Cover it. Seal it. Protect it.

APM Hexseal has been designing self-sealing boots and fasteners for more than 70 years. We specialize in developing and manufacturing sealing solutions that offer superior performance in even the harshest environments.


Switch Boots

Any unsealed electrical devices mounted to a control panel or a piece of Electrical equipment can fall victim to the impacts of hostile environmental factors if not properly protected. APM Hexseal’s sealing boots are designed to protect the vulnerable areas of a device and create a seal against the mounting panel, providing strong protection for the device itself, and for the overall function of the system.
  • Full Toggle Boots
  • ½ Toggle Boots
  • Push Button Boots
  • Rotary Boots
  • Armored and RFI Boots
  • Bushings
  • Many boots are UL/ULS recognized

Circuit Breaker/Rocker Boots

Circuit breakers perform a very valuable role in all sorts of control systems, protecting equipment from short circuits and electrical overloads. APM Hexseal’s lever actuated circuit breaker boots are designed to protect these critical devices, extending breaker life-spans and in turn helping to ensure long-term security of the system as a whole.

  • Circuit Breaker Boots- Front panel mounting
  • Circuit Breaker Boots- Back of panel mounting
  • Rocker Boots
  • Many boots are UL/ULS recognized

Self-Sealing Fasteners

APM Hexseal holds the notable distinction of having designed and patented the very first self-sealing fasteners, which became our trademarked Seelskrews® and Seelbolts®. In addition to fastening, our self-sealing screws and bolts offer a reliable and reusable seal, preventing (or containing!) contamination from dust, air, water, lubricants and other liquid or gaseous substances. 

  • Screws 
  • Bolts
  • Available in Metric and Imperial sizes
  • Phillps, Slotted and other drive styles
  • 18-8 Stainless
  • Variety or elastomer options
  • Most screws and bolts are UL/ULS recognized

Self-Sealing Nuts

APM Hexseal’s Seelnuts® are made from high quality rubber, molded into a specially shaped cavity in the nut itself. With threads molded directly into the rubber, these self-sealing nuts form a positive seal along the threaded section of the Seelnut, as well as with the contact surface, removing the need for gaskets, sealing

compounds or extra surface preparation. Seelnuts install just like conventional nuts, and are designed for use with ordinary screws, bolts and studs, making them a quick and easy sealing option for all sorts of applications, especially where there is a need to withstand high internal or external pressures. Seelnuts are also reusable, meaning that they can be easily removed and reapplied, reestablishing the same reliable seal when torqued.

  • Standard Nuts
  • Jam Nuts
  • Metric and Imperial sizes
  • Low Carbon Steel/Zink plating
  • 18-8 Stainless Steel
  • Variety of elastomer choices
  • Most nuts are UL/ULC rated

Sealing Washers

APM Hexseal’s Seeloc® Washers consist of molded silicone rubber bonded to specially formed stainless steel washers. Designed to be used in conjunction with conventional screws, bolts or studs, Seeloc Washers are a simple sealing solution that is ideal for all sorts of applications, especially where spray, vapors or wash-downs are present, or where there is concern of contamination from dust, oils or salt build-up. The silicone contact surface features a continuous ridge which, upon compression, creates a 360° sealing barrier around the periphery of the washer face. The silicone rubber also forms a seal under the head of the associated fastener and makes full vertical contact with the threads/shank, making for a complete, high-pressure seal unlike any other.

  • Metric and Imperial sizes
  • Standard and Heavy Duty
  • 18-8 Stainless Steel
  • Variety of elastomer choices
  • Most washers are UL/ULS recognized.

Custom Assemblies

Since 1947, APM Hexseal has been 100% focused on the development and production of internal and external sealing solutions for electrical and electronic applications, from relatively simple designs to complex geometric configurations, many requiring bonding to metal components. By drawing upon our experience with precision transfer and compression molding using a wide range of elastomers, rubber-to-metal bonding and coating treatments, we developed an effective and efficient process that takes a custom seal request from concept to production. The resulting solutions are rugged, reliable, and completely tailored to customer specifications. Read on to find out how our custom process guarantees the delivery of a tight and long-lasting seal.