One of our earliest innovations is Seelnuts®, which offers reliable performance in temperatures between 103 °F and 400 °F. The self-sealing hardware products are beneficial in a wide variety of applications, easy to install, and compatible with standard bolts, screws, and studs.
APM Hexseal’s Seelnuts are also reusable, meaning that they can be easily removed and reapplied, reestablishing the same reliable seal when torqued.
Our Seelnuts are available in all standard thread sizes as well as a variety of different elastomers to suit your application needs. Seelnuts can also be supplied with self-locking pellets for applications where excessive vibration is an issue.
For information on maximum torque values for Seelnuts® please see our table of Torque Values for Self-Sealing Hardware.
- IMPERIAL SEELNUTS® - Standard Nut Style
- IMPERIAL SEELNUTS® - Jam Nut Style
- METRIC* SEELNUTS® - Standard Nut Style
IMPERIAL SEELNUTS® - Standard Nut Style
MATERIAL SPECIFICATIONS
For APM Hexseal® Standard Seelnuts®
- Nut Material:
- Low Carbon Steel with Zinc-Chromate Plating †
- Threads:
- Imperial— Class 2B ‡; Metric— Class 6H
- Elastomer:
- Silicone conforms to A-A-59588, Class 3A, GR60, Red ◊
- Temperature Range:
- -103° F to +400° F ( -75° C to +204° C)
- Pressure Range:
- Up to 20,000 psig internal and external (subject to clearance hole dimensions).
- Resistant to:
- Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
- Shelf Life:
- Excess of 25 years.
† Standard Jam Nut material is Brass with Nickel Plating.
‡ Standard for stock nuts.
◊ Alternative elastomers are available by special order. Please consult our Molded Elastomer Options for details.
| Thread Size | Height of Sealing Rib (R) | Distance Between Flats (C) | Max. Head Height (D) |
|---|---|---|---|
| 6-32 UNC-2B | 1/64" | 5/16" | 9/64" |
| 8-32 UNC-2B | 1/64" | 3/8" | 5/32" |
| 10-32 UNF-2B | 1/64" | 3/8" | 5/32" |
| 10-24 UNC-2B | 1/64" | 3/8" | 5/32" |
| 1/4-20 UNC-2B | 1/64" | 7/16" | 7/32" |
| 1/4-28 UNF-2B | 1/64" | 7/16" | 7/32" |
| 5/16-18 UNC-2B | 1/64" | 1/2" | 17/64" |
| 5/16-24 UNF-2B | 1/64" | 1/2" | 17/64" |
| 3/8-16 UNC-2B | 1/64" | 9/16" | 21/64" |
| 3/8-24 UNF-2B | 1/64" | 9/16" | 21/64" |
| 7/16-20 UNF-2B | 1/32" | 11/16" | 3/8" |
| 1/2-13 UNC-2B | 1/32" | 3/4" | 27/64" |
| 1/2-20 UNF-2B | 1/32" | 3/4" | 27/64" |
| 5/8-18 UNF-2B | 1/32" | 15/16" | 35/64" |
For a full list of part numbers, please contact APM Hexseal.
IMPERIAL SEELNUTS® - Jam Nut Style
MATERIAL SPECIFICATIONS
For APM Hexseal® Standard Seelnuts®
- Nut Material:
- Low Carbon Steel with Zinc-Chromate Plating †
- Threads:
- Imperial— Class 2B ‡; Metric— Class 6H
- Elastomer:
- Silicone conforms to A-A-59588, Class 3A, GR60, Red ◊
- Temperature Range:
- -103° F to +400° F ( -75° C to +204° C)
- Pressure Range:
- Up to 20,000 psig internal and external (subject to clearance hole dimensions).
- Resistant to:
- Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
- Shelf Life:
- Excess of 25 years.
† Standard Jam Nut material is Brass with Nickel Plating.
‡ Standard for stock nuts.
◊ Alternative elastomers are available by special order. Please consult our Molded Elastomer Options for details.
| Thread Size | Height of Sealing Rib (R) | Distance Between Flats (C) | Max. Head Height (D) |
|---|---|---|---|
| 6-32 UNC-2B | 1/64" | 1/2" | 7/32" |
| 8-32 UNC-2B | 1/64" | 1/2" | 7/32" |
| 10-32 UNF-2B | 1/64" | 1/2" | 7/32" |
| 10-24 UNC-2B | 1/64" | 1/2" | 7/32" |
| 1/4-20 UNC-2B | 1/64" | 5/8" | 7/32" |
| 1/4-28 UNF-2B | 1/64" | 5/8" | 7/32" |
| 5/16-18 UNC-2B | 1/64" | 5/8" | 7/32" |
| 5/16-24 UNF-2B † | 1/64" | 5/8" | 7/32" |
| 3/8-16 UNC-2B | 1/64" | 5/8" | 7/32" |
| 3/8-24 UNF-2B | 1/64" | 5/8" | 7/32" |
| 1/2-13 UNC-2B | 1/32" | 3/4" | 7/32" |
| 1/2-20 UNF-2B | 1/32" | 3/4" | 7/32" |
For a full list of part numbers, please contact APM Hexseal.
† The Jam Nut material used for this thread size is Low Carbon Steel with Zinc-Chromate plating.
METRIC* SEELNUTS® - Standard Nut Style
MATERIAL SPECIFICATIONS
For APM Hexseal® Standard Seelnuts®
- Nut Material:
- Low Carbon Steel with Zinc-Chromate Plating †
- Threads:
- Imperial— Class 2B ‡; Metric— Class 6H
- Elastomer:
- Silicone conforms to A-A-59588, Class 3A, GR60, Red ◊
- Temperature Range:
- -103° F to +400° F ( -75° C to +204° C)
- Pressure Range:
- Up to 20,000 psig internal and external (subject to clearance hole dimensions).
- Resistant to:
- Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
- Shelf Life:
- Excess of 25 years.
† Standard Jam Nut material is Brass with Nickel Plating.
‡ Standard for stock nuts.
◊ Alternative elastomers are available by special order. Please consult our Molded Elastomer Options for details.
| Thread Size | Height of Sealing Rib (R) | Distance Between Flats (C) | Max. Head Height (D) |
|---|---|---|---|
| M3 x 0.5 | 0.2mm | 5.5mm | 2.2mm |
| M4 x 0.7 | 0.3mm | 7.0mm | 3.0mm |
| M5 x 0.8 | 0.4mm | 8.0mm | 3.8mm |
| M6 x 1 | 0.5mm | 10.0mm | 4.8mm |
| M8 x 1.25 | 0.6mm | 13.0mm | 6.3mm |
| M10 x 1.5 | 0.6mm | 17.0mm | 7.8mm |
| M12 x 1.75 | 0.8mm | 19.0mm | 9.3mm |
| M14 x 2 | 0.1mm | 22.0mm | 10.8mm |
For a full list of part numbers, please contact APM Hexseal.
* APM Hexseal’s standard material for metric nuts is Stainless-Steel.
IMPERIAL SEELNUTS® - Standard Nut Style
MATERIAL SPECIFICATIONS
For APM Hexseal® Standard Seelnuts®
- Nut Material:
- Low Carbon Steel with Zinc-Chromate Plating †
- Threads:
- Imperial— Class 2B ‡; Metric— Class 6H
- Elastomer:
- Silicone conforms to A-A-59588, Class 3A, GR60, Red ◊
- Temperature Range:
- -103° F to +400° F ( -75° C to +204° C)
- Pressure Range:
- Up to 20,000 psig internal and external (subject to clearance hole dimensions).
- Resistant to:
- Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
- Shelf Life:
- Excess of 25 years.
† Standard Jam Nut material is Brass with Nickel Plating.
‡ Standard for stock nuts.
◊ Alternative elastomers are available by special order. Please consult our Molded Elastomer Options for details.
| Thread Size | Height of Sealing Rib (R) | Distance Between Flats (C) | Max. Head Height (D) |
|---|---|---|---|
| 6-32 UNC-2B | 1/64" | 5/16" | 9/64" |
| 8-32 UNC-2B | 1/64" | 3/8" | 5/32" |
| 10-32 UNF-2B | 1/64" | 3/8" | 5/32" |
| 10-24 UNC-2B | 1/64" | 3/8" | 5/32" |
| 1/4-20 UNC-2B | 1/64" | 7/16" | 7/32" |
| 1/4-28 UNF-2B | 1/64" | 7/16" | 7/32" |
| 5/16-18 UNC-2B | 1/64" | 1/2" | 17/64" |
| 5/16-24 UNF-2B | 1/64" | 1/2" | 17/64" |
| 3/8-16 UNC-2B | 1/64" | 9/16" | 21/64" |
| 3/8-24 UNF-2B | 1/64" | 9/16" | 21/64" |
| 7/16-20 UNF-2B | 1/32" | 11/16" | 3/8" |
| 1/2-13 UNC-2B | 1/32" | 3/4" | 27/64" |
| 1/2-20 UNF-2B | 1/32" | 3/4" | 27/64" |
| 5/8-18 UNF-2B | 1/32" | 15/16" | 35/64" |
For a full list of part numbers, please contact APM Hexseal.
IMPERIAL SEELNUTS® - Jam Nut Style
MATERIAL SPECIFICATIONS
For APM Hexseal® Standard Seelnuts®
- Nut Material:
- Low Carbon Steel with Zinc-Chromate Plating †
- Threads:
- Imperial— Class 2B ‡; Metric— Class 6H
- Elastomer:
- Silicone conforms to A-A-59588, Class 3A, GR60, Red ◊
- Temperature Range:
- -103° F to +400° F ( -75° C to +204° C)
- Pressure Range:
- Up to 20,000 psig internal and external (subject to clearance hole dimensions).
- Resistant to:
- Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
- Shelf Life:
- Excess of 25 years.
† Standard Jam Nut material is Brass with Nickel Plating.
‡ Standard for stock nuts.
◊ Alternative elastomers are available by special order. Please consult our Molded Elastomer Options for details.
| Thread Size | Height of Sealing Rib (R) | Distance Between Flats (C) | Max. Head Height (D) |
|---|---|---|---|
| 6-32 UNC-2B | 1/64" | 1/2" | 7/32" |
| 8-32 UNC-2B | 1/64" | 1/2" | 7/32" |
| 10-32 UNF-2B | 1/64" | 1/2" | 7/32" |
| 10-24 UNC-2B | 1/64" | 1/2" | 7/32" |
| 1/4-20 UNC-2B | 1/64" | 5/8" | 7/32" |
| 1/4-28 UNF-2B | 1/64" | 5/8" | 7/32" |
| 5/16-18 UNC-2B | 1/64" | 5/8" | 7/32" |
| 5/16-24 UNF-2B † | 1/64" | 5/8" | 7/32" |
| 3/8-16 UNC-2B | 1/64" | 5/8" | 7/32" |
| 3/8-24 UNF-2B | 1/64" | 5/8" | 7/32" |
| 1/2-13 UNC-2B | 1/32" | 3/4" | 7/32" |
| 1/2-20 UNF-2B | 1/32" | 3/4" | 7/32" |
For a full list of part numbers, please contact APM Hexseal.
† The Jam Nut material used for this thread size is Low Carbon Steel with Zinc-Chromate plating.
METRIC* SEELNUTS® - Standard Nut Style
MATERIAL SPECIFICATIONS
For APM Hexseal® Standard Seelnuts®
- Nut Material:
- Low Carbon Steel with Zinc-Chromate Plating †
- Threads:
- Imperial— Class 2B ‡; Metric— Class 6H
- Elastomer:
- Silicone conforms to A-A-59588, Class 3A, GR60, Red ◊
- Temperature Range:
- -103° F to +400° F ( -75° C to +204° C)
- Pressure Range:
- Up to 20,000 psig internal and external (subject to clearance hole dimensions).
- Resistant to:
- Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
- Shelf Life:
- Excess of 25 years.
† Standard Jam Nut material is Brass with Nickel Plating.
‡ Standard for stock nuts.
◊ Alternative elastomers are available by special order. Please consult our Molded Elastomer Options for details.
| Thread Size | Height of Sealing Rib (R) | Distance Between Flats (C) | Max. Head Height (D) |
|---|---|---|---|
| M3 x 0.5 | 0.2mm | 5.5mm | 2.2mm |
| M4 x 0.7 | 0.3mm | 7.0mm | 3.0mm |
| M5 x 0.8 | 0.4mm | 8.0mm | 3.8mm |
| M6 x 1 | 0.5mm | 10.0mm | 4.8mm |
| M8 x 1.25 | 0.6mm | 13.0mm | 6.3mm |
| M10 x 1.5 | 0.6mm | 17.0mm | 7.8mm |
| M12 x 1.75 | 0.8mm | 19.0mm | 9.3mm |
| M14 x 2 | 0.1mm | 22.0mm | 10.8mm |
For a full list of part numbers, please contact APM Hexseal.
* APM Hexseal’s standard material for metric nuts is Stainless-Steel.
