Introduction
When routing cables into electrical enclosures, control panels, or machinery, selecting the correct cable gland thread type is non-negotiable. Forcing the wrong thread type into a pre-drilled hole will strip the threads, destroy the environmental seal (IP67/IP68), and lead to potential equipment failure from water or dust ingress.
The two most common thread standards in the industrial world are Metric (M Thread) and PG (Panzergewinde). But how do they differ, and which one does your project require?
In this comprehensive guide, we will break down the technical differences between Metric and PG cable glands to help engineers and buyers make the right choice.
What is a Metric Cable Gland (M Thread)?
Metric cable glands are the modern global standard for electrical installations. They are manufactured according to ISO metric standards (EN 62444) and feature a straight, fine thread.
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Thread Angle: 60 degrees.
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Identification: Always denoted by an “M” followed by the outer diameter in millimeters (e.g., M20, M25, M32).
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Performance: Because of the fine thread pitch, Metric glands offer highly precise engagement, resulting in superior mechanical stability and excellent waterproof sealing.
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Status: They are the default choice for all new machinery, automation systems, and global electrical equipment.
Explore our complete range of Nylon Metric Cable Glands.
What is a PG Cable Gland (Panzer-Gewinde)?
“Panzergewinde” translates to “armor thread” in German. Developed in Germany, PG threads were the standard across European electrical machinery for decades. They follow the older DIN 40430 standard.
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Thread Angle: 80 degrees.
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Identification: Denoted by “PG” followed by a nominal number that roughly corresponds to the maximum cable diameter it can accommodate (e.g., PG7, PG13.5, PG21).
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Performance: Features a rounded, coarser thread profile. While it provides a very reliable grip for thicker, heavy-duty cable jackets, it lacks the fine-tuning precision of Metric threads.
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Status: While largely replaced by Metric in new designs, PG glands are still heavily manufactured and required for retrofitting, repairing, and maintaining legacy European equipment.
Need parts for older equipment? Browse our PG Standard Cable Glands .
Key Technical Differences: Metric vs. PG Table
To help you understand the structural differences at a glance, here is a technical comparison table:
| Technical Feature | Metric Cable Glands (M) | PG Cable Glands (PG) |
| Standard/Specification | ISO Metric / EN 62444 | German DIN 40430 |
| Thread Profile (Angle) | 60° (Sharp, straight, fine) | 80° (Rounded, coarse) |
| Size Notation | M12, M16, M20, M25, M32… | PG7, PG9, PG11, PG13.5… |
| Size Precision | Smaller step increments | Larger step increments |
| Sealing Capability | Exceptional (Easily achieves IP68) | Good (Adequate for standard use) |
| Primary Use Case | All new global installations | Legacy systems, European machinery |
How to Choose Based on Application
Selecting between the two usually comes down to the equipment you are working with:
1. For New Equipment and Global Projects (Choose Metric)
If you are designing a new control panel or manufacturing machinery for the international market, always select Metric glands. They comply with modern international standards, ensuring your equipment passes global safety and compliance inspections.
2. For Maintenance and Retrofitting (Choose PG)
If you are replacing a broken gland on a 15-year-old German CNC machine, you must use a PG gland. The enclosure is already tapped with a PG thread. Attempting to force a Metric gland into a PG hole will destroy the threads.
3. When Handling Thick or Reinforced Cables
Due to their larger thread increments and deeper profile, PG cable glands often provide robust clamping force for exceptionally thick or heavily armored cable jackets.
4. The “Mismatch” Solution: Thread Adapters
What if your modern enclosure has an M20 hole, but you need to fit a legacy PG13.5 sensor cable? Instead of drilling new holes, you can use Thread Adapters / Reducers (e.g., Metric to PG, or PG to Metric). This is a common and safe practice in industrial upgrades.
Frequently Asked Questions (FAQs)
Are Metric and PG cable glands interchangeable?
No, they are strictly not interchangeable. A Metric thread has a 60° angle, while a PG thread has an 80° angle. Forcing one into the other will strip the threads and ruin the IP waterproof rating. You must use a matching thread or a specialized thread adapter.
Which provides better waterproof sealing?
Metric cable glands generally offer more precise sealing. Their fine straight threads allow the locknut and O-ring to compress evenly against the enclosure, making it easier to achieve true IP68 waterproof ratings.
Do both types come in metal and plastic?
Yes. Both Metric and PG cable glands are widely manufactured in Nylon PA66 (plastic), Nickel-plated Brass (metal), and Stainless Steel to suit different environmental requirements.
Conclusion
Understanding the differences between Metric and PG threads is the first step. Sourcing reliable, certified components is the next.
At Niuli Electric (NLZD), we manufacture premium Metric, PG, and NPT cable glands in Nylon, Brass, and Stainless Steel. Our products are rigorously tested to ensure flawless thread engagement and IP68 waterproof protection for your most critical installations.
Ready to order or need a custom solution?
Contact us today for a free sample and bulk pricing!
