Reaction Washer Pair
Gear-shaped wedge-locking washer system that provides the coaxial reaction interface and helps maintain preload under vibration.
Reaction Control
Reaction Washer
Systems
ToughTorq Reaction Washers combine a gear-shaped lower washer with a matched dual socket so torque reaction is contained coaxially at the fastener instead of through an external reaction arm. The wedge-locking washer pair helps preserve preload under vibration and dynamic loading while reducing reaction-arm pinch points and surface-contact requirements.
Reaction-Arm-Free Tightening
Contain reaction torque at the fastener
A matched dual socket engages both the fastener and the gear-shaped outer profile of the lower washer. Reaction torque is contained coaxially at the joint, eliminating the need for an external reaction arm while the wedge-locking washer pair helps preserve preload under vibration and dynamic loading.
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Reaction-arm-free tightening with a matched dual socket
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Wedge-locking anti-loosening principle
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Torque applied axially without an additional bending moment
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Gear-shaped lower-washer reaction profile
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Pre-assembled washer pairs for installation
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Low friction variation supports controlled tightening
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Protection against vibration-induced self-loosening
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Matched socket and adaptor configurations for powered torque tools
Technical Data
Published Reaction Washer specifications
Size Range
M16–M48 / 5/8–1-3/4 in
Material
1.1191 (C45E)
Hardness
485 ± 25 HV 0.3
Coating
Black zinc flake (flZnnc)
Corrosion Resistance
Minimum 1,000 hours NSS / ISO 9227
Bolt Strength
Through property class 12.9
Nut Strength
Through property class 12
Design Principle
DIN 25201 wedge-locking principles
Additional nominal sizes, materials, and coatings are available on request. The canonical catalog does not invent individual washer model numbers where the manufacturer documentation publishes only the verified size range.
System Components
Washer, dual socket & tool adaptor
Matched Dual Socket
Coaxial socket system that engages the fastener and the gear-shaped Reaction Washer profile so reaction torque is contained at the joint.
Optional Passive-Side Safety Washer
Friction-based backup washer for through-bolt connections where the passive-side nut or bolt head cannot be physically counter-held.
Tool Compatibility
Match the dual socket to the complete bolting system
Dual sockets can be configured for common electric, pneumatic, and hydraulic torque tools. The socket must match the torque-tool interface, fastener, and Reaction Washer size as one complete coaxial system.
✓The dual socket must match both the torque tool drive/interface and the selected Reaction Washer size.
✓Published Reaction Washer sizes cover M16–M48 (5/8–1-3/4 in); additional nominal sizes, materials, and coatings are available on request.
✓For through-bolt joints where the passive side cannot be counter-held, an optional passive-side safety washer may be used.
Applications
Petrochemical facilities
Renewable energy
Heavy industry
Plant construction
Large flange connections
High-cycle bolting
Restricted-access bolting
Vibration-critical bolted joints
Downloads
Reaction Washer technical resources
Distribution
Find a ToughTorq distributor
Connect with the ToughTorq distribution network for washer, socket, and torque-tool matching.
Find a DistributorPurchase & Application Support
Commercial support through JAM Torque
For purchasing, dual-socket matching, tool selection, and application support in JAM Torque's supported market, continue to JAMTorque.com.
Visit JAM Torque →