Description
The Mid-Depth M8 Gland Cable Penetrator is a compact sealing solution designed for underwater cable pass-through at depths up to 300 meters (984 feet). It uses a pressure-rated compression gland system to provide a watertight seal where cables must pass through aluminum end caps or enclosure walls. The M8 thread format offers a space-efficient option for compact subsea devices, while maintaining a robust sealing interface.
This penetrator is precision-fitted for use with a single cable type: the 3-Core (20AWG) Underwater Cable. The combination is carefully matched to deliver optimal compression sealing under moderate pressure. While not intended for other Blu-Sub cable types, the M8 penetrator may be compatible with certain third-party cables of similar diameter. Please refer to specifications and contact us for assistance with sizing or custom options.
Seal Construction Concept:
Unlike larger penetrator models that use multiple sealing rings and split compression stacks, the M8 Gland Cable Penetrator employs a simplified sealing mechanism suited for mid-depth pressures. The sealing system relies on precise interference between the penetrator body, compression plug, and a single elastomeric sealing ring. When the locking cap is torqued, it axially compresses the seal around the cable sheath, forcing radial expansion against both the inner wall of the penetrator and the outer jacket of the cable.
As water pressure increases during submersion, the cable sheath compresses slightly inward, which further enhances the seal by forcing the elastomer to expand and wedge more tightly into the inner beveled geometry of the penetrator. This self-reinforcing design ensures increasing sealing force under pressure, while maintaining flexibility to accommodate cable tolerances and surface irregularities.
For simplicity, the Mid-Depth M8 design does not use sleeve or gap rings found in larger models, relying instead on its single-ring compression system to achieve proper sealing.
Each M8 Gland Cable Penetrator is pre-matched to its supported cable size and includes all required sealing components. The simple and compact design reduces part count while maintaining high sealing performance for underwater applications.
Compatible With: Blu-Sub Deep-Sea Cables
Sold Separately
M8 Gland Cable Penetrators are precision-fitted to seal around a single cable type: the 3-Core (20AWG) Underwater Cable. This combination provides a reliable watertight seal using a compression gland system. While not intended for other Blu-Sub cables, these penetrators may be used with select third-party cables of similar dimensions. Refer to specifications or contact us for compatibility support.
Alternative Cable Penetrator Options
Blu-Sub offers several cable penetrator options tailored for different enclosure sizes, sealing methods, and underwater depth requirements:
Deep-Sea Cable Penetrators – Epoxy-sealed bulkhead design for permanent installations in high-pressure environments. Depth Rating: Up to 1,000 m / 3,281 ft
Deep-Sea M10 Gland Cable Penetrators – Threaded penetrators with compression glands, ideal for deepwater modular enclosures and strain-relief cable management. Depth Rating: Up to 1,000 m / 3,281 ft
Low-Depth M10 Gland Cable Penetrators – An economical option for shallow water or low-pressure use. Depth Rating: Up to 100 m / 328 ft
Compatible With: Blu-Sub Enclosures & Mounting Interfaces
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Subsea Aluminum End-Cap
Available in models with M8 holes pre-drilled or blank positions that can be user-drilled to accept M8 gland cable penetrators. Installs with a rear locking nut for watertight sealing.
Subsea Acrylic End-Cap
Transparent, cost-effective end-cap option available in versions with M8 thru-holes, or blank variants that can be user-drilled to accept M8 gland cable penetrators. Installs using a rear locking nut. Intended for shallow-water use with lower depth ratings.
Subsea Polymer Flange & End-Cap
Easily user-drilled to accept M8 gland penetrators. Ideal for modular shallow or mid-depth enclosures where custom hole sizing is required.
Subsea Watertight Enclosure Box
Pre-drilled with 20 unthreaded M10 ports, which are not compatible with M8 gland penetrators. A separate M8 hole must be drilled for proper installation.
Compatible Installation Tool
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This product can be installed using the Universal M8/M10 Installation Wrench, a dedicated tool designed for Blu-Sub M8 and M10 bulkhead-style components such as penetrators, switches, sensors, and connector-style hardware.
Its compact dual-end design allows installation in tight or closely spaced layouts, while cable-pass slots allow the wrench to slide over pre-attached cables, enabling installation or servicing without disconnecting wiring.
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Technical Specifications
| Item | M8 Gland Penetrator |
|---|---|
| Main Material | Aluminum |
| Compatible Cable | Deep-Sea Cable 3×20AWG (BS-SSC-3CORE-BLK-20A1) |
| Waterproofing Depth | 300 meters |
| Weight | 7.8g |
| Recommended Bulkhead Hole (A) | Ø8.1±0.1 / Threaded |
| Hatch Cover Thickness (B) | 14 |
| Surface Range (C) | 17 |
Product: Mid-Depth M8 Gland Cable Penetrators
Description: M8 gland-style cable penetrators provide a compact sealing solution for mid-depth underwater enclosures. These components ensure a watertight pass-through for small-diameter Deep-Sea Cables.
Installation Guide:
- Cut the cable to the appropriate length. Strip the sheath and core filler at the enclosure end, ensuring the sheath has a clean, flat cut.
- Clean the cable's outer jacket and all penetrator components with alcohol and a lint-free cloth.
- Thread the penetrator parts onto the cable in the correct order. Press the cable inward and hand-tighten the locking cap.
- Use a wrench and vise (or a non-marring wrench tool) to tighten the locking cap and body until it is fully seated. Avoid overtightening.
Notes:
- The M8 design does not include sleeve or gap rings; sealing is achieved by the compression of a single elastomeric ring.
- The cable sheath must be cut flat to ensure proper sealing contact.
- All components—including cable jackets, seals, and the inside of the penetrator—must be cleaned thoroughly with alcohol to remove dust, oil, and debris.
- Maintain inward pressure on the cable during final tightening to keep the sealing ring evenly compressed around the sheath.
Can the sealing part be disassembled and assembled repeatedly?
It is not recommended to dismantle the sealing part repeatedly. If necessary, avoid doing it more than twice, and do not reuse the same compression area of the cable. Trim the cable sheath before reassembly.
How is the waterproof depth guaranteed?
The gland's dimensional structure is engineered to meet sealing requirements. When the locking cap is screwed to its specified position, it compresses the seal to ensure waterproofing to the rated depth.
What are the advantages over glue-filled cable penetrators or underwater connectors?
Unlike glue-filled penetrators, this design allows the cable to be bent or pulled without risk, requires no curing time, and can be disassembled if needed. It offers a non-pluggable but fixed outlet connection that is more convenient and reliable for certain applications.
Is the water depth data a theoretical value?
The depth rating is based on actual small-batch pressure testing. For example, the 300 m depth rating has been tested at 400 m for over a week under pressure.
Can other brands of cables be used?
Compatibility with non-standard cables should be verified through pressure testing, as the rated depth is based on testing with known cable specifications.
Can the scratch-proof gland penetrator be used with this product?
No, the scratch-proof gland penetrator is not compatible with this product due to different sizing and mechanical interface.
3D Model Viewer
Note: The 3D model shown above is for reference purposes only. It may include components, accessories, or alternate sizes not included with the product. For simplicity, only a single representative size is typically displayed when multiple versions exist. Please refer to the product Shipping Guide for detailed information on included contents and size-specific differences.
Applicable Blu-Guide Articles
