Monel K-500 Slotted & castle nuts
DIN 935-1ASTM B865
K-500 castle nuts add age-hardened nickel-copper strength to positively retained marine linkages. The split pin, cross-drilled shaft and nut condition must be specified together; a corrosion-resistant nut cannot compensate for a failed retaining pin.
- 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
Threads · Metric
Threads · Inch
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
Slotted nut
Use on drilled shafts and pins where a cotter pin retains the nut after adjustment. Slots in the hex body provide a lower axial envelope when the installation has limited clearance.
Castle nut
Use the raised slotted crown to position the cotter-pin path above the wrenching body. The crown needs clearance beyond the bearing assembly or linkage end.
Pin alignment
For wheel, pivot and linkage assemblies, align the slots with the cross-hole using the assembly’s preload or end-play procedure. The pin retains the nut; it does not set the bearing adjustment.
- Retention
- Slots · Split pin
- Mating part
- Cross-drilled bolt or shaft
- Patterns
- Slotted · Castellated
- Threads
- Metric · Inch
- Final condition
- Annealed · age hardened
- Inspection
- Slot width · Crown height · Pin clearance · Threads
Manufacturing route
Small lots use machined blanks. Volume nut blanks use a forming route compatible with the alloy before machining the bore and tapping.
Heat treatment & final condition
Solution treatment and the specified aging condition are recorded against the production lot; final dimensions are checked after thermal processing.
Finished geometry
Internal thread gauging, usable engagement and bearing-face alignment are checked after final processing.
Where K-500 fits — and what matters
Offshore & Marine
Marine pump shafts and linkage pinsMonel K-500 slotted & castle nuts retain marine pump shafts and linkage pins with a split pin through the nut slots and a cross-drilled shaft. Slot alignment establishes the final positive-retention position. The assembled contact is exposed to saltwater, deposits and neighbouring metals.
Water Treatment & Desalination
Treatment-pump shafts and actuator partsMonel K-500 slotted & castle nuts retain treatment-pump shafts and actuator parts with a split pin through the nut slots and a cross-drilled shaft. Slot alignment establishes the final positive-retention position. The water stream, cleaning cycle and retained liquid define exposure at the installed part.
Oil & Gas
Valve actuator shafts and linkage pinsMonel K-500 slotted & castle nuts retain valve actuator shafts and linkage pins with a split pin through the nut slots and a cross-drilled shaft. Slot alignment establishes the final positive-retention position. Utility connections and pressure-boundary parts have separate acceptance requirements on the equipment drawing.
Same slotted & castle nut. Different material priorities.
Monel K-500 material dataInconel 625
Solid-solution strength and resistance to aggressive process liquids.
- Connection priority
- Nut preload with separate positive pin retention
- 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 pin slots, cross-drilled shaft and bearing face in the exposure description.
Super Duplex 2507
Super-duplex strength and resistance to chloride pitting.
- Connection priority
- Nut preload with separate positive pin retention
- Final duplex structure
- S32750 chemistry and final solution treatment belong together. Forming, section size and cooling affect the structure represented by the mechanical and corrosion records. Include liquid retained at the pin slots, cross-drilled shaft and bearing face in the exposure description.
Duplex 2205
Duplex strength and chloride-corrosion resistance.
- Connection priority
- Nut preload with separate positive pin retention
- S31803 or S32205
- The specified UNS fixes the chemistry. Solution treatment, section size and the ordered mechanical or corrosion tests establish the final duplex condition. Include liquid retained at the pin slots, cross-drilled shaft and bearing face 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.
- Dimensional record
- Slot width · Crown height · Pin clearance · Threads
- Traceability
- EN 10204 3.1 material certificate · production lot · identified packing
Build your K-500 slotted & castle nut enquiry
Questions about K-500 slotted & castle nuts
What must be specified with a castle nut?
The cross-drilled shaft, retaining pin material and slot geometry complete the retention system. Slot alignment follows the assembly tightening procedure; the pin does not generate the joint’s clamp load.