PG 7, PG 13.5 and PG 63 Cable Glands: Sizes, Uses, and Selection Tips

Whether you’re dealing with leaks in outdoor server racks or cable damage caused by vibration, you’ve almost certainly encountered PG series cable glands.

PG cable glands are available in a wide range of sizes, and selecting the correct one is not simply a matter of preference. Factors such as cable diameter, installation environment, and enclosure design all play a role.

Understanding the differences between common sizes like PG 7, PG 13.5, and PG 63 can help ensure proper sealing, strain relief, and long-term reliability. Next, we’ll detail their specifications, application scenarios, and common selection pitfalls.

What Are PG-Series Cable Glands?

PG series cable glands are commonly used cable entry assemblies in industrial electrical installations. They are designed to provide a secure, sealed connection between the cable and the equipment housing.

In practical applications, PG cable glands can be used to:

• Secure cables to housings such as control panels, junction boxes, and motor housings
• Protect cable entry points from dust, moisture, and corrosive environments (many designs meet IP68 protection standards)
• Reduce mechanical stress caused by tension or vibration, helping to prevent damage to internal conductors
• Comply with widely recognized compliance standards, including UL, CE, and RoHS

Unlike metric (M series) cable glands, PG connectors are sized based on thread diameter and pitch, not millimeters. This sizing system has made the PG series a long-standing standard in European electrical installations and is widely used in the global industrial market.

What Are PG 7, PG 13.5 and PG 63 Cable Glands?

PG cable glands are widely used in industrial control panels, junction boxes, and electrical equipment where reliable sealing and stress relief are required.

The main differences between PG 7, PG 13.5, and PG 63 are their sizes and cable load capacities. PG 7 is typically used for small-diameter signal or control cables, PG 13.5 covers a wide range of standard industrial cabling, while PG 63 is designed for large, heavy-duty power cables. These three sizes of cable glands cover virtually all applications in industrial environments.

Parameter	PG 7	PG 13.5	PG 63
Thread Outside Diameter	12.5 mm	20.4 mm	57.3 mm
Cable Diameter Range	3–7 mm	6–12 mm	38–54 mm
Wrench Size	16 / 18 mm	24 / 27 mm	85 / 95 mm
Typical Material	Nylon PA66 + Nitrile Rubber (NBR)	Brass + EPDM Rubber	304 Stainless Steel
Operating Temperature	−40°C to 100°C	−30°C to 100°C	−40°C to 120°C (industrial grade)
Ingress Protection Rating	IP68 (up to 10 m submersion)	IP68 with EMC shielding	IP68, salt spray resistant
Key Certifications	UL 94 V-2 flame retardant	RoHS, CE	ISO 9001

Where Are PG-Series Cable Glands Typically Used?

PG-series cable glands are widely used across industrial environments where secure cable entry, environmental sealing, and mechanical protection are required. Different PG sizes are suited to different cable diameters and operating conditions. The following examples show how PG 7, PG 13.5, and PG 63 are commonly applied in real-world installations.

PG 7 Application: Compact Sensors in Food Processing

In a food processing facility, PG 7 cable glands are used to seal temperature sensor cables installed along a conveyor system. Their compact form factor fits easily into the limited space of sensor housings, while the IP68 sealing protects against moisture, washdown water, and cleaning chemicals commonly used in food-grade environments.

PG 13.5 Application: Inverter Connections in Solar Installations

A utility-scale solar power plant uses PG 13.5 nylon cable glands for inverter connections within electrical panels. The EPDM sealing grommets maintain reliable performance across wide temperature swings, and the gland design allows for fast, tool-free installation, helping reduce panel assembly time on site.

PG 63 Application: Heavy-Duty Power Cables in Wind Turbines

In wind turbine manufacturing, stainless steel PG 63 cable glands are selected for connecting generator power cables. The metal housing provides strong resistance to salt spray and harsh outdoor conditions, while the large clamping range accommodates high-capacity power cables up to 50 mm in diameter, ensuring long-term reliability in offshore and coastal installations.

How to Choose the Right Cable Gland?

Selecting the correct cable gland is not just a sizing exercise. Mismatched dimensions, improper materials, or overlooked temperature limits can quickly lead to seal failure, cable damage, and costly downtime. Below are three common mistakes seen in industrial installations and how to avoid them.

Overlooking Cable Diameter Compatibility

Common Mistake

Using a PG 13.5 cable gland for a 5 mm cable, which results in a loose seal, or forcing a PG 7 gland onto a 9 mm cable, creating excessive compression.

What Happens

Poor sealing often leads to moisture ingress, while excessive clamping pressure can damage the cable jacket. In many cases, leaks or insulation failures appear within a few months of installation.

Best Practice

Always select the gland based on the actual outer cable diameter, not the conductor size. For example, PG 13.5 is typically suitable for cables in the 6–12 mm range. Choose PG 7 for smaller cables and move up to larger PG sizes when the cable diameter increases.

Selecting the Wrong Material for the Environment

Common Mistake

Installing nylon (PA66) PG 63 cable glands in coastal wind turbine applications where salt spray and high humidity are present.

What Happens

Nylon housings degrade more quickly in corrosive environments, leading to cracked glands, compromised seals, and unplanned maintenance. In severe cases, motor repairs can exceed $8,000.

Best Practice

Match the gland material to the operating environment:

• Nylon (PA66): Dry, indoor locations such as control cabinets
• Brass: Industrial settings with moderate moisture or chemical exposure
• 304 stainless steel: Harsh conditions including offshore, coastal, or chemical processing environments

Ignoring Temperature Limits

Common Mistake

Using a standard PG 13.5 cable gland in a boiler room where ambient temperatures reach 120°C.

What Happens

Sealing inserts soften or deform at elevated temperatures, increasing the risk of electrical shorts and loss of ingress protection.

Best Practice

Check both static and dynamic temperature ratings before installation. While many cable glands are rated for −40°C to 100°C under static conditions, their dynamic rating, when the cable is moving, may be limited to −20°C to 80°C. Always verify the rating against real operating conditions.

PG vs. Metric Cable Glands

Across Europe and other international markets, there has been a steady shift from traditional PG-thread cable glands to metric (M-series) glands. In many cases, metric sizes are now used as functional replacements, such as M12 for PG 7, M20 for PG 13.5, and M63 for PG 63. The two systems, however, differ in sizing logic, standards, and typical use cases.

Feature	PG Series	Metric (M Series)
Installed Base	Widely used in legacy and German-made equipment	Increasingly common in new installations
Standards	Legacy DIN standards	IEC 62444
Sizing Method	PG number does not directly indicate thread diameter	Thread size matches nominal diameter (e.g., M20 = 20 mm)
Ease of Selection	Requires reference to sizing charts	More intuitive and easier to specify
Cost Considerations	Often lower for nylon glands	Comparable for brass and stainless steel

Conclusion

PG 7, PG 13.5, and PG 63 cable glands each serve distinct roles in industrial cable management. Selecting the right size and material, based on cable diameter, installation conditions, and environmental exposure helps ensure a secure seal and long-term performance.

If you’re looking for custom PG cable glands or fittings, our engineering team can help with selection and customisation. Free samples are available, and we offer worldwide shipping with typical lead times of up to seven days.