Leading Manufacturer of Safety Interlock Switches and Machine Guard Safety Switch Devices for Automation and Process Safety

Trapped Key Bolt Interlock with Dual Key (M-BD-11)

The M-BD-11 Trapped Key Interlock operates by using a locking bolt mechanism, which is extended when in the lock position. Inserting and turning the appropriate key allows the secondary key to be released, retracting the bolt and allowing access to the hazardous area. The second key (often referred to as the personnel key) should be taken inside the hazardous area to reduce the likelihood of an inadvertent start-up.


  • Material: Mirror Polished Die-Cast Metal
  • Holding Force: F1Max 5000N
Part Number Part Description
M-BD-11 Bolt Interlock Dual Key – 1 Key Trapped 1 Key Free – Bolt Retracted – Die Cast
M-BD-20 Bolt Interlock Dual Key – 2 Key Trapped 0 Key Free – Bolt Retracted – Die Cast

Important Note
It is important that when the bolt is retracted, it is held captive until the guard is closed. If you can extend the bolt whilst the guard is open, you are at risk of serious harm.
Key sold separately

Technical Data
MaterialDie-Cast Metal
Operating Temperature-25 ... +60 °C
Holding Force5000N. (F1max.) 3846N. (Fzh)
Mechanical Life (B10d) 1,000,000 cycles