Rotary switches are unique in that they operate with a twisting motion as opposed to a push or press motion.

Rotary switches are unique in that they operate with a twisting motion, as opposed to a push or press motion. This makes them particularly difficult to seal, especially in high-impact or heavy-duty operations. Rubber and elastomer rotary boots create a seal around a rotary switch while still allowing free movement of the central rotary shaft.

The central shaft of a rotary device must be free to rotate, which can make sealing a rotary device more complicated to accomplish. Since a full-coverage boot does not work for a rotary device, APM Hexseal developed a specialized open boot, molded from silicone to a threaded mounting nut. Once correctly mounted, it seals around the rotating shaft as well as to the mounting panel. These boots are specifically designed to withstand the friction created by the shaft rotation without restricting the actuation motion.

Improper sealing results in contamination from dust, dirt, and unwanted fluids. This contamination can lead to irregular switch function and eventual complete system failure. Rotary boots mitigate these risks, making them a critical component in any rotary switch array. Used properly, rotary switch boots help to keep the area around the switch clear of unwanted debris and contaminants while ensuring full rotary actuation. 

The Anatomy of Rotary Boots

Rotary boots are complicated to design, as they must provide a complete seal without restricting the rotating motion of the central shaft. Unlike standard push and pull switches, rotary switches cannot be sealed using a typical full-coverage boot. 

To address this issue, APM Hexseal’s rotary boot features an open design that seals the boot directly to a threaded mounting nut. Once mounted, the silicone boot creates a complete seal around the rotating shaft and mounting panel. Manufactured from highly durable and corrosion-resistant silicone, APM Hexseal’s rotary boots can withstand the high friction generated by the rotation of the central shaft, allowing the shaft to rotate freely while ensuring a complete seal. 

Installation

At APM Hexseal, we understand the need for easy installation in busy operating environments. Our rotary boots are easy to install and offer long-lasting protection. To install, simply remove the base of the switch from the dial and slip the boot over the base. The sealed base can then be situated over the mounting hole and the switch dial can be replaced on the spindle. 

Once the switch dial has been reattached, your rotary switch is fully sealed, and the dial can still rotate freely. With installation complete, you’ve enhanced the service life of your switch while lessening long-term maintenance and replacement requirements.

Materials

APM Hexseal is pleased to manufacture sealing and fastening hardware using the highest quality materials. Our Standard Threaded Rotary Boots use a nickel-plated brass mounting nut to attach a silicone boot that conforms to A-A-59588, Class 3A, and GR50 standards. The silicone-based elastomer seals withstand temperatures between -103°F to 400°F (-75°C to 204°C), and are resistant to splash, salt spray, sunlight, ozone, weather, and a variety of other extreme conditions. 

Our rotary boots feature a standard shelf life of more than 25 years. We can manufacture them in a variety of colors to suit the needs of virtually any application. 

Applications

The durability and versatility of rotary boots from APM Hexseal make them an ideal choice for a wide range of high-performance environments, including: 

  • Heavy industrial equipment
  • Marine equipment
  • Medical devices and equipment
  • Energy production equipment
  • Transportation equipment
  • Military equipment

Whatever your application’s needs, APM Hexseal has the perfect sealing and fastening hardware to keep your rotary equipment protected in even the most extreme environments. 

About APM Hexseal

APM Hexseal is a leading provider of innovative sealing and fastening solutions for a wide range of industries. With more than 50 years of experience, we have developed our own custom manufacturing processes that set our sealing solutions apart from the rest. Our proprietary selection of state-of-the-art products includes rotary boots, Seelskrews, Seelbolts, and Seelnuts, among many others. 

To see how our sealing solutions can improve your operations, Ask the Experts at APM Hexseal today!

Ever Better. 

Rotary Boots
Rotary Boots
Material Specifications

For APM Hexseal® Standard Threaded Rotary Boots

Mounting Nut:
Brass, Nickel Plated
Elastomer:
Silicone conforms to A-A-59588, Class 3A, GR50 †, Gray ‡
Temperature Range:
-103° F to +400° F ( -75° C to +204° C)
Resistant to:
Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
Shelf Life:
Excess of 25 years.
APM Hexseal
Part #
Military
Part #
Thread Size Shaft Size (A) Height (B) Hex Size (C) System of
Measurement
N9030x1/4 M5423/09-02 3/8-32 UNEF-2B 0.250" 6.35mm 0.219" 5.56mm 0.500" 12.70mm Imperial
N9040x1/8 M5423/09-03 1/4-32 UNEF-2B 0.125" 3.18mm 0.219" 5.56mm 0.375" 9.53mm Imperial
N9042x1/8 - 1/4-28 UNF-2B 0.125" 3.18mm 0.219" 5.56mm 0.375" 9.53mm Imperial
N9060x1/4 M5423/09-04 15/32-32 UNS-2B 0.250" 6.35mm 0.219" 5.56mm 0.625" 15.88mm Imperial
1332/39 - M7x.75 6H 0.196" 5.00mm 0.200" 5.50mm 0.500" 12.70mm Metric
1332/45 - M10x1 6H 0.236" 6.00mm 0.236" 5.90mm 0.500" 12.70mm Metric
1332/46 - M10x.75 6H 0.236" 6.00mm 0.236" 5.90mm 0.500" 12.70mm Metric
C1332/41 - M9x.75 6H 0.250" 6.35mm 0.219" 5.56mm 0.500" 12.70mm Metric
Rotary Boots
Rotary Boots
Material Specifications

For APM Hexseal® Standard Threaded Rotary Boots

Mounting Nut:
Brass, Nickel Plated
Elastomer:
Silicone conforms to A-A-59588, Class 3A, GR50 †, Gray ‡
Temperature Range:
-103° F to +400° F ( -75° C to +204° C)
Resistant to:
Splash, salt spray, sunlight, ozone, weather, fungus, dust, and most acids and lubricating oils.
Shelf Life:
Excess of 25 years.
APM Hexseal
Part #
Military
Part #
Thread Size Shaft Size (A) Height (B) Hex Size (C) System of
Measurement
N9030x1/4 M5423/09-02 3/8-32 UNEF-2B 0.250" 6.35mm 0.219" 5.56mm 0.500" 12.70mm Imperial
N9040x1/8 M5423/09-03 1/4-32 UNEF-2B 0.125" 3.18mm 0.219" 5.56mm 0.375" 9.53mm Imperial
N9042x1/8 - 1/4-28 UNF-2B 0.125" 3.18mm 0.219" 5.56mm 0.375" 9.53mm Imperial
N9060x1/4 M5423/09-04 15/32-32 UNS-2B 0.250" 6.35mm 0.219" 5.56mm 0.625" 15.88mm Imperial
1332/39 - M7x.75 6H 0.196" 5.00mm 0.200" 5.50mm 0.500" 12.70mm Metric
1332/45 - M10x1 6H 0.236" 6.00mm 0.236" 5.90mm 0.500" 12.70mm Metric
1332/46 - M10x.75 6H 0.236" 6.00mm 0.236" 5.90mm 0.500" 12.70mm Metric
C1332/41 - M9x.75 6H 0.250" 6.35mm 0.219" 5.56mm 0.500" 12.70mm Metric