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

• Excellent resistance to hydrofluoric acid
• Excellent resistance to sea water for marine applications
• High strength metal with good toughness at high temperatures
• In-depth information on grades 400 and K500
• Datasheets available for Monel 400 and Monel K500
• Monel hex head cap screw features and benefits

Monel(R) hex head cap screws, like Monel 400 and K500, are made from a nickel-copper alloy and exhibit high strength, toughness and good corrosion resistance over a wide temperature range. An outstanding characteristic of Monel screws is that they offer exceptional resistance to hydrofluoric acid, a particularly tough acid to deal with, in all concentrations up to the boiling point. For hydrofluoric acid applications Monel hex head cap screws are perhaps the most resistant of all commonly used specialty alloys.

Monel alloy 400 & K500 screws also exhibit excellent corrosion resistance in marine applications and have reasonable corrosion resistance to sulfuric and hydrochloric acids under reducing conditions.

Because of these characteristics, Monel hex head cap screws are often found in marine and chemical processing applications.

The most common grades of Monel nickel alloy 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.

Resources: Monel Torque Spec, Flange Dimensions, Flange Bolting Chart, Monel 400, Monel K500

Screw Types: 12 Point Screws, Button Head Cap Screws, Flat Head Screws, Hex Cap Screws, Pan Head Screws, Set Screws, Socket Head Cap Screws, Tamper Resistant Security Screws, Torx Screws

Monel Hex Head Cap Screw Features and Benefits

It is important to differentiate between a Monel hex head cap screw and hex head bolt. 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

Monel Hex Head Cap Screw Advantages  

The most important feature of a Monel hex head cap screws is that it has a larger bearing surface area which provide better clamping pressure than other type of fastener such as a socket head cap screw. Additionally, since debris build up is less of an issue with this style of fastener verses a socket head cap screw, they are ideal of dirty applications where particles could clog up a socket. Though Monel socket heads are typically used for tight access applications, hex heads can be a better choice when there is only side clearance available for tightening. 

Common Grades of Monel Screws

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), VdT"UV 263 (Sheet, Plate, Bar, and Tubing), QQ-N-281 (Plate, Sheet, Strip, Bar, Rod, Wire, and Forgings), Werkstoff 2.4360

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

 Mechanical Properties of Monel

Monel 400 Corrosion Data