A Ni-Cu alloy with high strength and good corrosion resistance

Strength & Saltwater Resistance
Monel® socket head cap screws are made from a nickel-copper alloy that exhibits high strength, toughness and good corrosion resistance. Renowned for the saltwater corrosion resistance, Monel is the go-to material by the navy. It is often used in many other marine applications for its combination of high strength and seawater resistance. Monel screws are even resistant to rapid moving seawater and will last many years in saltwater conditions.
 
Strength and Toughness from Cryogenic to 1000°F
Monel socket head cap screws offer excellent mechanical properties over a wide temperature range from cryogenic up to 1000°F. In US Navy tear tests at temperatures as low as -320°F, Monel 400 has displayed excellent ductility and toughness. In fact, it has shown little decrease in impact resistance when tested on plates at liquid-hydrogen and liquid-helium temperatures.
 
Monel K500 is an age hardened alloy, known for extreme strength even at high temps. But it is also excellent for cryogenic service. Monel K500's tensile and yield strength increase - with little or no change to ductility and toughness - even at the temperature of liquid hydrogen.
 
Excellent Resistance to Hydrofluoric Acid
One of the most outstanding characteristics of Monel socket head cap screws is that they offer exceptional resistance to hydrofluoric acid (HF), a particularly tough acid to deal with, in all concentrations up to the boiling point. For hydrofluoric acid applications Monel screws are perhaps the most resistant of all commonly used specialty alloys.

The most common grades of Monel screws are Monel 400 and Monel K500 . Gain more insight on these two grades by accessing our Monel 400 and K500 overviews or by contacting our engineering experts.

ResourcesMonel Torque SpecMonel 400Monel K500

Bolt Types Available: Hex BoltsShoulder Bolts

 


Monel Hex Head Bolt Features and Benefits

It is important to differentiate between a Monel hex head bolt and hex head cap screw. Often people assume they are the same, but they are actually very different fasteners in terms of how they are manufactured, as well as from an application perspective. Regardless of your choice, Monel hex heads offer strong, stable joints because of their large head service. 

The Hex Comparison

Hex Head Bolts

Hex Head Cap Screw
  • Hex bolts have a flat end and lack the washer face under the head.
  • Appropriate for when mechanical properties are more important than dimensional tolerances.
  • Features flat washer facing under the bolt head.
  • Also called a finished hex bolt. 
  • Has tighter tolerances on the body dimensions. 
  • Best used for precise applications where tight tolerances on the body dimensions are required. 

 


Common Grades of Monel Bolts

Monel 400 

Monel 400, UNS N04400 (QQ-N-281), is a nickel-copper alloy with high strength and excellent corrosion resistance in a range of media including sea water, hydrofluoric acid, sulfuric acid, and alkalies. Monel 400 is commonly in marine engineering, chemical and hydrocarbon processing applications.

Monel 400 Specifications: BS3075NA13 (Wire), BS3076NA13 (Bar), ASTM B 164 (Rod, Bar, and Wire), ASTM B 564 (Forgings), ASME SB 164 (Rod, Bar, and Wire), ASME SB 564 (Forgings), AECMA PrEN 2305 (Wire for Rivets), SAE AMS 4675 (Bars and Forgings), SAE AMS 4730 (Wire), SAE AMS 4731 (Wire and Ribbon), DIN 17752 (Rod and Bar), DIN 17753 (Wire), DIN 17754 (Forgings), VdTÜV 263 (Sheet, Plate, Bar, and Tubing), QQ-N-281 (Plate, Sheet, Strip, Bar, Rod, Wire, and Forgings), Werkstoff 2.4360

Monel 400 Chemistry

Monel K500 

Monel K500, UNS N05500 (QQ-N-286),  is a precipitation-hardenable nickel-copper alloy that combines the corrosion resistance of Monel alloy 400 with greater strength (over 2x as strong) and hardness. It also has low permeability and is nonmagnetic to temperatures as low as -150°F (-101°C). 

Monel K500 Specifications: BS3075NA18 (Wire), BS3076NA18 (Rod and Bar), ASTM B 865 (Rod and Bar), DIN 17752 (Rod and Bar), DIN 17753 (Wire), DIN 17754 (Forgings), QQ-N-286 (Rod, Bar, Wire, and Forgings), SAE AMS 4676 (Rod and Bar), ASME Code Case 1192 (Rod and Bar), ISO 9723 (Bar), ISO 9724 (Wire), ISO 9725 (Forgings), Werkstoff 2.4375

Monel K500 Chemistry

 


 Mechanical Properties of Monel

Monel 400 Tensile Curves         Monel alloy K500 Tensile Data

Tensile Chart Updated 9 12 18   Monel K500 Tensile Data


 

Monel 400 Corrosion Data

Monel HF vs Nickel Alloys revised

Monel 400 HF IsoCorrosion Curve

 

Not sure what material is best for your application?

Contact an Expert

Use Our Material Selector

 

Request a Quote / Order

Call: 888-393-4517 or Submit a Request
Questions?

Our material experts are ready to help guide you through your specific application.

Contact an Expert