
Monel K-500 Split lock washers
ASME B18.21.1ISO 9724
Monel K-500 split washers need an elastic recovery requirement alongside age-hardened strength in the nickel–copper alloy family. Section shape and final temper control compression behaviour; the assembly’s locking method is a separate design choice.
- MOQ
- 100PCS
- Samples · typical
- ~20 days
- Production · typical
- 25–35 days
- Heat treatment
- Annealed / age hardened
EN 10204 3.1 MTC + heat-number traceability
Which standard is on your order?
Raw Material Specifications
Dimension Reference
Heat Treatment
Annealed or age hardenedAnnealing provides a workable starting condition, while controlled aging develops the higher strength specified for age-hardened K-500.
What we can make in Monel K-500
Free state
The open helical shape supplies initial spring travel as a screw or nut is tightened. Free height and section size determine how much travel is available before the washer becomes flat.
Clamped state
Once flattened, little spring travel remains to compensate for settling. For an assembly needing controlled preload travel, compare a disc spring; for a vibration-critical joint, select a locking method validated for that joint.
- Form
- Split helical ring
- Key dimensions
- Bore · Section · Free height
- Assembly
- Under nut or bolt head
- Sizing
- Metric · Inch
- Final condition
- Annealed · age hardened
- Inspection
- Bore · Section width and thickness · Free height
Manufacturing route
Wire or profiled section is formed into the helical ring; the split, section and free height are controlled before final condition checks.
Heat treatment & final condition
Solution treatment and the specified aging condition are recorded against the production lot; final dimensions are checked after thermal processing.
Working performance
The spring heat-treatment condition is selected for working stress and temperature. Load at working deflection and permanent set are acceptance characteristics.
Where K-500 fits — and what matters

Offshore & Marine
Deck-equipment brackets and marine pump skidsMonel K-500 split lock washers fit under a bolt head or nut on deck-equipment brackets and marine pump skids when the assembly drawing calls for a helical washer. Compression and recovery belong to the washer specification. The assembled contact is exposed to saltwater, deposits and neighbouring metals.

Water Treatment & Desalination
Membrane-skid and pump supportsMonel K-500 split lock washers fit under a bolt head or nut on membrane-skid and pump supports when the assembly drawing calls for a helical washer. Compression and recovery belong to the washer specification. The water stream, cleaning cycle and retained liquid define exposure at the installed part.

Oil & Gas
Utility skids and instrument supportsMonel K-500 split lock washers fit under a bolt head or nut on utility skids and instrument supports when the assembly drawing calls for a helical washer. Compression and recovery belong to the washer specification. Utility connections and pressure-boundary parts have separate acceptance requirements on the equipment drawing.
Same split lock washer. Different material priorities.
Monel K-500 material dataInconel X-750
Age-hardened strength and a choice of hot-service heat treatments.
- Connection priority
- Elastic recovery after compression
- Spring treatment versus bolting treatment
- X-750 has several heat-treatment routes. The route for retained spring force is selected around relaxation and working stress; a bolting strength requirement calls for its own specified condition. At the split edges and compressed contact faces, the relevant metal temperature can differ from the process or furnace set point.
Inconel 718
Precipitation-hardened strength for compact, highly loaded connections.
- Connection priority
- Elastic recovery after compression
- Strength after aging
- Machine-stock properties and final aged properties describe different states. The final heat-treatment lot and mechanical results establish the strength available in the installed part. At the split edges and compressed contact faces, the relevant metal temperature can differ from the process or furnace set point.
Inconel 625
Solid-solution strength and resistance to aggressive process liquids.
- Connection priority
- Elastic recovery after compression
- Annealed or solution-annealed 625
- The delivery condition affects strength and high-temperature response. Keep the specified condition with the component’s mechanical acceptance; 718-style aging is not the strengthening route for 625. Include liquid retained at the split edges and compressed contact faces in the exposure description.
From drawing to documented delivery




- 01Drawing & BOMForm, dimensions and quantity
- 02Material & formingGrade, heat and manufacturing route
- 03Final inspectionGeometry, threads and ordered tests
- 04Documents & dispatchLot records and identified packing
Order documents
- Material identity
- UNS N05500 · heat number · ordered condition
- Final-part acceptance
- Lot-linked aging record and mechanical acceptance in the final condition. Load–deflection and permanent-set results for the specified spring geometry.
- Dimensional record
- Bore · Section width and thickness · Free height
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your K-500 split lock washer enquiry
Questions about K-500 split lock washers
Does corrosion-resistant stock automatically make a spring washer?
The stock needs a condition that provides the required elastic recovery. Record the final temper, compression behaviour and permanent set; a chemistry certificate alone does not describe the spring response.