DOLD SAFEMASTER STS M11BM/K Trapped-Key Guard Lock Review: Specs, Price and Applications
STS-M11BM/K is a mechanical SAFEMASTER STS guard-lock configuration with a separate actuator and forced key removal. In the supplied sequence, inserting the first key permits removal of the second key and then the actuator. This creates a defined mechanical access sequence; its behavior must be distinguished from electrically monitored STS switches and from separate power-interlocking assemblies.
Quick Verdict
Consider this configuration when a mechanical key exchange can enforce the required access order. Confirm the exact unit, keys and actuator against DOLD’s current drawings before purchasing. Mechanical key transfer can preserve authorization without control wiring at each access, but it does not itself establish that all hazardous energy has dissipated.
DOLD SAFEMASTER STS M11BM/K Trapped-Key Guard Lock at a Glance
Specification | Details |
Type | STS-M11BM/K in supplied manufacturer listing |
Function | Mechanical guard lock with separate actuator and forced key removal |
Sequence | First key inserted; second key and then actuator may be removed |
Construction | FRP configuration; stainless variants are separate selections |
System | Modular SAFEMASTER STS key-transfer architecture |
Application boundary | Guard access sequence; energy isolation and safe state defined separately |
Ordering | Exact key codes, actuator, mounting and unit sequence |
Design and Engineering Assessment
A trapped-key arrangement is a physical expression of a state machine. Every key release should correspond to a machine condition, and every retained key should prevent the relevant hazardous restart. Draw this sequence before selecting modules, especially where two gates, maintenance access or multiple people are involved.
The first released key must come from a condition that actually establishes the required safe state. A mechanism that only confirms a control command may leave inertia, pressure or a suspended load. Decide which energy sources require isolation, discharge, blocking or monitored stopping in the complete machine design.
The FRP construction and modular architecture do not make every STS assembly equivalent. Actuator geometry, mounting orientation, environmental exposure and key coding affect the installation. Keep the full sequence and exact hardware identity together when extending the system.
Map Entry and Exit States
Document where each key starts, which operation releases it, who retains it and how normal operation is restored. Address foreseeable shared-key use and the needs of every entrant.
Verify the exact M11BM/K assembly against the current manufacturer instructions and drawings. The suffix and module order are functional selection details rather than cosmetic naming.
Validate Mechanical Safeguarding
Use the approved machine-safety procedure to check key exchange, actuator release, attempted restart and exit/recovery. Inspect mechanical alignment and foreseeable loading without bypassing the protective arrangement.
Maintain controlled spare-key records and approved replacement units. A replacement that changes key coding or exchange sequence can change the protective behavior even when it mounts in the same place.
Applications and Selection
Industrial guarded accesses using a defined mechanical key-exchange sequence.
For DOLD SAFEMASTER STS M11BM/K Trapped-Key Guard Lock, define the actual machine duty before selecting an ordering configuration. Include the required operating point, available installation space, environment and control interfaces. The specification table describes the product or family; the surrounding machine determines which of those features matters for the intended job.
Price and Value
Request a quote for the exact ordering code, supply, contact arrangement, accessories and integration scope. Confirm the applicable instructions and documentation with the delivered configuration.
Compare complete installed alternatives using the same required protective function, diagnostic coverage, service procedure and acceptance criteria. Hardware cost alone does not represent the engineering and validation effort.
Pros and Cons
Advantages
Explicit two-key mechanical access sequence
Separate actuator supports guarded access
Part of a modular trapped-key architecture
Limitations
Safe energy state must be established by the full machine
Key control and multi-person access require design
Exact mechanical assembly and key codes are essential
Who Should Consider DOLD SAFEMASTER STS M11BM/K Trapped-Key Guard Lock?
Consider this configuration when industrial guarded accesses using a defined mechanical key-exchange sequence matches a documented project requirement. Preserve the complete selected identity, interfaces and accepted operating procedure for commissioning and maintenance.
DOLD SAFEMASTER STS M11BM/K Trapped-Key Guard Lock FAQ
What does M11BM/K do?
It is a mechanical guard-lock/key-transfer configuration with a separate actuator and forced key removal.
What sequence is described?
Inserting the first key permits removal of the second key and then the actuator.
Is it identical to every STS electrical switch?
No. STS contains distinct mechanical, electrical and power-interlocking configurations.
Does removing a key discharge stored energy?
No. The complete isolation and safe-state sequence must address each hazardous energy source.
Is FRP the same as a stainless configuration?
No. Confirm the selected construction and environmental limits.
Can one shared key protect every entrant?
Do not assume so. Design key retention and restart prevention for the actual access arrangement.
What should maintenance control?
Spare keys, approved module sequence, actuator alignment and complete replacement identity.
What should be confirmed before ordering?
Current assembly drawing, key codes, exact unit type, actuator, mounting and accepted access sequence.
Prices are indicative and may change. Confirm the final configuration, commercial terms and delivery schedule before ordering.
