Overview
The INTORQ BFK458 is an electromagnetically released, spring-applied brake supplied by Motordrives Australia for industrial drive systems across Australia. The brake operates as a fail-safe device: in its de-energised state, pressure springs clamp the rotor between the armature plate and a counter friction surface, applying braking torque automatically whenever power is lost. Energising the coil draws the armature plate against the stator, releasing the rotor to rotate freely.
The BFK458 series spans nine frame sizes (06 through 25), covering rated torques from 1.5 Nm up to 600 Nm with standard or wear-resistant linings, and up to 720 Nm with high-friction-coefficient (HFC) linings. This range suits everything from small holding brakes on light-duty axes through to heavy industrial operating and emergency-stop brakes.
Motordrives Australia can help confirm the correct size, design type, coil voltage and optional features for your specific drive, motor end shield and safety requirements.
Design Variants
The BFK458 is available in three basic module configurations:
- Design E (adjustable): Braking torque can be reduced via a central torque adjustment ring, with reduction available in defined latched-in steps per size.
- Design N (fixed): A fixed-torque design without adjustment, using the same basic layout as Design E.
- Design L (long-life): Built for sizes 06 to 12 with a low-backlash armature plate, shear-protected pressure springs and an aluminium rotor with a toothed intermediate ring for reduced wear of the friction lining and gear teeth.
A double spring-applied brake configuration is also available, mounting two brake stators in series via an intermediate flange for redundant braking applications.
Key Features
- Fail-safe operation: the rotor is clamped by spring force whenever the coil is de-energised, so the brake applies automatically in the event of a power interruption.
- Hand-release (optional): allows the brake to be temporarily released by hand when power is unavailable, springing back automatically once released. Can be retrofitted to an installed brake.
- Micro-switch (optional): monitors either brake release (motor only starts once the brake has released) or friction lining wear (power is cut once the air gap exceeds the permitted limit).
- Cold Climate Version (CCV): extends the standard -20°C to +40°C operating range down to -40°C for cold-environment installations. Note the CCV temperature range is not permitted when the brake is used as a certified safety brake.
- Friction lining options: Standard (ST) and Wear-Resistant (WR) linings share the same rated torque table; a High-Friction Coefficient (HFC) lining option increases available torque per size at the cost of reduced permissible friction work at higher speeds.
Safety Brake Applications
The BFK458 series is certified for use as a “Safety Brake” — as an operating brake, holding brake, or holding brake with emergency-stop functionality — in applications requiring a safety certificate to DIN EN ISO 13849. For safety-rated use:
- The selected characteristic torque must, at minimum, match the standard braking torque for that size, since the safety function is calculated on 80% of the brake’s characteristic torque being sufficient.
- Fastening screws must be strength class 8.8, tightened to the specified torque with a tolerance of ±10%, using a noise-reduced rotor with a toothed intermediate ring.
- The CCV low-temperature range and the optional micro-switch are not covered under the safety certificate.
- Friction lining wear and emergency-stop loading are not included in the standard safety calculation and must be checked separately for each application.
Performance level classification follows DIN EN ISO 13849-1:2015; detailed safety characteristic data is available on request through Motordrives Australia.
Technical Specifications Snapshot
| Size | Rated Torque (Standard/WR) | Max. Speed (horizontal mount) | Degree of Protection |
|---|---|---|---|
| 06 | 1.5 – 6 Nm | 6000 rpm | IP54 |
| 08 | 3.5 – 12 Nm | 5000 rpm | IP54 |
| 10 | 7 – 23 Nm | 4000 rpm | IP54 |
| 12 | 14 – 46 Nm | 3600 rpm | IP54 |
| 14 | 25 – 80 Nm | 3600 rpm | IP54 |
| 16 | 35 – 125 Nm | 3600 rpm | IP54 |
| 18 | 65 – 235 Nm | 3600 rpm | IP54 |
| 20 | 115 – 400 Nm | 3600 rpm | IP54 |
| 25 | 175 – 600 Nm | 3000 rpm | IP54 |
Full braking torque tables, air gap specifications, coil power data, switching times and screw torque values for each size are available in the INTORQ BFK458 Operating Instructions (BA 14.0168) — contact Motordrives Australia for a copy.
Common Applications
- Holding brakes on vertical or inclined drive axes, preventing unintended movement when power is removed
- Operating brakes used as the primary stopping mechanism for general machinery
- Holding brakes with emergency-stop functionality on safety-rated systems
- Conveyor, hoist, lift and material handling drives requiring fail-safe braking
- OEM machine builds where a compact, field-proven brake module is required alongside an existing motor
Selection Considerations
Correct BFK458 selection depends on confirming the required braking torque against the drive’s load, speed and duty cycle, along with the motor end shield dimensions, available coil voltage, and whether hand-release or micro-switch monitoring is needed. Applications with frequent cycling or high operating speeds should be checked against the permissible friction work and operating frequency limits for the chosen friction lining (Standard, WR or HFC).
For safety-rated holding or emergency-stop applications, the brake’s characteristic torque, screw specification and lining type must all meet the conditions set out in DIN EN ISO 13849 for the system’s required performance level.
Motordrives Australia can help work through these selection criteria using the full INTORQ technical documentation.
Support And Enquiries
Motordrives Australia supplies and supports the INTORQ BFK458 spring-applied brake range for Australian machine builders, maintenance teams and OEM equipment manufacturers.
For assistance with sizing, torque selection, hand-release or micro-switch configuration, or safety brake certification requirements, contact our team with your application’s torque, speed, duty cycle and mounting details.
