Alloy K500 - UNS N05500

Alloy K500, UNS N05500, is commonly associated with QQ-N-286 - ASTM B865.
Alloy K500 is commonly known as Monel® K500. Alloy K500 is an age-hardenable Nickel-Copper alloy.
Mechanical properties here.


Ni Mn Si Fe Al S C
Max % 1.50 0.50 2.00 3.15 0.010 0.18
Min % 63.0 2.35

Typical Inventory

Round Bar, Plate, Machined, Forge

Product Description

Alloy K500, also called MONEL K500, is a age-hardenable nickel-copper alloy that combines the corrosion resistance properties of alloy 400 with high strength corrosion fatigue and erosion resistance properties.

Alloy K500 is precipitation hardenable through the additions of aluminum and titanium. The chemical composition of alloy K500 retains the excellent corrosion resistant characteristics of alloy 400. When compared with alloy 400, alloy K500 has enhanced strength and hardness after precipitation hardening. Alloy K500 has approximately three (3) times the yield strength and double the tensile strength of alloy 400. Alloy K500 can be further strengthened by cold working before the precipitation hardening.

Alloy K500 should be annealed when welded and the weldment then stress relieved before aging.

General Data

  • Excellent mechanical properties from sub-zero temperatures up to about 480C.
  • Corrosion resistance in an extensive range of marine and chemical environments from pure water to non-oxidising mineral acids, salts, and alkalis.
  • Non-magnetic.


Typical applications for alloy K500 that take advantage of high strength and corrosion resistance are pump shafts, impellers, propeller shafts, valve components for ships and offshore drilling towers, bolting, oil well drill collars, and instrumentation components for oil and gas production. It is particularly well suited for centrifugal pumps in the marine industry because of its high strength and low corrosion rates in high-velocity sea water.

High Performance Alloys stocks Alloy K500 in a range of cold drawn, annealed and aged, and hot finished and aged. Material can be supplied in random lengths, cut to order or machined to your specifications. Machining includes drilling, turning, tapping, threading, CNC shapes, flanges, and more.

  • Pump shafts, impellers, propeller shafts.
  • Pumps and valves used in the manufacture of perchlorethylene, chlorinated plastics.
  • Valve components for ships and offshore drilling towers.
  • Instrumentation components for oil and gas production.
  • Oil well drill collars.
  • Particularly well suited for centrifugal pumps.
  • Equipment for processes utilising halide or acid catalysts.

Mechanical Properties

The typical properties listed can usually be provided in rounds, sheet, strip, plate, & custom forgings. We have the equipment to produce small quantities in special sizes to meet our customers’ specific needs.

Condition Ultimate Tensile ksi (MPa) 0.2% Yield Strength ksi (MPa) Elong. % in 2 in. Hardness Rockwell C (HRC)
Min Cold Worked/SR Over 1(25.4) to 3 140 (965) 100 (690) 17.0 29
Max Hot Worked/ Aged Hardened 140 (965) 100 (690) 20.0 27

Common Specifications

Please, note that the specs listed are for reference and are not comprehensive nor indicative of the actual specifications listed on the Material Test Report (MTR). If you have a special spec requirement, then please reach out to our sales department at 1-800-472-5569.

Form Standard
Metal Type UNS N05500
Bar ASTM B865, QQ-N-286
Wire AMS 4676
Sheet ASTM B865, QQ-N-286
Plate ASTM B865, QQ-N-286
Forging QQ-N-286
Weld Wire FM 60 ERNiCu-7
Weld Electrode FM 190 ENiCu-7
DIN 2.4375


Nickel and cobalt based alloys can be difficult to machinine. However, it should be emphasized that these alloys can be machined using conventional production methods at satisfactory rates. These alloys harden rapidly, generate high heat during cutting, weld to the cutting tool surface and offer high resistance to metal removal because of their high shear strengths. The following are key points which should be considered during machining operations:

  • CAPACITY - Machine should be rigid and overpowered as much as possible.
  • RIGIDITY - Work piece and tool should be held rigid. Minimize tool overhang.
  • TOOL SHARPNESS - Make sure tools are sharp at all times. Change to sharpened tools at regular intervals rather than out of necessity. A 0.015 inch wear land is considered a dull tool.
  • TOOLS - Use positive rake angle tools for most machining operations. Negative rake angle tools can be considered for intermittent cuts and heavy stock removal. Carbide-tipped tools are suggested for most applications. High speed tools can be used, with lower production rates, and are often recommended for intermittent cuts.
  • POSITIVE CUTS - Use heavy, constant, feeds to maintain positive cutting action. If feed slows and the tool dwells in the cut, work hardening occurs, tool life deteriorates and close tolerances are impossible.
  • LUBRICATION - lubricants are desirable. Soluble oils are recommended especially when using carbide tooling. Detailed machining parameters are presented Tables 16 and 17. General plasma cutting recommendations are presented in Table 18.

Table 16
Operations Carbide Tools
Roughing, with severe interruption Turning or Facing C-2 and C-3 grade: Negative rake square insert, 45 degree SCEA1, 1/32 in. nose radius. Tool holder: 5 degree neg. back rake, 5 degree neg. side rake. Speed: 30-50 sfm, 0.004-0.008 in. feed, 0.150 in depth of cut. Dry2, oil3, or water-base coolant4.
Normal roughing Turning or Facing C-2 or C-3 grade: Negative rate square insert, 45 degree SCEA, 1/32 in nose radius. Tool holder: 5 degree neg. back rake, 5 degree neg. side rake. Speed: 90 sfm depending on rigidity of set up, 0.010 in. feed, 0.150 in. depth of cut. Dry, oil, or water-base coolant.
Finishing Turning or Facing C-2 or C-3 grade: Positive rake square insert, if possible, 45 degree SCEA, 1/32 in. nose radius. Tool holder: 5 degree pos. back rake, 5 degree pos. side rake. Speed: 95-110 sfm, 0.005-0.007 in. feed, 0.040 in. depth of cut. Dry or water-base coolant.
Rough Boring C-2 or C-3 grade: If insert type boring bar, use standard positive rake tools with largest possible SCEA and 1/16 in. nose radius. If brazed tool bar, grind 0 degree back rake, 10 degree pos. side rake, 1/32 in. nose radius and largest possible SCEA. Speed: 70 sfm depending on the rigidity of setup, 0.005-0.008 in. feed, 1/8 in. depth of cut. Dry, oil or water-base coolant.
Finish Boring C-2 or C-3 grade: Use standard positive rake tools on insert type bars. Grind brazed tools as for finish turning and facing except back rake may be best at 0 degrees. Speed: 95-110 sfm, 0.002-0.004 in feed. Water-base coolant.
1 SCEA - Side cutting edge angle or lead angle of the tool.

2 At any point where dry cutting is recommended, an air jet directed on the tool may provide substantial tool life increases. A water-base coolant mist may also be effective.

3 Oil coolant should be premium quality, sulfochlorinated oil with extreme pressure additives. A viscosity at 100 degrees F from 50 to 125 SSU.

4 Water-base coolant should be premium quality, sulfochlorinated water soluble oil or chemical emulsion with extreme pressure additives. Dilute with water to make 15:1 mix. Water-base coolant may cause chipping and rapid failure of carbide tools in interrupted cuts.

Table 17
Operations Carbide Tools
Facing Milling Carbide not generally successful, C- grade may work. Use positive axial and radial rake, 45 degree corner angle, 10 degree relief angle. Speed: 50-60 sfm. Feed: 0.005-0.008 in. Oil or waterbase coolants will reduce thermal shock damage of carbide cutter teeth.
End Milling Not recommended , but C-2 grades may be successful on good setups. Use positive rake. Speed: 50-60 sfm. Feed: Same as high speed steel. Oil or water-base coolants will reduce thermal shock damage.
Drilling C-2 grade not recommended, but tipped drills may be successful on rigid setup if no great depth. The web must thinned to reduce thrust. Use 135 degree included angle on point. Gun drill can be used. Speed: 50 sfm. Oil or water-base coolant. Coolant-feed carbide tipped drills may be economical in some setups.
Reaming C-2 or C-3 grade: Tipped reamers recommended, solid carbide reamers require vary good setup. Tool geometry same as high speed steel. Speed: 50 sfm. Feed: Same as high speed steel.
Tapping Not recommended, machine threads, or roll-form them.
Electrical Discharge Machining The alloys can be easily cut using any conventional electrical discharge machining system (EDM) or wire (EDM).
5 M-40 series High Speed Steels include M-41 , M-42, M-43, M-44, M-45 and M-46 at the time of writing. Others may be added and should be equally suitable.

6 Oil coolant should be a premium quality, sulfochlorinated oil with extreme pressure additives. A viscosity at 100 degree F from 50 to 125 SSU.

7 Water-base coolant should be premium quality, sulfochlorinated water soluble oil or chemical emulsion with extreme pressure additives. Dilute with water to make 15:1 mix.

Table 18
Plasma Arc Cutting
Our alloys can be cut using any conventional plasma arc cutting system. The best arc quality is achieved using a mixture of argon and hydrogen gases. Nitrogen gas can be substituted for hydrogen gases, but the cut quality will deteriorate slightly. Shop air or any oxygen bearing gases should be avoided when plasma cutting these alloys.

MONEL® is a registered trademark of the INCO family of companies.

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