When selecting brass cable glands for industrial electrical systems, one of the most important decisions is choosing the correct thread standard. Among the most widely used cable gland thread types worldwide, Metric brass cable glands and PG brass cable glands are the two most common options found in industrial machinery, automation systems, control cabinets, renewable energy projects, and electrical enclosures.

At first glance, Metric and PG brass cable glands may appear very similar. Both are designed to secure and seal cables while providing strain relief and environmental protection. However, the differences in thread design, compatibility, installation standards, sealing behavior, and regional usage can significantly impact installation reliability and procurement efficiency.

For engineers, OEM manufacturers, panel builders, EPC contractors, distributors, and maintenance teams, selecting the wrong thread type can create serious problems such as:

• Thread mismatch

• Water leakage

• Improper sealing

• Cross-thread damage

• Installation delays

• Increased maintenance costs

• Equipment failure

This article provides a detailed comparison between Metric brass cable glands and PG brass cable glands, helping industrial buyers understand the technical differences, application scenarios, and selection strategies for modern electrical systems.

What Is a Metric Brass Cable Gland?

A Metric brass cable gland uses ISO metric thread standards and is identified by the letter “M” followed by the thread diameter in millimeters, such as:

• M12

• M16

• M20

• M25

• M32

Metric cable glands are manufactured according to international metric standards such as EN 62444 and are now considered the global standard for most modern industrial installations.

Metric brass cable glands are widely used in:

• Industrial automation

• Renewable energy systems

• Electrical control cabinets

• Railway systems

• Telecommunications

• Data centers

• Marine engineering

• Outdoor electrical installations

Their popularity comes from excellent compatibility with modern metric-based industrial equipment worldwide.

What Is a PG Brass Cable Gland?

PG stands for “Panzer-Gewinde,” a German thread standard originally developed for armored conduit systems. PG brass cable glands are identified by thread sizes such as:

• PG7

• PG9

• PG11

• PG13.5

• PG16

• PG21

PG cable glands follow older German DIN thread standards and were historically common across European industrial machinery and electrical systems.

Although many modern systems now use metric threads, PG cable glands remain widely used for:

• Legacy European machinery

• Retrofitting projects

• Existing automation systems

• Older industrial control cabinets

• Maintenance replacement applications

In many factories worldwide, older European equipment still relies heavily on PG thread standards.

Main Difference Between Metric and PG Brass Cable Glands

The biggest difference lies in the thread geometry and standardization system.

Metric Brass Cable Gland Threads

Metric cable glands use:

• ISO metric thread standard

• 60° thread angle

• Millimeter-based sizing

• Fine thread design

This creates:

• Precise thread engagement

• Better sealing consistency

• Strong mechanical stability

PG Brass Cable Gland Threads

PG cable glands use:

• German DIN standard

• 80° thread angle

• Non-metric historical sizing system

• Rounded thread profile

PG threads were designed primarily for older industrial conduit systems.

Metric vs PG Brass Cable Gland Thread Structure Comparison

The two thread systems are not interchangeable. Forcing a Metric gland into a PG opening or vice versa can permanently damage the enclosure threads and compromise waterproof sealing.

Why Metric Brass Cable Glands Became the Global Standard

Over the past two decades, Metric brass cable glands have become dominant in most new industrial projects.

Main Reasons Include:

Better International Standardization

Metric systems align with modern global manufacturing standards.

Easier Global Sourcing

Metric cable glands are easier to source internationally because most manufacturers now prioritize metric production.

Improved Thread Precision

Metric threads provide more accurate engagement and stable sealing performance.

Better Compatibility With Modern Equipment

Most new industrial equipment uses metric entry holes and metric conduit systems.

Because of these advantages, many industries have gradually shifted from PG to Metric systems.

Why PG Brass Cable Glands Are Still Widely Used

Despite the growth of metric systems, PG brass cable glands remain important in many industries.

Existing Installed Base

Thousands of factories worldwide still operate older European machinery with PG-threaded cable entries.

Replacing the entire enclosure system is often expensive and impractical.

Maintenance and Retrofitting

Maintenance teams frequently require PG cable glands for:

• Equipment repair

• Spare parts replacement

• System upgrades

• Industrial retrofitting

Compatibility With Older German Equipment

Many legacy European machines were specifically designed for PG thread standards.

For these systems, PG cable glands remain the correct and safest option.

Sealing Performance Comparison

Both Metric and PG brass cable glands can achieve high waterproof ratings when properly manufactured.

Metric Brass Cable Glands

Advantages include:

• More precise thread engagement

• Better compression consistency

• Improved sealing accuracy

• Easier torque control

High-quality metric cable glands commonly achieve:

• IP66

• IP67

• IP68

The finer thread structure improves long-term sealing reliability.

PG Brass Cable Glands

PG cable glands can also provide reliable sealing, especially in legacy systems.

However, because PG threads are coarser and less standardized globally, sealing consistency may vary more between manufacturers.

In modern waterproof applications, Metric cable glands are generally preferred.

Installation Compatibility Comparison

Metric Brass Cable Glands

Best suited for:

• Modern industrial equipment

• New automation projects

• Renewable energy systems

• International EPC projects

• Global export machinery

Metric glands simplify procurement because metric thread standards are widely accepted internationally.

PG Brass Cable Glands

Best suited for:

• Existing European systems

• Replacement projects

• Older machinery maintenance

• Legacy control cabinets

Using the correct matching thread type is critical for maintaining enclosure integrity.

Cable Size Selection Differences

Metric cable gland sizing directly corresponds to thread diameter.

For example:

• M20 ≈ 20 mm thread diameter

• M25 ≈ 25 mm thread diameter

This makes metric sizing more intuitive.

PG sizing is less straightforward because PG numbers historically relate more closely to cable capacity rather than actual thread diameter.

For example:

This can create confusion for inexperienced buyers.

Corrosion Resistance Comparison

The corrosion resistance of both gland types depends more on material quality and surface finishing than thread type.

High-quality Metric and PG brass cable glands usually feature:

• Nickel-plated brass

• Corrosion-resistant finishes

• UV-resistant sealing inserts

• Salt spray resistance

For outdoor and marine environments, premium nickel-plated brass construction is strongly recommended regardless of thread standard.

Which Industries Prefer Metric Brass Cable Glands?

Metric cable glands dominate in:

Renewable Energy

Solar and wind systems typically follow metric standards.

Industrial Automation

Modern automation equipment is primarily metric-based.

Global OEM Manufacturing

International machine exports favor metric compatibility.

Data Centers and Telecommunications

Modern infrastructure projects commonly use metric systems.

Smart Manufacturing

Industry 4.0 equipment generally adopts metric thread standards.

Which Industries Still Use PG Brass Cable Glands?

PG cable glands remain common in:

Legacy European Factories

Older German and European machines still require PG compatibility.

Industrial Retrofitting Projects

Replacing only damaged components often requires matching PG threads.

Equipment Maintenance

Maintenance teams frequently source PG glands for spare parts replacement.

Older Automation Systems

Existing control cabinets may still use PG entry holes.

Common Procurement Mistakes

Mistake 1: Assuming Metric and PG Threads Are Compatible

They are not interchangeable.

Incorrect installation can cause:

• Cross-threading

• Water ingress

• IP rating failure

• Permanent enclosure damage

Mistake 2: Choosing Based Only on Appearance

Metric and PG glands may visually appear similar, but thread geometry is completely different.

Mistake 3: Ignoring Regional Equipment Standards

Some imported European equipment still requires PG cable glands.

Always verify thread specifications before purchasing.

How to Choose Between Metric and PG Brass Cable Glands

Choose Metric Brass Cable Glands If:

• The equipment is modern

• The project follows international standards

• Global sourcing flexibility is important

• Long-term scalability matters

• New installations are being designed

Choose PG Brass Cable Glands If:

• The equipment already uses PG threads

• You are repairing legacy European machinery

• Existing enclosures are PG-threaded

• Retrofitting compatibility is required

Future Trend: Metric Cable Glands Continue Expanding

Global industrial trends clearly show increasing adoption of Metric cable glands.

Reasons include:

• International standardization

• Easier procurement

• Improved compatibility

• Better manufacturing consistency

• Simplified engineering design

However, PG cable glands will likely remain important for maintenance and legacy system support for many years due to the enormous installed equipment base worldwide.

Final Thoughts: Compatibility Is More Important Than Price

The decision between Metric brass cable glands and PG brass cable glands should primarily focus on system compatibility rather than cost alone.

Metric cable glands provide better standardization, easier international sourcing, and stronger compatibility with modern industrial systems. They are now the preferred choice for most new projects worldwide.

PG cable glands, meanwhile, remain essential for maintaining and upgrading existing European machinery and legacy industrial systems.

For procurement professionals and engineers, the most important factor is ensuring that the thread type exactly matches the enclosure design and project specifications. Even a high-quality brass cable gland will fail if the wrong thread standard is selected.

YDT provides both Metric brass cable glands and PG brass cable glands with precision machining, reliable sealing performance, customizable specifications, and professional support for industrial cable management projects worldwide.