Industrial rectangular connectors are multi-pin connector systems built around a rectangular hood, housing, insert and locking structure. They are used when a machine panel needs high contact density, modular power/signal/data wiring, fast maintenance and a rugged cable-to-panel interface. In heavy duty connector systems, the rectangular form factor defines the housing architecture; current rating, IP sealing and termination method still need to be confirmed separately from the datasheet.
Choosing between a Han-style heavy-duty connector, a MIL-spec Micro-D, or a DIN 41612 backplane — and not sure which rectangular type fits? Because the rectangular form factor packs higher contact density and modularity than circular connectors, it dominates automation, defense, and transportation electrical systems. This guide covers the five main rectangular types, their specs and compliance standards, the four connection topologies, the five termination methods, and a step-by-step selection framework.
What Is an Industrial Rectangular Connector?
An industrial rectangular connector is a connector assembly that uses a rectangular housing to hold one or more inserts. The structure allows multiple circuits — power, signal, data or pneumatic channels — to pass through one panel opening. In factory automation and machine-building, this format is often called a heavy duty connector or Han-style connector.
The rectangular format should not be confused with the full electrical specification. The housing shape tells how the connector mounts, locks and organizes inserts; the actual current rating, voltage rating, IP rating, conductor range and termination method must still be checked from the specific product datasheet. For overall HDC selection, use the heavy duty connector selection guide.
IEC 61984 connector safety requirements
Industrial Rectangular Connector Anatomy
The value of an industrial rectangular connector comes from how its mechanical parts work together. A correct specification normally includes the hood, housing, insert, locking mechanism and cable entry system.
| Part | Function | Selection Risk | Related Guide |
|---|---|---|---|
| Hood | Cable-side outer shell that protects the insert and guides the cable entry | Wrong entry direction can create cable bending stress | This guide |
| Housing / base | Panel-side shell mounted to a cabinet, machine frame or junction box | Wrong mounting style can block panel installation | This guide |
| Insert | Holds power, signal, data or pneumatic contacts | Wrong insert layout causes pin-count or rating mismatch | This guide |
| Gasket and locking lever | Compresses the sealing interface when the connector is closed | Incorrect compression may reduce IP protection | Waterproof HDC guide |
| Cable entry / gland | Routes and seals the cable entering the hood | Wrong gland size causes sealing or strain-relief failure | Waterproof cable gland |
Han-Style Frame Sizes and Housing Logic
Han-style industrial rectangular connectors are selected as a matched mechanical system. The frame size determines how much insert space is available; the hood and base determine how the cable enters and how the connector mounts to the panel. A complete configuration usually combines these decisions:
| Configuration Item | What It Decides | Typical Question |
|---|---|---|
| Frame size | Available insert space and housing footprint | How many contacts or modules must fit? |
| Hood type | Cable-side protection and cable entry direction | Should the cable enter from the top, side or angled direction? |
| Base / housing type | Panel mounting and machine interface | Is the connector mounted on a cabinet, box or machine wall? |
| Insert type | Power, signal, data or hybrid contact layout | Is the connector carrying one circuit type or mixed media? |
| Locking style | Mating security and service access | Does the site need lever locking, screw locking or another system? |
For high-current power connectors that go beyond ordinary insert selection, use the heavy duty power connector guide.
Han frame size quick-reference: poles, current, and Verchil HE equivalents
A Han B-series frame is named by the number of Han E power contacts it holds. A Han 16B frame carries 16 contacts plus a dedicated protective earth; a Han 48B carries 48. As of 2026, a standard Han E insert is rated 16 A at 500 V per contact, per HARTING Han E datasheet figures published through distributors such as TME and RS. The table below maps each B-series frame to its contact count and the matching Verchil HE part, so you can size a housing straight from the pole count you need.
| Frame size | Han E contacts (+PE) | Per-contact rating | Verchil HE equivalent | Where it fits |
|---|---|---|---|---|
| Han 6B | 6 + PE | 16 A / 500 V | H6B | Small power-plus-control drops on a single module |
| Han 10B | 10 + PE | 16 A / 500 V | H10B | Compact machine modules and junction interfaces |
| Han 16B | 16 + PE | 16 A / 500 V | H16B | Mixed I/O and power on mid-size cells |
| Han 24B | 24 + PE | 16 A / 500 V | H24B | Dense control-cabinet feedthroughs |
| Han 32B | 32 + PE | 16 A / 500 V | H32B | High pin counts where one disconnect must do the whole job |
| Han 48B | 48 + PE | 16 A / 500 V | H48B | Maximum contact density in a single frame |
See the full Harting/ILME cross-reference matrix
Frame size sets how many contacts fit. The insert series sets what each contact can carry. Swap the Han E insert for a higher-current or higher-density variant when the load asks for it.
| Insert series | Per-contact rating | Profile | Pick it when |
|---|---|---|---|
| Han E | 16 A / 500 V | Power-and-control workhorse | Most cabinet-to-machine connections |
| Han D | 10 A / 250 V | Higher signal density | Control- and signal-heavy I/O |
| Han DD | 10 A / 250 V | Very high contact density | You need the most circuits in one frame |
| Han C | 40 A / 830 V | High current | Drives, heaters, and power feeds |
| Han HC Modular | 100 A+ per contact | Single high-current modules | BESS, busbar, and high-power links (see the heavy duty power connectors guide) |
Verchil’s HE series spans H6B to H48B at 16 A per contact, dimensioned to the Han B standard so it mounts in existing cutouts. The HDC-HE series page lists shell dimensions and insert layouts.
Hood orientation and cable entry
The housing and hood you build around an insert decide how the cable leaves the connector and how the assembly bolts to the panel. Pick the wrong geometry and you force a tight cable bend, or a hood that fouls the next machine over. Four choices cover most builds.
| Choice | Options | Decide by |
|---|---|---|
| Cable entry | Top entry vs side entry | Space above the panel vs beside it; side entry keeps a low overhead profile |
| Hood angle | Straight vs angled (90°) | Whether the cable runs parallel to the panel or drops away from it |
| Mounting | Bulkhead base (through a cutout) vs surface-mount housing | Whether the connector passes through the panel or sits on its face |
| Locking | Single lever vs double lever | Frame size and vibration — larger B-frames on high-vibration lines hold better with twin levers |
One detail trips up new builds: the cable gland thread on the hood has to match the cable. Size the gland (for example M20, M25, or M32) to the cable’s outer diameter so the seal and strain relief actually grip. The heavy duty waterproof connectors guide walks through gland sealing where an IP rating is on the line.
Rectangular Connector vs. Circular Connector : How to Choose?
A basic problem faced by engineers is: ‘Under what circumstances should rectangular connectors be used instead of circular connectors?’
The answer depends on the form factor, modularity, and application environment:
| Feature | Rectangular Connectors | Circular Connectors |
|---|---|---|
| Contact Density | Higher per unit area | Lower per unit area |
| Modularity | Highly configurable | Limited insert options |
| PCB Integration | Direct mount (right-angle/straight) | Complex, usually pigtail |
| Panel Space Efficiency | Excellent — tiles well | Moderate — wastes space |
| Blind Mating | Requires keying guides | Natural self-alignment |
| IP Rating Availability | IP20 through IP68 | IP67/IP68 common |
| Typical Application | Automation, panel mount, PCB | Aerospace, marine, field wiring |
Conclusion: Because rectangular connectors tile efficiently and accept modular inserts, they excel in high-density panels, DIN rail, backplane, and modular machinery. Because circular connectors self-align on rotation, they win where blind mating or field-wiring rotary alignment is needed.
Rectangular Connector Types and When to Use Each
Not every rectangular connector is a heavy duty connector. Some are designed for machine panels, while others are designed for PCB backplanes, aerospace electronics or rack systems. Use the rectangular form factor as the starting point, then confirm the application family.
| Rectangular Connector Type | Best Use | Why It Is Rectangular | Selection Note |
|---|---|---|---|
| Han-style heavy duty rectangular connector | Machine panels, robotics, cabinet pass-throughs, modular production cells | Rugged hood/base system with modular inserts | Main focus of this guide |
| Modular rectangular connector | Mixed power, signal, data and pneumatic layouts | One housing can combine multiple insert modules | Confirm insert compatibility and frame size |
| MIL-style rectangular connector | Defense, aerospace and high-reliability electronics | Compact high-density rectangular layout | Use only when MIL specification is actually required |
| PCB / backplane connector | Electronics racks, control boards and internal equipment interfaces | High pin density in a board-to-board or card-to-backplane structure | Different from industrial HDC housings |
| DIN 41612 / IEC 60603-2 connector | 19-inch racks, Eurocard systems and card-to-backplane connections | Standardized rectangular PCB connector geometry | Not a substitute for a sealed HDC housing |
Modular Inserts: Power, Signal, Data and Pneumatics
Modular inserts are the main reason rectangular HDC systems remain useful in machine-building. Instead of drilling multiple panel openings for separate power, signal, Ethernet and pneumatic lines, one rectangular housing can organize multiple media types inside a single service interface.
| Insert Function | Typical Use | What to Confirm |
|---|---|---|
| Power contacts | Motor, heater, actuator or machine power wiring | Rated current, voltage, conductor range and temperature rise |
| Signal contacts | Sensors, control loops and low-current circuits | Contact count, shielding and wiring method |
| Data modules | RJ45, industrial Ethernet or communication modules | Protocol, shielding, cable routing and EMC needs |
| Fiber modules | Noise-sensitive or long-distance communication | Fiber type, bend radius and module compatibility |
| Pneumatic modules | Air lines for automation and tooling | Tube size, pressure range and service access |
For wiring and termination details after the insert is selected, use the heavy duty wire connector guide.
Key technical specifications that must be evaluated
IP protection level – the most critical environmental specification
The IP (Ingress Protection) level is defined according to IEC 60529 and can be said to be the most important single specification for industrial rectangular connectors used in uncontrolled environments. It consists of two digits:
- The first digit (0-6): Protection against solid foreign matter (including dust)
- Second digit (0-8): Protection against liquid intrusion
| IP Rating | Solid Protection | Liquid Protection | Typical Use Case |
|---|---|---|---|
| IP20 | Finger-proof | None | Indoor control panels |
| IP54 | Dust partial | Water splash | General industrial |
| IP65 | Dust-tight | Water jets (any direction) | Outdoor machinery, enclosures |
| IP67 | Dust-tight | Immersion up to 1m / 30 min | Food processing, washdown areas |
| IP68 | Dust-tight | Continuous immersion (defined depth) | Subsea, submersible equipment |
For most industrial automation applications, IP65 is the recommended minimum protection level. Washing or food-grade environments require IP67 or higher.
Contact type and current rating
Modern heavy duty rectangular connectors and modular rectangular connectors support the use of a variety of contact types in a single housing:
- Power Contacts: 16A, 40A, 80A, 200A – Grading by blade / pin size
- Signal Contacts: low level transmission (1mV-5V range), usually gold-plated
- Coaxial Contacts: for radio frequency (RF) or high frequency signal channels
- Fiber Optic Contacts: Immune to EMI interference, suitable for high noise environments
- Pneumatic Contacts: Integrated gas or liquid channel (typical working pressure up to 6 bar)
Housing Material
| Material | Characteristics | Best Application |
|---|---|---|
| Die-cast zinc/aluminum | Impact-resistant, EMI shielding, grounding | Harsh industrial, automation |
| Thermoplastic (PA66, PBT) | Lightweight, corrosion-resistant, lower cost | General industrial, indoor |
| Stainless steel | Chemical-resistant, food-grade | Food & beverage, pharma |
For a deeper look at which shell alloys, platings, and coatings resist corrosion longest in salt, chemical, and washdown environments, see our anti-corrosion materials for industrial connectors guide.
Contact Plating
| Plating | Properties | Best For |
|---|---|---|
| Gold (Au) | Lowest contact resistance, highly corrosion-resistant | Low-current signal contacts, MIL-spec |
| Silver (Ag) | Good conductivity, lower cost than gold | Power contacts |
| Tin (Sn) | Economical, adequate for benign environments | Non-critical signal, consumer-grade |
Mating Cycles
Standard Industrial Connectors: 500-5,000 times
Overloaded version: up to 10,000 + times
MIL specification precision connector: depending on the specific specification file, usually more than 10,000 times
For frequent plug-in application scenarios – such as machine tools that require regular replacement of fixtures – it is important to clearly verify the plug-in life rating of the connector.
Compliance standard for industrial rectangular connectors
Compliance with recognized international standards is an uncompromising bottom line in regulated industries. The main criteria include:
| Standard | Scope |
|---|---|
| IEC 61984 | General performance requirements for industrial connectors |
| IEC 60529 | IP ingress protection classification system |
| IEC 61076-4 | Connectors for electronic equipment — PCB types |
| MIL-DTL-24308 | Rectangular electrical connectors, military (sub-D style) |
| MIL-C-83513 | Micro-D rectangular connectors |
| UL 1977 | Data, signal, control, and service application connectors |
| EN 45545 | Fire behavior requirements for railway applications |
| RoHS / REACH | European environmental compliance — hazardous substance restriction |
Practical application scenarios in various industries
Manufacturing and Industrial Automation
The Han series of heavy-duty rectangular connectors dominate the world’s robotic arms, CNC machining centers, and conveying systems. The Quick-release shield design allows the entire set of cable assemblies to be plugged in seconds – with a significant quantifiable advantage in reducing planned maintenance downtime.
Rail Transit and Transportation
Locomotives and traction control systems require connectors to meet EN 45545 fire behavior standards. Rectangular connectors for rail transit must meet the precise limits of flame spread, smoke density and toxic gas emissions.
Defense and aerospace
MIL-specific rectangular connectors provide mission-critical performance in extreme temperature ranges (−65°C to +200°C) and harsh vibration conditions. It is widely used in radar system, missile guidance electronic equipment, military vehicle CAN bus wiring and shipboard communication system.
Renewable energy
The wind turbine nacelle requires modular rectangular connectors to have a service life of more than 20 years and can withstand temperature cycles from −40°C to +70°C, ultraviolet radiation, and high altitude humidity. The solar inverter system relies on PCB rectangular connectors to achieve high-density internal wiring.
Food and Beverage Processing
The connector with IP67 / IP68 protection grade, stainless steel or food-grade thermoplastic shell can resist the erosion of strong cleaning agents, high-pressure washing and disinfection chemicals required in the food safety environment.
With regard to the comprehensive cabling and termination specifications, the IEC 60352 non-welding connection standard provides an authoritative reference.
Coding and keying: how a rectangular connector blocks a mismate
A heavy duty connector stops a wrong connection mechanically, before a single contact carries current. As of 2026, IEC 61984 — the safety standard for connectors rated above 50 V — builds this on two ideas: a protective earth contact that mates first and breaks last, and coding that keeps the wrong plug out of the wrong housing.
- PE first-mate, last-break. The central PE contact is longer than the signal and power pins, so earth is made before they touch and is the last connection to part on withdrawal.
- Coding pins and keyways. Guide pins and coded hoods let you run several connectors of the same frame size on one machine that physically cannot cross-mate — a 400 V power drop will not enter a 24 V control socket.
- No mating under load. Han E and equivalent inserts are not rated to make or break under electrical load; per HARTING and ILME insert datasheets, you de-energize the circuit before plugging or unplugging.
None of this is optional on a floor where a maintenance tech reconnects a dozen identical-looking housings against the clock. Coding turns “looks the same” into “cannot connect wrong.” Verchil HDC housings use the same coding-pin layout and PE-first contact geometry as the Han standard, which is what lets them serve as a drop-in heavy duty connector on tooling already built around Harting or ILME parts.
How to Specify an Industrial Rectangular Connector
Step 1 — Define the Panel Interface
Confirm whether the connector is mounted on a machine wall, control cabinet, junction box or cable-to-cable interface. This decides the base type, hood style and cable entry direction.
Step 2 — Choose the Frame Size
Select the frame size according to the required insert space, panel footprint and future expansion needs. Do not choose the frame size by pin count alone if the connector also needs Ethernet, fiber or pneumatic modules.
Step 3 — Select the Insert Layout
Group circuits by function: power, signal, data, fiber or pneumatic. Keep high-current power and sensitive data modules separated where the insert system and EMC requirements call for it.
Step 4 — Confirm Locking and Cable Entry
Choose the locking method and cable entry direction according to vibration level, service access and cable routing. A side-entry hood may solve space problems, while a top-entry hood may simplify straight cable routing.
Step 5 — Send the Configuration for Review
Before ordering, confirm the frame size, hood type, base type, insert layout, cable diameter, target IP rating and termination method. This avoids mismatched hoods, bases and inserts.
Four connection types of industrial rectangular connectors: how to classify by use?
In addition to the shape and protection level, industrial rectangular connectors can also be divided into the following four categories according to the electrical connection objects, which directly determines the selection direction:
Board-to-Board Connection
Two PCBs are connected directly to each other without cables. It is suitable for internal systems with extremely limited space. Parallel or vertical (Mezzanine) layout can be used to eliminate the problem of internal wiring clutter. It is common in the stacked interconnection between the main board and the sub board of the industrial controller.
Wire-to-Board Connection
Connecting wires or cables to a PCB is the most common form of connection in devices such as servo drives and frequency converters. The cross-sectional area of the wire, the rated current of the contact and the contact retention force should be considered in the selection.
Wire-to-Wire Connection
Connectors with both ends connected by wires are widely used for cable extension between cabinets and interconnection between devices. A single housing of such connectors can support up to about 50 circuits. The number of circuits, wire diameter and mating gender (pins / jacks) should be confirmed when selecting the type.
Panel Feedthrough / Bulkhead connection
One side of the connector is fixedly installed on the cabinet or equipment panel, and the other side provides a pluggable interface. The sealed mounting surface can effectively block dust and liquid and provide excellent Strain Relief for cables. It is a standard solution for modular rapid assembly in production lines and control cabinets.
5 termination methods for industrial rectangular connectors: Which is best for your application?
The contact termination determines the mechanical fixation and electrical connection between the wire and the contact, which directly affects the connection reliability, assembly efficiency and on-site maintenance convenience. There are five commonly used termination methods for industrial rectangular connectors:
A special crimping tool is used to mechanically press the metal contacts onto the wire sheath and conductor to form a gas-tight non-oxidative connection. This is the most mainstream termination method in the industrial field, suitable for mass automated production, high contact density, strong vibration resistance, and reliability comparable to welding.
- Advantages: high automation, good consistency, resistance to harsh environments
- Disadvantages: special crimping tool is needed; error crimping is not easy to judge by the naked eye
- Most suitable for: automation machinery, automobile industry, mass production of wiring harness
The peeled wire was inserted into the contact cavity, and the internal screw fixation was tightened. This is one of the oldest termination methods. It does not need special tools and can be completed by ordinary screwdriver, which is suitable for frequent demolition and modification on site.
- Advantages: no need for special tools, on-site operability, repeated disassembly and assembly
- Disadvantages: the screw may be loose in the vibration environment; long operating time
- Most suitable for: panel installation connector, control cabinet wiring, lighting system
After the wire is inserted, it is automatically clamped by the built-in spring, and the wiring can be completed without tools. Use a small tool to unlock the shrapnel when pulling out the wire. This method provides extremely high vibration resistance and low voltage drop, and is increasingly replacing screw termination for industrial machinery.
- Advantages: no tool operation, excellent vibration resistance, fast wiring speed
- Disadvantages: unlocking requires gadgets ; there are certain restrictions on the cross-sectional area of the wire
- Most suitable for: robotics, high-vibration machinery, energy systems, industrial automation.
There is no need to strip the insulation layer of the wire, and the sharp blade built in the connector automatically pierces the insulation jacket when the wire is inserted, forming an airtight contact with the conductor. IDC is compatible with solid lines, multi-strand lines and flat lines, and is highly suitable for automated mass assembly.
- Advantages: no stripping, no special tools, the fastest speed
- Disadvantages: only applicable to specific wire diameter range; not suitable for frequent plug-ins occasions
- Most suitable for: computer equipment wiring termination, mass automated assembly
The wire is soldered to the solder cup or solder tail of the contact to form a hermetic electrical connection while protecting the copper conductor from oxidation. Soldering is a labor-intensive process, which is suitable for small batch production or occasions where contact density is extremely high and other termination methods cannot be implemented. PCB welding is also subdivided into three ways: through-hole welding (THT), surface mount (SMT) and pin-in-hole welding (PIP).
- Advantages: the most reliable connection, good air tightness, high mechanical strength PCB installation
- Disadvantages: high labor intensity, not easy to rework on site, SMT resistance to lateral force is weaker than THT
- Most suitable for: military / aerospace high reliability applications, PCB on-board connection, small batch customization assembly
Installation and maintenance best practices
Tighten the shell screw according to the torque specification – too tight will cause the shell to crack, and too loose will damage the IP sealing performance.
Using the manufacturer’s specified plug-and-pull tool – do not force the contact by hand, bent pins can lead to intermittent faults that are difficult to troubleshoot.
Inspect the gaskets every time they are regularly maintained – especially for applications in outdoor or flush environments.
Apply approved conductive grease to electrical contacts in high humidity applications to suppress oxidation accumulation.
Clear and permanent marking of the connector to prevent mis-insertion during on-site maintenance is a common cause of equipment damage.
Unplugged connectors should be stored with a protective cover to prevent contamination of the sealing surface.
| Termination Type | Special Tool Required | Vibration Resistance | Rewirability | Automation Compatibility | Typical Application |
|---|---|---|---|---|---|
| Crimp | Yes — Crimping Tool | High | Low | Excellent | Automated wire harness, automotive |
| Screw | No | Medium | High | Low | Control cabinets, panel wiring |
| Spring Clamp | No (release tool for removal) | Excellent | High | Medium | Robotics, energy systems |
| IDC | No | Medium | Low | High | Flat cable, high-volume assembly |
| Solder | Yes — Soldering Station | Excellent | Very Low | Medium | Military / aerospace, PCB mount |
Frequently Asked Questions
What is the difference between industrial rectangular connectors and circular connectors?
Industrial rectangular connectors are better when a panel interface needs high contact density, modular inserts and mixed power/signal/data wiring. Circular connectors are better when the equipment needs a compact cable-to-cable form, round shell geometry or easier self-alignment in tight spaces.
IP Rating Is a Sealing Decision, Not a Shape Decision
A rectangular connector can be IP-rated only when the complete assembly — hood, housing, gasket, locking lever and cable gland — is correctly matched and installed. The rectangular shape helps organize the interface, but the IP rating depends on the sealing system. For gasket, cable gland and IP65–IP69K selection, use the heavy duty waterproof connector guide. For a full explanation of IP codes, see the IP ratings guide.
Is MIL rectangular connector suitable for commercial industrial applications?
Apply. MIL connectors are frequently used in high reliability commercial applications. Compared with standard industrial connectors, its cost is higher, but this premium is reasonable when downtime or failure brings significant safety or economic losses.
Can modular rectangular connectors be reconfigured after installation?
In many modular HDC systems, inserts can be changed when the connector is powered off, disconnected and serviced according to the manufacturer’s instructions. The housing size, module frame and insert family must remain compatible, so reconfiguration should be checked against the supplier’s assembly diagram.
Is a Han-style connector the same as an industrial rectangular connector?
Han-style connectors are one major family of industrial rectangular connectors. The term usually refers to rectangular heavy duty connector systems with hood, base, insert and locking components. Other rectangular connectors, such as DIN 41612 backplane connectors, are rectangular but not Han-style HDCs.
What information is needed to specify a rectangular HDC housing?
Prepare the frame size, panel cutout or mounting space, cable entry direction, hood style, base type, locking method, target IP rating and insert layout. If power, signal and data are mixed, include the number of contacts and conductor size for each circuit group.
Can different brands of rectangular hoods, bases and inserts be mixed?
Do not assume full compatibility only from similar frame names. Some insert patterns may appear similar, but gasket compression, tolerances and locking geometry can differ by manufacturer. For IP-rated or safety-critical assemblies, keep hood, base and insert within one verified system unless the manufacturer confirms compatibility.
Are DIN 41612 connectors industrial rectangular connectors?
DIN 41612 / IEC 60603-2 connectors are rectangular connectors used mainly for printed boards, Eurocard systems and backplanes. They are not the same as heavy duty rectangular HDC housings used for machine panels and field wiring.
Conclusion
Industrial rectangular connectors should be selected as a mechanical and modular interface first. The key questions are housing size, hood type, base style, insert layout, cable entry direction, locking method and panel mounting space. Once the rectangular architecture is clear, current rating, IP sealing and termination method should be confirmed from the matching product datasheet and related Verchil guides.
For general HDC selection, use the heavy duty connector selection guide. For waterproof sealing, use the heavy duty waterproof connector guide. For wiring and termination, use the heavy duty wire connector guide. To review a rectangular HDC configuration, contact Verchil with the frame size, insert layout, cable diameter, mounting style and operating environment.
