the ubiquitous Top Hat to the specialized G-rail, complete with dimensional tables and material standards. Adhering to these specifications is not just about making parts fit; it’s about building safe, reliable, and standardized electrical assemblies.

DIN Rail Dimension

DIN rails are more than just metal strips; they are precision-engineered components defined by international standards, primarily IEC/EN 60715. The name “DIN” comes from the “Deutsches Institut für Normung” (German Institute for Standardization), which pioneered these standards. The dimensions of a DIN rail—specifically its width, height, and profile shape—determine which components can be mounted on it. There are several key types, each with its own set of standard dimensions and applications.

35mm “Top Hat” Rail (TS35) – The Industry Standard

The 35mm Top Hat rail is the most common and versatile type of DIN rail used today. Its symmetrical, hat-shaped cross-section provides a secure and stable mounting platform for a vast array of electrical and electronic components. It is specified in two main height profiles: 7.5mm and 15mm.

DIN Rail Dimensions TS35 x 7.5mm

This is the most prevalent profile, offering a low-profile mounting solution suitable for most standard components like terminal blocks, relays, and power supplies.

DIN Rail Dimensions TS35 x 15mm

The “deep” or “high” Top Hat rail provides greater clearance from the mounting panel. This additional height is useful for accommodating larger components, such as heavy-duty contactors or certain power supplies, and allows for more space behind the rail for wiring.

DIN Rail Dimension 15mm Miniature Rail (TS15)

The TS15, or “mini-rail,” is a smaller version of the Top Hat rail designed for compact applications where space is at a premium. It is ideal for mounting smaller components like miniature terminal blocks, interface modules, and compact relays. Its dimensions are proportionally smaller, making it unsuitable for standard 35mm components.

DIN Rail Dimension Specialized and Asymmetrical

While the Top Hat rail dominates modern designs, other asymmetrical profiles were historically significant and are still used in certain applications. These profiles, known as C-rails and G-rails, offer unique mounting characteristics.

32mm G-Rail (TS32)

The G-rail, or TS32, is an asymmetrical rail recognizable by its “G” shaped profile. It features one deep channel and one shallow channel. This design provides two key benefits: it offers enhanced support for heavier or deeper components, and its asymmetry prevents components from being installed upside down. While less common now, it is still specified for certain heavy-duty applications.

C-Rail Profiles

C-rails feature flanges that point inward, creating a C-shaped cross-section. They come in several widths (e.g., C20, C30, C40, C50) and were used for mounting specific types of switchgear and older terminal block systems. They provide excellent stability but are less versatile than Top Hat rails and are largely considered a legacy standard.

DIN Rail Dimension Material Specifications and Finishes

The performance and durability of a DIN rail are not only dependent on its dimensions but also on the material it is made from and its surface finish.

• Steel: The most common material for DIN rails is cold-rolled steel. It offers an excellent balance of strength, rigidity, and cost-effectiveness.
• Aluminum: Aluminum rails are lightweight and naturally corrosion-resistant. They are a good choice for applications where weight is a concern or in environments with moderate humidity. However, they are not as strong as steel and may not be suitable for supporting very heavy components.
• Copper: Copper DIN rails are used exclusively as grounding busbars. They are never used for mechanical mounting but provide a convenient, centralized grounding point for an entire panel when used with grounding terminal blocks.

Surface Finishes

The surface finish protects the rail from corrosion and ensures good electrical conductivity where needed.

• Zinc Plating with Chromate Passivation: This is the most common finish for steel DIN rails. The zinc layer provides sacrificial corrosion protection, while the clear or yellow chromate passivation layer seals the zinc, significantly extending its life. Modern rails use trivalent chromate (Cr3) to comply with environmental regulations like RoHS, replacing the older hexavalent chromate (Cr6).
• Unplated (for Copper): Copper grounding rails are typically left unplated to ensure the best possible electrical connection.

Frequently Asked Questions (FAQs)

What is the most common type of DIN rail?
The 35mm x 7.5mm “Top Hat” rail (TS35) is the most widely used standard across all industries. It supports the broadest range of components from different manufacturers, making it the most versatile choice for control panel design.

Can a DIN rail be used as a ground bar?
A standard zinc-plated steel DIN rail can function as a chassis or protective earth (PE) ground, provided it is properly bonded to the enclosure’s ground point. Special grounding terminal blocks are designed to bite into the rail, creating a reliable electrical connection.

What is the difference between a 7.5mm and 15mm high Top Hat rail?
The 15mm high rail provides more clearance between the components and the back panel, which is useful for managing wiring or mounting deeper devices. It also offers slightly more rigidity for supporting heavier loads. The 7.5mm rail is a standard, low-profile option.

Are DIN rail dimensions imperial or metric?
All official DIN rail standards (IEC/EN 60715) are specified in metric units (millimeters). While they are used globally, including in the US, the core dimensions are universally metric, ensuring worldwide component compatibility.

What are perforated DIN rails for?
Perforated rails have pre-punched oblong slots along their length, typically spaced 25mm apart. These slots simplify mounting the rail to a back panel, as they provide flexibility in fastener placement and eliminate the need for drilling. Non-perforated rails offer maximum strength and are drilled on-site.