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.
