The friction pairings perform the physical work of the braking system. Powerful forces transform kinetic energy into heat, causing the train to brake. Optimal friction technologies require a perfectly balanced “pairing”. Knorr-Bremse can supply custom, application-specific friction material pairings for virtually any type of train, meeting almost every rail industry standard around the world. The company’s in-depth understanding of what constitutes the right friction pairing ensures optimized life cycle costs, generating added value for the customer.
All friction pairings are grouped under the heading of Friction Technologies. Knorr-Bremse’s individual product technologies for friction material – sintered and organic pads and blocks – are bundled under its three Friction product ranges: 'ProPad', 'ProBlock' and 'UltraPad'. The brake discs are marketed under the names 'UltraDisc', 'ProDisc' and 'LightDisc'.
Pads
In our brake pad and block ranges, the prefix “Ultra-” denotes sintered products, while “Pro-” denotes organic products. Knorr-Bremse’s ProPad organic brake pads are available as standard brake pads and for hydraulic braking system applications. The 'UltraPad family' of sintered pads includes the high-performance sintered pads 'UltraPad Flex' and 'UltraPad Extreme' (also known as ISOBAR®).
Blocks
In our brake block range, the 'ProBlock family' features quiet, low-wear organic brake blocks including the “whisper brake” LL blocks and K blocks for freight cars.
Discs
To achieve the ideal friction pairing, Knorr-Bremse can choose from a modular range of brake discs of many different thicknesses and diameters. The axle- or wheel-mounted discs are available in the widest range of steel, grey cast iron, nodular cast iron and aluminum versions.
Contact
Sales Rail Knorr-Bremse Global Rail Holding GmbH
80809 München
Deutschland - Germany
sales.sfs@knorr-bremse.com
Friction Technologies – Products in Detail
System competence and global know-how
With the system competence and global know-how of Knorr-Bremse, Friction Technologies provide the most comprehensive, individual and suitable offer of friction products for all train applications.
Best friction pairing
Best friction pairing selected for maximizing performance and operating life, increasing sustainability and minimizing costs. Achieved with a perfectly balanced braking system. As a supplier of brakes and a full range of friction products, Knorr-Bremse is in an ideal position to design the best system.
Brake Pads & Blocks
Knorr-Bremse Friction Technologies offers a full range of sinter and organic brake pads and blocks. Our customers can rely on unique system expertise based on integrated engineering to achieve best brake performance.
Product families
Product family Description UltraPad Sinter pads both in flexible and rigid designs are composed mainly of sinter material elements in different forms and sizes. High technology degree for the most demanding applications. ProPad Produced with a variety of organic friction materials, organic pads cover the demands of a wide range of applications. Available both in standardized forms like UIC/KRS or specific design for hydraulic applications. ProBlock Wide range of organic material blocks both in UIC and AAR forms to cover a wide range of applications. Developing technologies towards wear- and noise-optimized products.
Brake Discs
Knorr-Bremse Friction Technologies offers a full range of brake discs made out of various materials which are clustered into the following product families
Product families
Product family Material Designed for ProDisc Gray cast iron … cost efficiency and a wide-range of applications
UltraDisc Steel … high speed applications with highest demands for brake energies and associated surface temperatures LightDisc Aluminum … saving weight and energy
UltraPad
UltraPad is the sintered brake pad family from Knorr-Bremse Friction Technologies. Sinter pads both in flexible and rigid designs are composed mainly of sinter material elements in different forms and sizes and offer a high technology degree for the most demanding applications.
- Knorr-Bremse offers a full range of flexible sinter brake pad designs for high-energy application
- High friction stability at high temperatures and reduced hot spots on brake disc
- High mechanical resistance
- Supply chain which supports unique overhaul concept, elements produced at Knorr-Bremse site
- Extensive portfolio with global certifications
The family comprises UltraPad Flex for application speeds above 200 km/h – available in UIC, KRS and Tetra/Penta designs – and UltraPad Extreme for application speeds above 250 km/h.
UltraPad Flex
UltraPad Extreme
ProPad
ProPad stands for the organic brake pads from Knorr-Bremse. Produced with a variety of organic friction materials, organic pads cover the demands of a wide range of applications and are available both in standardized forms like UIC/KRS or specific design for hydraulic applications.
- Organic friction materials
- Large product portfolio covering the specific demands of each application
- Noise-optimized design to avoid squealing
- Standard UIC dovetail designs or specific application-related hydraulic designs
- Extensive portfolio with global certifications
The ProPad range covers three lines: specific designs fitting into all hydraulic interfaces, an extensive UIC portfolio with global certifications (UIC, GOST, ...) and the KRS design with 15% increased lifetime in friction pairing.
ProPad product lines
Hydraulic UIC KRS Specific designs fitting into all hydraulic interfaces Standardized global design 15% increased lifetime in friction pairing
ProBlock – UIC/TSI
ProBlock is the organic brake block family from Knorr-Bremse, offering a wide range of organic material blocks in UIC form. The technologies are being developed towards wear- and noise-optimized products.
- Organic blocks covering demands of all UIC/TSI application types
- High and low friction levels optimized for each application
- Low wear levels, compared to gray cast iron blocks, 3 times longer lifetimes
- Standardized forms and wide range of friction material available, providing a large range of products
The UIC range includes LL and L blocks with a low friction level for grey-cast iron retro-fit, reducing noticeable noise by 50%, K blocks with a high friction level for modern freight cars (blocks for CFCB suitable for s and ss traffic) as well as metro blocks with a high friction level for a broad variety of applications, e.g. metro with ATO.
ProBlock – UIC/TSI product lines
LL Blocks – L Blocks K Block Metro Blocks Blocks with low friction level for grey-cast iron retro-fit; reduction of noticeable noise by 50% Blocks with high friction level for modern freight cars; blocks for CFCB suitable for s and ss traffic Blocks with high friction level for a broad variety of applications (e.g. metro with ATO, etc.)
ProBlock – AAR
For the AAR markets, ProBlock provides standardized forms and a wide range of friction material, with product lines offering a differentiated value proposition for the customer.
- Applications for all AAR markets
- Product lines with differentiated value proposition for the customer
- Standardized forms and wide range of friction material available, providing a big range of products
- Wheel Saver tread conditioning brake shoes repair wheel tread defects keeping wheels in service longer.
For freight cars, ChangeSaver provides 45% more friction material than all other AAR-certified products, ValueSaver combines optimized friction performance with a competitive price design, and WheelSaver delivers tread conditioning and low fade friction performance. For locomotives, ProShoe High Friction offers different mixes and forms with proven durability and life-cycle value, while ProShoe Low Friction formulas are designed for today’s service environments as replacements for cast iron shoes. For coaches, ProShoe High Friction formulas and forms are specifically designed for commuter rail service environments.
Freight Shoes
ChangeSaver ValueSaver WheelSaver Provides 45% more friction material than all other AAR-certified products Optimized friction performance, competitive price design Tread conditioning and low fade friction performance
Locomotive Shoes
ProShoe High Friction ProShoe Low Friction Different mixes and forms produce proven durability and life-cycle value Low friction formulas designed for today’s service environments are replacements for cast iron shoes
Coaches
ProShoe High Friction Formulas and forms specifically designed for commuter rail service environments
Production Excellence & References
With one of the world’s broadest portfolios, Knorr-Bremse assures high-quality production and supply chain excellence. Knorr-Bremse’s leading rail friction factories focus on the product portfolio of the world’s largest markets. Our facilities are equipped with the latest production technology to ensure high-quality, reliable products.
Main site for UIC material
- Manufacturing in Pamplona, Spain, since 1961
- Products: Organic brake pads · Organic brake blocks · Sinter friction elements
Main site for AAR material
- Manufacturing in West Chicago since 1977
- Products: AAR brake shoes - Organic brake blocks (= shoes) & semi-metallic wheel-conditioning shoes
Manchester site
- Manufacturing in Manchester since 1879, owned by Knorr-Bremse since February 2016
- Products: Organic metro brake blocks · Organic freight brake blocks
References (extract)
Knorr-Bremse delivers friction products all over the world with local sales teams
Axle-mounted brake discs
Axle-mounted brake discs are available in all three product families – ProDisc and ProDisc Axle Plus in grey cast iron, UltraDisc Axle and UltraDisc Axle Plus in steel as well as LightDisc Axle in aluminum – and cover the full range of vehicle types.
Product families and materials
ProDisc Axle
ProDisc Axle Plus UltraDisc Axle
UltraDisc Axle Plus LightDisc Axle Grey cast iron Steel Aluminum
- Available size: 350 – 700 mm
- Available width: 45 – 170 mm
- All axle-mounted discs are available as solid- and split discs
- Flat seated disc is the standard for Knorr-Bremse axle-mounted discs
- Project specific disc designs available (e.g. mono block discs, specific flange brake disc designs for LRV applications)
- Compliant with all international standards (EN14535, UIC, GOST, CRCC, etc.)
ProDisc Axle Plus / UltraDisc Axle Plus: Axle-mounted brake discs for highest brake loads and vibration levels
The Plus variants are designed for the highest brake loads and vibration levels. Four design features characterize the concept:
- ➊ Reinforced connection friction ring to hub: Highest strength waisted shankbolting · Vibration protected thread on bolts
- ➋ Advanced hub: Optimized shape for heavy duty shock and vibration loads · Strengthened flanges
- ➌ Friction ring design for highest thermal and mechanical loads: Increased permitted thermal load · Form-fit centering supported by sliding sleeves
- ➍ Sliding keys transferred from service-proven wheel-mounted disc: Design variant as sleeves for combined function: guiding and bolting at same place · Shock and vibration protected centering
Wheel-mounted brake discs
Wheel-mounted brake discs are likewise offered in grey cast iron (ProDisc Wheel), steel (UltraDisc Wheel and UltraDisc Wheel Lite) and aluminum (LightDisc Wheel). The standardized interface to the wheel ensures highest thermal capacity and minimized weight.
Product families and materials
ProDisc Wheel UltraDisc Wheel
UltraDisc Wheel Lite LightDisc Wheel Grey cast iron Steel Aluminum
- Available size: 370 – 1.085 mm
- Available width: 120 – 155 mm
- Standardized interface to wheel ensures highest thermal capacity and minimized weight
- Lite version for medium speed applications (e.g. regional commuter) – see UltraDisc Wheel Lite
- Most wheel-mounted discs are available as solid- and split disc version
- Project specific disc designs available
UltraDisc Wheel Lite: Innovative low-weight steel wheel-mounted brake disc
- ➊ Weight optimization (-20%) for applications up to 160 (200) km/h
- ➋ Service-proven casted steel technology
- ➌ Stress-relieving grooves in friction face
- ➍ Service-proven waisted bolts and lock nuts
- ➎ Slide key centering at 6 places
- ➏ Service-proven “3-Point-Support” on wheel web: Parallel friction faces for constant friction performance and wear behavior · Compatibility to existing wheels · Fits to standard KB interface
UltraDisc Wheel Eco: Innovative wheel mounted brake disc with minimized ventilation loss
- ➊ Bolting domes for fastening with 12 waisted bolts and lock nuts (KB standard interface)
- ➋ Optimized fin design to reduce air flow
- ➌ Centering domes for slide key centering at 6 places
- Same structural and thermal performance as KB standard design & compatible with established KB interface
- Wheel-mounted brake disc with reduced ventilation loss of up to -70%
- Significantly contributes to train energy saving – Example calculation for high-speed train applications
Example calculation for high-speed train applications
Annual milage 700.000 km Route profile per round-trip 1300 km (¼ high speed – 320 km/h, ¾ conventional – 180 km/h) Wheel mounted brake discs per trainset 64 Reduced ventilation losses per disc and round-trip 35 MJ Reduced ventilation losses per disc and round-trip 1.2 Tera Joule (equivalent to annual electricity consumption of ~100 households
Reduced air flow and air velocity in between wheel body and brake disc without sacrificing structural and thermal performance
Advanced materials for brake discs
Beyond the established materials, Knorr-Bremse is advancing brake disc materials in two directions: a high performance grey cast iron formula for applications with increased thermal load and a high performance aluminum alloy for weight reduction of railway vehicles.
High performance grey cast iron brake disc for applications with increased thermal load
- Grey cast iron material with improved material properties
- Higher thermal resilience
- Higher resistance to surface cracks
- Increase application range with high performance grey cast iron
- Applicable for axle-mounted and wheel-mounted brake discs
High performance aluminum alloy brake disc for weight reduction of railway vehicles
The aluminum alloy brake disc achieves a weight reduction of ~70 kg in relation to a standard steel wheel-mounted brake disc. Fatigue tests for a Chinese-standard regional commuter application up to 200 km/h revealed no cracks, good surface status, good bolt fixation and a stable friction coefficient:
- ➊ Brake disc surface after fatigue test
- ➋ UltraPad Flex pad friction surface after fatigue test
- ➌ Dismantled bolts after fatigue test
- ➍ Thermography of disc during fatigue test
- Weight reduction of ~70 kg in relation to a standard steel wheel-mounted brake disc
- Energy savings due to reduced weight (particularly significant in the case of a metro application)
- Fatigue tests for Chinese-standard regional commuter application up to 200 km/h revealed no cracks, good surface status, good bolt fixation and stable friction coefficient
Production Excellence & References
With one of the biggest production footprints, Knorr-Bremse assures supply chain excellence. Our facilities are equipped with state-of-the-art production technology to ensure high-quality and reliable products.
Knorr-Bremse Rail, Berlin (Germany)
- Manufacturing since 1996
- Products: Axle- and wheel-mounted discs for all types of rail vehicles
Knorr-Bremse Rail, Suzhou (China)
- Manufacturing since 2005
- Products: Axle- and wheel-mounted discs for EMUs/DMUs and locomotives
Knorr-Bremse Rail, Palwal (India)
- Manufacturing since 2014
- Products: Axle- and wheel-mounted discs
New York Air Brake, Watertown (USA)
- Manufacturing since 2024
- Products: Axle- and wheel-mounted discs
References (extract)
Knorr-Bremse delivers brake discs all over the world with local sales teams
One of the most advance testing facilities worldwide allows Knorr-Bremse to close up the cycle for every customer application with the assurance that the most reliable braking system has been designed for our customers. Knorr-Bremse‘s holistic approach as a system supplier puts the customer specific applications into the focus. This expertise culminates in the ability to optimize life-cycle costs of friction pairs and creating value-add for customers by:
- Optimizing pad design (flexible vs. rigid design) and wear volume (KRS shape)
- Optimizing heat flow and heat distribution on friction surface of disc and pad
- Optimizing cooling performance of brake disc and brake pad
- Avoiding hot spots on friction surfaces
Thermographic investigation of friction pair with state-of-the-art testing equipment in the Knorr-Bremse technology center:
Environmental and sustainability aspects as part of friction pairing excellence
Particulate matter emissions from the friction pair have become of crucial importance for many municipal and federal railway operators in near future. Knorr-Bremse takes environmental protection and health safety issues in that regard seriously an addresses this by:
- The ability to measure particulate matter emission from the friction couple during dynamometer testing of any application
- Continuously contributing to the preparation of industry standards for particulate matter emission measurements
- Putting the reduction of particulate matter emissions to the heart of future friction pair combinations (brake pads and brake discs / brake blocks and wheels)
Comparison of particulate matter emission for different brake pads and particle sizes for a generic EMU application:
PMx in % relative to the reference product
