Rotary switches control multiple circuits or settings through a single rotating shaft. When those switches are mounted through a panel opening, the interface between the shaft, mounting point, and panel can become a path for moisture, dust, oil, and other contaminants. APM Hexseal rotary boots are single-piece silicone rubber covers designed to seal that vulnerable interface and help protect switch performance in demanding environments.

APM Hexseal has specialized in developing sealing solutions for electrical and electronic components since 1947. Our rotary boots represent decades of engineering focused on preventing environmental intrusion at switch mounting points.

The sections below explain how a rotary boot protects the switch interface, where rotary switch boots are commonly used, and what specifications are available for APM Hexseal models.

Rotary Boots for Sealing and Protecting Rotary Switches

Any panel opening where a rotary switch is mounted creates a potential entry point for contaminants. Without proper sealing, water, oil, dust, sand, chemicals, and debris can reach the switch interface, interfering with operation. Rotary switch boots are designed to create a seal between the switch and the mounting panel, helping protect the switch from exposure in harsh operating conditions.

Advantages of Rotary Boots

APM Hexseal rotary boots are designed to protect the switch interface without limiting switch function. Key performance features include:

  • Complete Sealing Protection. Seals the shaft and panel interface to help block moisture and contaminants.
  • Integrated Mounting Solution. Standard threaded designs integrate with the switch mounting interface and replace the panel mounting nut.
  • Operational Compatibility. Maintains switch movement without interfering with operation.
  • Vibration Resistance. Supports use in vibration-prone environments.
  • Adaptable Sizing. Available in multiple sizes, with thread adapters for additional fitment options.
  • Military-Grade Standards. Select models correspond to military part numbers; confirm part-specific requirements for MIL-Spec applications.

Applications for Rotary Boots

Rotary boots are used in applications where exposed panel-mounted switches need protection from contamination and environmental stress. Common use cases include:

They are commonly used on switches involved in speed control, input selection, and power management, where contamination at the switch interface can lead to unreliable operation.

Rotary Boots
Rotary Boots

Material Specifications

APM Hexseal® Standard Threaded Rotary Boots are available in both imperial and metric sizes. Standard material and performance specifications include:

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

APM Hexseal® Standard Threaded Rotary Boots are available in both imperial and metric sizes. Standard material and performance specifications include:

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

Why Choose APM Hexseal for Rotary Boots

APM Hexseal has specialized in sealing solutions for electrical and electronic applications since 1947. That experience includes both standard products and custom configurations, including designs that require rubber-to-metal bonding and close control over material and dimensional performance.

Our in-house manufacturing capabilities include mold presses, cobots, a full machine shop, X-ray inspection equipment, and rubber mills. Keeping these capabilities under one roof supports quality control, product consistency, and application-specific development when standard rotary switch boots are not the right fit.

Contact us to discuss your rotary switch boots sealing requirements or request a quote for your specific application.