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Self-Sealing Locking Nuts

APM SEELNUT® High Pressure Self-Sealing Locking Nuts specifications & selection chart for    self-sealing nuts O-Ring materials & characteristics    selection chart

The APM SEELNUT® is the original self-sealing nut designed and patented by APM. Our self-sealing locking nuts are designed for use on all types of adjusting screws, threaded studs, and machine bolts in applications where leakage may occur due to extreme pressures.

Installed like an ordinary nut, our self-sealing locking nuts form a high-pressure seal along the thread section and contact surface when torqued. Their single-piece design eliminates the need for gaskets, sealing compounds and surface preparations. Fully-adjustable and reusable, these self-sealing locking nuts resist vibration, provide metal-to-metal contact, and seal under vacuum or internal/external high pressure.

Unlike some imitators, the APM SEELNUT® uses a molded-in, elastomeric insert, instead of an O-Ring.  This specially designed insert features threads on its' inside diameter.  The purpose of this insert is to replace the threads that would normally be removed for positioning of the seal. This design accomplishes three goals:

1. Maximum threads permit maximum torque values.  
2. Unlike an O-Ring (which has no threads), the insert’s threaded surface will mate perfectly with the  fastener’s threads (where the real sealing takes place) and not bulge out above the top of the nut preventing  desired metal surface- to-surface contact.
3. Because there is no O-Ring, there is no degradation, therefore the SEELNUT can be reused with confidence. 

This critical design insert  innovation gives SEELNUT the capacity to reliably seal to 6,000psi/vacuum (internal/ external) at temperatures from -160°F  to +500°F (-106° C to 260° C).   A feat that could not be accomplished by a conventional O-Ring.

APM self-sealing locking nuts are available in all standard thread sizes, and the integral seal can be formulated for compatibility with most gases or liquids. SEELNUTs can also be supplied with optional self-locking pellets.

SEELNUT Self-Sealing Locking Nuts
Features and Benefits:

• Positive sealing under vacuum or pressure to 6,000psi
• Install like a conventional nut
• Reusable & compatible with all surface finishes
• 360° metal-to-metal contact assures fastening integrity
• Wide temperature range
• Optional O-ring seal materials - silicone rubber, BUNA-N (see selection chart)
• Uniform, high-strength design
• UL & CSA Recognized
• UL Tested
• Optional threadlocking add-ons
• Jam styles available
• Made in USA

 

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view threadlocking enhancements for self-sealing locking nuts

To order self-sealing locking nuts
contact your local APM authorized distributor
or call APM Hexseal at 800.498.9034

 

The APM line of self-sealing fasteners includes self-sealing screws, self-sealing locking nuts, self-sealing locking bolts, self-sealing rivets, and self-sealing washers all designed to seal in/out air, water, lubricants and other liquid or gaseous contaminants.