Lenze BFK458 Series Electromagnetic Spring Brakes: BFK458-25 (400 N.M) 180VDC

Technical Dossier

Product Details And Specifications

Lenze BFK458 Series: Comprehensive Module Range and Technical Overview

The Lenze BFK458 series represents one of the most widely deployed electromagnetic spring-applied brake families in global heavy industry. Installed across chemical processing plants, nuclear power facilities, oil refineries, steel mills, and offshore platforms, the BFK458 range is engineered for fail-safe braking on AC and DC motor shafts where loss of power must result in immediate mechanical arrest. The series covers torque ratings from 1.5 N.m up to 600 N.m, accommodating drive systems from fractional-kilowatt conveyors to multi-megawatt hoisting and positioning applications. Its modular coil-and-armature architecture allows field replacement of friction linings and coil assemblies without full brake removal, a critical factor in continuous-process industries where unplanned downtime carries significant financial and safety consequences. The BFK458 platform is fully compatible with Lenze's 8400, 9300, and i700 inverter families, as well as third-party VFDs, making it a cross-platform standard in European and Asian industrial installations.

The Evolution of BFK458 Architecture

The BFK458 series was introduced by Lenze as a successor to the earlier BFK400 and BFK450 brake families, consolidating torque ranges and standardizing coil voltage options to 24 VDC, 90 VDC, 180 VDC, and 205 VDC across the product line. Early BFK458 units (pre-2005) used a single-piece friction disc assembly; post-2008 revisions introduced a segmented lining design that extended service intervals by approximately 40% under continuous-duty cycling. The 180 VDC coil variant — as found in the BFK458-25 (400 N.M) 180VDC — became the dominant specification for crane and hoist applications where rectified single-phase supply is standard. From 2015 onward, Lenze introduced enhanced IP54 and IP65 enclosure options for the BFK458 range to address washdown and outdoor installation requirements. As of 2024, the BFK458 series is in a mature/sustained phase: Lenze continues to supply spare coils, friction discs, and complete assemblies, but the platform is not receiving new feature development. For new installations, Lenze's BFK460 series offers improved thermal management, but BFK458 remains the dominant installed base for retrofit and maintenance sourcing globally.

BFK458 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified BFK458 series production range, organized by torque class. Each entry reflects a distinct mechanical and electrical specification:

BFK458-06 (6 N.M) 24VDC: Compact spring brake for small servo and positioning axes, 24 VDC coil, flange-mount.

BFK458-06 (6 N.M) 90VDC: 90 VDC coil variant of the 6 N.m frame; suited for DC bus-powered brake circuits.

BFK458-08 (10 N.M) 24VDC: 10 N.m holding torque, 24 VDC, standard for light conveyor and packaging line motors.

BFK458-08 (10 N.M) 180VDC: 180 VDC coil, 10 N.m; used on single-phase rectified brake supply circuits in material handling.

BFK458-10 (25 N.M) 24VDC: Mid-range torque, 24 VDC; common on gearmotor assemblies in food and beverage processing.

BFK458-10 (25 N.M) 180VDC: 180 VDC, 25 N.m; standard specification for European crane auxiliary drives.

BFK458-14 (60 N.M) 24VDC: 60 N.m, 24 VDC; applied on medium-duty hoists and vertical transport systems.

BFK458-14 (60 N.M) 180VDC: 180 VDC coil, 60 N.m; the dominant variant for overhead crane main hoist braking in 180 VDC rectified systems.

BFK458-16 (100 N.M) 24VDC: 100 N.m holding torque, 24 VDC; used on large conveyor drives and industrial elevators.

BFK458-16 (100 N.M) 180VDC: 180 VDC, 100 N.m; standard for port crane slewing and travel drives.

BFK458-20 (200 N.M) 90VDC: 200 N.m, 90 VDC; applied in steel mill roll table and coiler drive systems.

BFK458-20 (200 N.M) 180VDC: 180 VDC, 200 N.m; high-torque variant for heavy hoist and winch applications.

BFK458-25 (400 N.M) 180VDC: 400 N.m holding torque, 180 VDC coil; primary specification for main hoist braking on overhead cranes, ship-to-shore cranes, and heavy industrial hoisting equipment. Fail-safe spring-applied, electromagnetically released. This is the reference SKU for this listing.

BFK458-25 (400 N.M) 205VDC: 205 VDC coil variant of the 400 N.m frame; used in markets with 230 VAC single-phase rectified brake supply.

BFK458-30 (600 N.M) 180VDC: Maximum torque variant in the BFK458 range; 600 N.m, 180 VDC; deployed on main hoists of metallurgical cranes and heavy-lift offshore equipment.

BFK458-30 (600 N.M) 205VDC: 205 VDC, 600 N.m; European grid variant for the largest BFK458 frame size.

Sourcing Hard-to-Find & Obsolete BFK458 Parts

DriveKNMS maintains a dedicated inventory program for the Lenze BFK458 series, with particular focus on high-torque variants (200 N.m–600 N.m) and 180 VDC coil assemblies that are subject to extended lead times from standard distribution channels. For plants operating BFK458 units installed prior to 2010, original coil assemblies and friction disc kits may no longer be available through Lenze's standard spare parts network. DriveKNMS sources these components through verified secondary market channels, including decommissioned equipment recovery and authorized surplus inventory from European OEM integrators. All sourced units are subject to full electrical and mechanical inspection before dispatch. For critical applications — crane main hoists, nuclear auxiliary systems, offshore winches — DriveKNMS can provide documentation packages including test records and traceability certificates upon request. Customers requiring long-term maintenance contracts for BFK458-equipped fleets are encouraged to contact the technical team directly to discuss consignment stock arrangements.

Quality Control for the BFK458 Range

The BFK458 series presents specific inspection requirements due to its spring-applied mechanical design and the criticality of its fail-safe function. DriveKNMS applies the following test protocol to all BFK458 units processed through its facility:

Coil resistance measurement: DC resistance of the electromagnet coil is measured and compared against Lenze's published nominal values for each voltage variant (24 V, 90 V, 180 V, 205 V). Deviation beyond ±5% indicates coil degradation or winding damage.

Insulation resistance test: Megohm testing at 500 VDC between coil winding and brake body to verify insulation integrity. Minimum acceptable value: 100 MΩ.

Air gap verification: The working air gap between armature plate and electromagnet face is measured with feeler gauges and compared against the series-specific tolerance band. Excessive air gap indicates friction lining wear beyond service limit.

Spring force assessment: Static spring force is verified to confirm the brake will engage at rated torque on power loss. This is particularly critical for the BFK458-25 (400 N.M) and BFK458-30 (600 N.M) variants used in crane hoist applications.

Functional engagement/release cycle test: The brake is energized and de-energized under controlled conditions to verify clean armature travel, absence of mechanical binding, and correct release voltage threshold.

Friction surface inspection: Lining thickness is measured and surface condition assessed for glazing, contamination, or uneven wear patterns that would compromise braking torque consistency.

For sourcing inquiries, technical specifications, or long-term maintenance support for the Lenze BFK458 series: