PG9 Cable Gland: Complete German Thread Size and Specifications Guide

PG9ケーブルグランドドイツのネジサイズと仕様ガイド

The PG9 cable gland represents one of the most widely specified mid-range PG thread sizes in industrial electrical installations across Europe and global markets. As a German thread standard defined under DIN 46320, PG9 cable glands accommodate cable diameters from 4mm to 8mm, making them ideal for control panel wiring, sensor connections, and light industrial equipment applications. Understanding PG9 cable gland German thread specifications ensures proper component selection, installation compliance, and long-term system reliability. This comprehensive reference guide covers dimensional standards, material options, conversion equivalents, and practical application scenarios to help engineers, procurement specialists, and installation technicians specify the correct PG9 cable gland for their specific requirements.

Understanding PG Thread Standards and DIN 46320

PG (Panzergewinde) thread designations originated in Germany as a parallel thread system specifically designed for electrical cable gland applications. Unlike metric threads which use millimeter-based sizing, PG threads employ a numerical designation (PG7, PG9, PG11, etc.) that doesn’t directly correspond to the thread’s outer diameter. The PG9 designation specifically refers to a thread with an outer diameter of 15.2mm and a thread pitch of 1.41mm.

The governing standard for PG cable glands is DIN 46320, which establishes construction requirements, dimensional tolerances, and performance criteria. This standard specifies that PG9 cable glands must provide secure strain relief, environmental sealing, and electrical continuity where required. Compliance with DIN 46320 ensures interchangeability between manufacturers and verifiable performance characteristics for procurement specifications.

Key PG9 Thread Specifications

The technical specifications for PG9 cable gland German thread are:

  • Thread designation: PG9
  • Outer diameter: 15.2mm
  • Thread pitch: 1.41mm (approximately 18 threads per inch)
  • Panel cutout diameter: 15.2mm + 0.2mm tolerance
  • Thread engagement length: Typically 5-6mm depending on gland design
  • Thread angle: 80° flank angle (wider than metric 60° or NPT 60°)

The PG9 thread features parallel (straight) threads on both male and female components, unlike NPT tapered threads. This parallel design allows for easier assembly and disassembly while maintaining seal integrity through compression gaskets rather than thread interference.

PG9 Cable Diameter Range and Sizing

The defining characteristic of PG9 cable glands is their accommodation of cable outer diameters ranging from 4mm to 8mm. This mid-range capacity makes PG9 ideal for:

  • Control wiring: Multi-conductor cables for PLC inputs, relay controls, and sensor signals
  • Instrumentation cables: Thermocouple wire, RTD sensor cables, and measurement circuits
  • Communication cables: Industrial Ethernet, RS-485, and fieldbus networks
  • Power distribution: Low-voltage DC power supplies and LED lighting circuits
  • Automation sensors: Proximity sensors, photoelectric sensors, and limit switches

Proper cable sizing within the PG9 range ensures adequate compression seal engagement. Cables smaller than 4mm require reducing bushings or alternative gland sizes (PG7), while cables exceeding 8mm necessitate upgrading to PG11 or larger specifications.

Cable Range Verification Process

Before specifying PG9 cable glands, measure the cable outer diameter including any jacket, sheath, or armor layers:

  1. Use precision calipers to measure cable OD at multiple points
  2. Account for cable ovalness by taking maximum dimension
  3. Add 0.5-1mm for manufacturing tolerances and compression allowance
  4. Verify the resulting dimension falls within 4-8mm range
  5. Confirm cable construction (unarmoured, braided shield, etc.) matches gland sealing design

Cables with irregular cross-sections, such as flat ribbon cables or multi-core bundles, may require special PG9 gland variants with elongated seal openings.

Material Options for PG9 Cable Glands

PG9 cable glands are manufactured in multiple material configurations to suit different environmental and mechanical requirements.

Nickel-Plated Brass PG9 Glands

Nickel-plated brass represents the standard material for industrial PG9 cable glands. These metal glands offer:

  • Excellent mechanical strength for vibration resistance
  • Corrosion protection through nickel plating (typically 5-8 microns thick)
  • Temperature range from -40°C to +100°C
  • Electrical continuity for EMI shielding and grounding
  • IP65 or IP68 rating when properly installed with sealing washers
  • Flame resistance and outdoor UV stability

Brass PG9 glands comply with DIN 46320-C4-MS specifications and are suitable for industrial control panels, motor junction boxes, and outdoor electrical enclosures.

Nylon/Polyamide PG9 Cable Glands

Nylon 66 (polyamide) PG9 cable glands provide a lightweight, corrosion-proof alternative for non-metallic applications. Characteristics include:

  • Chemical resistance to oils, solvents, and cleaning agents
  • Non-conductive for isolation requirements
  • Temperature range from -20°C to +80°C (standard grades)
  • IP54 to IP68 ratings depending on seal design
  • Lower cost than metal equivalents
  • Available in multiple colors (black, gray, light gray) for coding

Nylon PG9 glands are ideal for plastic enclosures, food processing equipment, and applications where electrical isolation or weight reduction is critical.

Stainless Steel PG9 Glands

For harsh chemical, marine, or high-temperature environments, stainless steel 316 PG9 cable glands offer maximum corrosion resistance. These premium glands withstand:

  • Saltwater and marine atmospheres
  • Acidic or alkaline chemical exposures
  • Temperature extremes up to +200°C (special high-temp seals)
  • High-pressure washdown (IP69K variants)
  • Hygienic cleanroom requirements

Stainless PG9 glands cost 3-5× more than brass but eliminate corrosion-related failures in demanding applications.

IP Rating and Environmental Sealing

PG9 cable glands achieve environmental protection through multiple sealing elements that compress against the cable jacket.

Standard IP Ratings for PG9 Glands

  • IP54: Dust protected, splash water resistant (basic polyamide glands)
  • IP65: Dust tight, jet water resistant (brass glands with flat gasket)
  • IP66: Dust tight, powerful jet resistant (compressed seal design)
  • IP67: Dust tight, temporary immersion resistant (double seal variants)
  • IP68: Dust tight, continuous immersion (pressure-rated seals)
  • IP69K: High-pressure, high-temperature washdown (food industry)

The IP rating depends on both the gland design and proper installation torque. Under-tightening leaves gaps allowing moisture ingress, while over-tightening can damage plastic glands or deform seals.

Sealing Element Configuration

PG9 cable glands employ multiple sealing strategies:

  1. Compression sealing ring: NBR rubber or elastomer ring compressed radially against cable jacket
  2. Multi-hole membrane seal: Pre-punched seal allowing cable insertion with automatic compression
  3. Thread sealing gasket: Flat washer between gland and panel preventing panel-side leakage
  4. Lock nut compression: Internal nut compresses all sealing elements simultaneously

The most common seal material is NBR (Nitrile Butadiene Rubber), offering general-purpose resistance to oils, water, and moderate chemicals across -20°C to +80°C. For extreme conditions, alternative seal materials include EPDM (UV/ozone resistance), Viton (chemical resistance), or silicone (temperature extremes).

PG9 to Metric Thread Conversion

Many modern electrical equipment manufacturers specify metric threads (M12, M16) rather than PG threads, creating conversion challenges for retrofit projects.

PG9 Metric Equivalent Comparison

While no exact metric equivalent exists, M16×1.5 represents the closest metric substitute for PG9:

パラメータPG9M16×1.5Difference
Outer Diameter15.2mm16.0mm+0.8mm
Thread Pitch1.41mm1.5mm+0.09mm
Cable Range4-8mm5-10mmLarger range
Cutout Diameter15.2mm16.0mm+0.8mm

Direct substitution requires panel hole enlargement from 15.2mm to 16.0mm. For existing PG9 holes, reducing bushings or thread adapters enable metric gland installation.

M16 TR 1

PG9 to NPT Conversion

Converting PG9 to NPT (American tapered pipe thread) is more complex due to fundamentally different thread forms:

  • NPT 1/4″ has outer diameter of 13.7mm (smaller than PG9)
  • NPT 3/8″ has outer diameter of 17.1mm (larger than PG9)

No direct NPT equivalent exists for PG9. Conversion requires hybrid glands with PG9 external thread and NPT internal bore, or complete panel re-drilling.

Installation Best Practices for PG9 Cable Glands

Proper PG9 installation ensures IP rating achievement and long-term reliability.

Step-by-Step Installation Process

  1. Panel preparation: Drill or punch 15.2mm diameter hole with smooth, burr-free edges
  2. Component sequence: Thread lock nut, washer, gland body, and seal onto cable in correct order
  3. Cable insertion: Push cable through gland until proper length extends for termination
  4. Seal positioning: Center compression seal around cable with even circumferential contact
  5. Panel mounting: Thread assembled gland into panel hole from exterior side
  6. Lock nut tightening: Hand-tighten lock nut from panel interior until finger-tight
  7. Compression torque: Apply final torque per manufacturer specification (typically 2-5 Nm for PG9)
  8. Visual verification: Confirm seal compression is visible and no gaps exist

Common Installation Errors

Avoid these frequent mistakes when installing PG9 cable glands:

  • Incorrect cable diameter: Using cables outside 4-8mm range prevents proper seal compression
  • Missing seal elements: Omitting washers or seal inserts compromises IP rating
  • Over-tightening: Excessive torque cracks plastic glands or damages seals
  • Panel deformation: Thin panels require backing washers to prevent material crushing
  • Cable damage: Sharp panel edges nick cable jackets, creating moisture entry paths

Applications and Industry Usage

PG9 cable glands serve diverse industrial applications where their mid-range cable capacity aligns with common wire sizes.

Control Panel and Switchgear

Electrical control cabinets frequently specify PG9 for:

  • PLC input/output modules requiring 4-6mm control wire
  • Push-button station connections
  • Indicator light wiring
  • Relay and contactor control circuits

Sensor and Instrumentation

Industrial sensors commonly use PG9 glands for:

  • M12 connector pigtail cables (5-7mm OD)
  • Proximity sensor cables with integral connectors
  • Temperature sensor RTD and thermocouple wiring
  • Pressure transducer signal cables

Machine Tools and Automation

Manufacturing equipment employs PG9 for:

  • Servo motor encoder feedback cables
  • Limit switch wiring on CNC machines
  • Pneumatic valve solenoid connections
  • Human-machine interface (HMI) communication cables

HVAC and Building Systems

Building automation specifies PG9 for:

  • BACnet and Modbus communication networks
  • Variable frequency drive (VFD) control wiring
  • Actuator and damper motor cables
  • Energy meter pulse output connections

Procurement and Specification Guidelines

When specifying PG9 cable glands for projects, include these key parameters in procurement documents:

Minimum specification requirements:

  • Thread type: PG9 per DIN 46320
  • Material: Nickel-plated brass, nylon 66, or stainless steel 316
  • Cable range: 4-8mm (verify against actual cable OD)
  • IP rating: IP65 minimum (or higher as required)
  • Seal material: NBR or specified alternative
  • Temperature rating: Match application environment
  • Quantity and delivery timeline
  • Compliance certifications: CE, UL, CSA as applicable

Request material certifications confirming brass composition, plating thickness, and seal compound specifications. For critical applications, require third-party IP rating testing verification.

Maintenance and Lifespan Considerations

Installed PG9 cable glands require minimal maintenance but benefit from periodic inspection:

  • Quarterly visual checks in harsh environments (outdoor, chemical exposure)
  • Annual inspections in controlled indoor installations
  • Lock nut retorquing if vibration loosening is detected
  • Seal replacement every 5-7 years or when cracking/hardening appears
  • Complete gland replacement if cable modifications are performed

PG9 cable glands are not reusable after removal—compressed seals lose integrity and require complete assembly replacement to restore IP ratings.



External Authority References

関連記事

Cable Gland Installation Guide: 7 Professional Tips for Watertight Sealing

ケーブルグランド設置ガイド防水シーリングのためのプロフェッショナルな7つのヒント

ケーブルグランド設置ガイド:防水シーリングのためのプロフェッショナルな 7 つのヒント 不適切なケーブルグランドの取り付けは、湿気の浸入による産業用機器の故障の 60% を占め、コストのかかるダウンタイムと安全上の危険につながります。サプライヤーの能力を評価する調達マネージャーであれ、IECに準拠した手順を求める設置エンジニアであれ、このガイドは、IP68規格の防水シーリングを達成するための実用的なテクニックを提供します。ケーブルグランドの設置規格を理解する ケーブルグランドの設置は、安全性、信頼性、および環境保護を確保するために国際規格に準拠する必要があります。主な枠組みは、IEC 62444:2010であり、電気設備で使用されるケーブルグランドの構造と性能要件を規定している[web:6]。この規格は、メートルエントリースレッドを持つ完全なケーブルグランドをカバーし、試験 [...] を確立している。

続きを読む
What Is Overhead Crane Remote Control?

天井クレーンの遠隔操作とは?

安全な距離から巨大な産業用クレーンを正確かつ簡単にコントロールできることを想像してみてください。それこそが、オーバーヘッドクレーンの遠隔操作技術がもたらすものです。工場、建設現場、倉庫での重量物の扱い方に革命をもたらし、作業をより安全、迅速、効率的にします。建設現場で鉄骨を持ち上げている場合でも、倉庫でかさばる荷物を移動させている場合でも、このワイヤレス技術により、オペレーターは危険から離れ、遠隔操作で完全な指揮を執ることができます。この記事では、天井クレーンの遠隔操作とは何か、どのように機能するのか、その利点、技術的特徴、一般的なタイプ、主要な安全機能について説明します。また、この技術がどのような場所で、どのように使われているのかについてもご紹介します。

続きを読む
How to Choose the Right Crane Remote Control?

正しいクレーンのリモコンを選ぶには?

正しいクレーンリモコンを選ぶことは、クレーンを使用するあらゆる産業作業にとって重要な決断です。時代遅れの不格好なリモコンでクレーンを操作するのと、安全性、効率性、生産性を高める人間工学に基づいた洗練されたシステムでクレーンを操作するのとの違いを想像してみてください。選び抜かれたリモコンは、作業方法を一変させ、作業をよりスムーズに、より安全に、より費用対効果の高いものにします。建設業、製造業、倉庫業、重量物運搬業などでは、リモコンは精密なハンドリングと作業員の保護に直結するものです。しかし、市場には非常に多くの種類と機能があり、どのように最適なものを選べばよいのでしょうか?このガイドでは、リモコンを選ぶ際の重要な要素をナビゲートします。

続きを読む