A286 Lock Nuts

A286 / Alloy 660 for excellent high temperature oxidation resistance

• Good material for high temperature oxidation resistance
• Maintains high strength at elevated temperatures
• Specifications & heat treatment options
• Lock nut specifications
• ASTM A453 Grade 660
• A286 chemistry
• Datasheet for A286
• A286 lock nut availability

A286 nuts, also known as Alloy 660 nuts are stainless steel alloy which contains iron, nickel and chromium. A286 lock nuts are known for their high strength, creep resistance and oxidation resistance at elevated temperatures once age hardened.  As a result, A286 nuts provide high levels of strength from room temperature up to about 1300°F (700°C).

A286 lock nuts are also mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1500°F (815°C) in conditions that would typically be found in high temperature exhaust streams.

Applications

Because of the properties of Alloy 660 / A286, these lock nuts are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications. In addition, A286 / Alloy 660 is also non-magnetic and finds a niche in non-magnetic cryogenic equipment. In addition, we offer bolts and fasteners per ASTM A453 Grade 660. This specification ensures tensile and rupture properties for the most critical high temperature applications.

Resources: A286 Torque Specs

A286 / Alloy 660 Locknut Features and Beneifts

An A286 locknut resists loosening from vibrations and torque. One of the most common styles is a prevailing torque locknut. This kind of A286 / Alloy 660 locknut has a prevailing torque feature which deforms elastically, preventing it from freely spinning like a standard nut.

The two most common and reliable forms of prevailing torque locknuts are the flexloc style and the polymer insert lock nut. An Alloy 660 / A286 flexloc nut is all-metal in composition with a segmented collar that creates six “locking fingers,” that act as a spring. A286 polymer insert lock nuts are often referred to as nylon insert locknuts, although various high performance polymers can be used for the screw threads to “bite into.” Both flexlock and polymer insert locknuts are available in both hexagonal and 12 point configurations.

All Metal Flexloc Lock Nut	Polymer/Nylon Insert Lock Nut
Can be used at high temperatures Distributes load evenly due to the fact that it is manufactured as one solid piece. Is THE most reliable all-metal self-locking nut. As it is all metal, it is best for high temperature or corrosive applications One of the only all-metal lock nuts that is certified to 15 cycles of prevailing torque – which is military standard.	Overall the most reliable locknut, with the only limitation of application temperature Best for low temp applications, typically less than 350°F Various polymers inserts available (Nylon, Vespel, PVDF, etc.) for higher temp. or corrosive applications. Excellent reusability – can reliably be re-used 15 times Eliminates galling and cold-welding common with exotic alloys

Other all metal lock nuts available include the A286 / Alloy 660 stover and elliptical styles. Though these styles are often a cheaper initial cost, they are less reliable than the flexloc style. As these styles delivering less prevailing torque cycles and often result in more failures, the flexloc style is a better investment for both reliability and cost savings.

Lock Nut Specifications

A286 Lock Nut Availability

A286 lock nuts are available in these sizes. Please contact us for price and lead times.

Lock Nut Sizes
•  #00 - 10"
•  M1.2 - M250

ASTM A453 Grade 660

Material specification ASTM A453 Grade 660 applies to bolts, studs, studs and other fasteners. It ensures fasteners meet strength standards for use in high temperature bolting applications. ASTM A453 Grade 660 is classified into 4 property classes / heat treatments: A, B, C & D, each designated with different tensile and stress rupture properties. The most common of the ASTM 453 classes are class A or D. The grades A, B and C all have the same minimum tensile strength and minimum yield strength of 130ksi and 85ksi respectively. However grade D has a significantly better yield with a min tensile of 130ksi and a min yield of 105ksi.

Additional A286 / Alloy 660 Specifications, Cold Working & Heat Treatments

AMS A286 / Alloy 660 Heat Treatments

By AMS numbers, the most common for A286 / Alloy 660 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B).

A286 / Alloy 660 Cold Worked Fasteners

For additional strength, A286 could be aged and cold worked to achieve a min ultimate tensile strength of 160ksi upon request.

Additional Specifications

UNS S66286, ASTM A453, AMS 5525, AMS 5726, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, Werkstoff 1.4980, ASTM F2281

A286 / Alloy 660 Chemistry

Mechanical Properties

A-286 Weld Neck Flanges

 A Fe-Ni-Cr alloy with excellent high temperature oxidation resistance

• Good material for high temperature oxidation resistance
• Maintains high strength at elevated temperatures
• A286 Chemistry, specs, and heat treatments
• Weld neck flange features and benefits

A-286 weld neck flanges are known for their high strength, creep resistance and oxidation resistance at elevated temperatures. This iron-nickel-chromium alloy (once age-hardened) provides A-286 weld neck flanges with high levels of strength from room temperature up to about 1300°F (700°C).

A-286 weld neck flanges are mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1300°F (700°C) in conditions that would typically be found in high temperature exhaust streams.

Because of these properties, A-286 weld neck flanges are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications.

Resources: A-286 Torque Specs, Flange Dimensions, Flange Bolting Chart

Flange Types Available: Blind Flanges, Lap Joint Flanges, Slip On Flanges, Socket Weld Flanges, Threaded Flanges, Weld Neck Flanges

A-286 Chemistry, Specifications & Heat Treatments

A-286 Heat Treatments:  There are several heat treatment combinations for A-286 all with slight variations in performance. They can be specified via an AMS number or a 660 Class: A, B, C or D,  with most common specified as class A or D.   The A-286 grades A, B and C all have the same min tensile strength and min yield strength of 130ksi and 85ksi respectively. However grade D is significantly better yield with a min tensile of 130ksi and a min yield of 105ksi. 

By AMS numbers, the most common for A-286 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B). 

A-286 Specifications: AMS 5525, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, UNS S66286, Werkstoff 1.4980

Mechanical Properties

A286 Weld Neck Flange Features & Benefits

A286 weld neck flanges are best for hazardous, high pressure applications. Weld neck flanges are easily identified by their long tapered neck. The inside of the flange is bored to match the inside diameter of the pipe in order to ensure there is no restriction in flow and also to prevent turbulence at the joint. The tapered neck provides thicker metal at the flange joint, while the neck narrows down gradually to meet the pipe where it is butt welded to the pipe. This design helps to transfer stress from the flange to the pipe, as well as diminish stress concentration at the base of the flange connection.

A286 weld neck flanges are ideal for critical applications involving high pressure, sub-zero and elevated temperatures, as well as in conditions where fluctuations cause pipe expansion/contraction.

Key Feature: Ideal for high presure applications.

Weld Neck Flange Advantages

• Ability to withstand high pressure – since pipe is welded to the neck of the flange, stress is transferred to the pipe.
• The beveled end that, when connected to a pipe, creates a trough for a strong weld.
• Most versatile flange in the ASME stable of flanges.

Weld Neck Flange Disadvantages

• More advanced welding skill is needed for installation. The inside weld must be smooth to reduce friction and the outside weld must meet code criteria.

Uses

• Severe conditions that include high-pressure, high-cyclic and hazardous fluid applications.
• Fitting-to-fitting fabrication where the flange is welded directly to a fitting, such as an elbow, without the need for a short piece of pipe, as would be required with a slip-on flange.

A-286 Slip On Flanges

 A Fe-Ni-Cr alloy with excellent high temperature oxidation resistance

• Good material for high temperature oxidation resistance
• Maintains high strength at elevated temperatures
• A286 Chemistry, specs, and heat treatments
• Slip on flange features and benefits

A-286 slip on flanges are known for their high strength, creep resistance and oxidation resistance at elevated temperatures. This iron-nickel-chromium alloy (once age-hardened) provides A-286 slip on flanges with high levels of strength from room temperature up to about 1300°F (700°C).

A-286 slip on flanges are mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1300°F (700°C) in conditions that would typically be found in high temperature exhaust streams.

Because of these properties, A-286 slip on flanges are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications.

Resources: A-286 Torque Specs, Flange Dimensions, Flange Bolting Chart

Flange Types Available: Blind Flanges, Lap Joint Flanges, Slip On Flanges, Socket Weld Flanges, Threaded Flanges, Weld Neck Flanges

A-286 Chemistry, Specifications & Heat Treatments

A-286 Heat Treatments:  There are several heat treatment combinations for A-286 all with slight variations in performance. They can be specified via an AMS number or a 660 Class: A, B, C or D,  with most common specified as class A or D.   The A-286 grades A, B and C all have the same min tensile strength and min yield strength of 130ksi and 85ksi respectively. However grade D is significantly better yield with a min tensile of 130ksi and a min yield of 105ksi. 

By AMS numbers, the most common for A-286 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B). 

A-286 Specifications: AMS 5525, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, UNS S66286, Werkstoff 1.4980

Mechanical Properties

A286 Slip on Flange Features & Benefits

A286 slip on flanges are similar to the socket weld flange but without the socket shoulder. When using a socket weld flange, the pipe rests against this internal shoulder. Since a slip on flange does not have shoulder, the pipe can slide completely through the flange hub and is free to spin. 

Advantages

• Typically lower in price than weld-neck flange, yet welding costs can be more.
• There is a reduced need to cut the pipe length accurately, making it easier to install.
• The slip on flange is free to spin on the pipe for easy bolt alignment.

Disadvantages

• They require two fillet welds: one fillet weld at the hub of the flange and a second weld at the inside diameter of the flange near the flange face.
• Though they can be used for high temperature and pressure applications, they typically are not as other flange types give a more secure joint.

A286 Shoulder Bolts

A286 / Alloy 660 for excellent high temperature oxidation resistance

• Good material for high temperature oxidation resistance
• Maintains high strength at elevated temperatures
• Specs & heat treatments
• ASTM A453 Grade 660
• A286 chemistry
• Datasheet for A286

A286 bolts, also known as Alloy 660 bolts are stainless steel alloy which contains iron, nickel and chromium. A286 shoulder bolts are known for their high strength, creep resistance and oxidation resistance at elevated temperatures once age hardened.  As a result, A286 bolts provide high levels of strength from room temperature up to about 1300°F (700°C).

A286 shoulder bolts are also mildly corrosion resistant. While they should not be used for strong acid environments, they provide excellent oxidation resistance up to 1500°F (815°C) in conditions that would typically be found in high temperature exhaust streams.

Applications

Because of the properties of Alloy 660 / A286  these shoulder bolts are often found in high temperature engine, manifold, exhaust and turbine applications as well as off-shore oil & gas applications. In addition, A286 / Alloy 660 is also non-magnetic and finds a niche in non-magnetic cryogenic equipment.

 Resources: A286 Torque Specs

Bolt Types Available: Hex Bolts, Shoulder Bolts

A286 / Alloy 660 Shoulder Bolt Features and Benefits

A286 shoulder bolts, also called stripper bolts are a unique fastener with three main parts: head, shoulder, and thread. The head has the largest diameter and is where the torque is applied, typically with a socket driver. The shoulder is smooth and unthreaded, and has a set diameter and length. The shoulder’s role is to act as a shaft or dowel for rotating parts, axles for rolling parts, guides for sliding elements, and pivot points. The final part of an A286 / Alloy 660 shoulder bolt is the threaded shaft. The threaded portion of a shoulder bolt has a major diameter slightly smaller than the shoulder diameter.

ASTM A453 Grade 660

Material specification ASTM A453 Grade 660 applies to bolts, studs, studs and other fasteners. It ensures fasteners meet strength standards for use in high temperature bolting applications. ASTM A453 Grade 660 is classified into 4 property classes / heat treatments: A, B, C & D, each designated with different tensile and stress rupture properties. The most common of the ASTM 453 classes are class A or D. The grades A, B and C all have the same minimum tensile strength and minimum yield strength of 130ksi and 85ksi respectively. However grade D has a significantly better yield with a min tensile of 130ksi and a min yield of 105ksi.

Additional A286 / Alloy 660 Specifications, Cold Working & Heat Treatments

AMS A286 / Alloy 660 Heat Treatments

By AMS numbers, the most common for A286 / Alloy 660 is AMS 5737 (same as Grade A) and then AMS 5732 (same as Grade B).

A286 / Alloy 660 Cold Worked Fasteners

For additional strength, A286 could be aged and cold worked to achieve a min ultimate tensile strength of 160ksi upon request.

Additional Specifications

UNS S66286, ASTM A453, AMS 5525, AMS 5726, AMS 5732, AMS 5737, AMS 5804, EN 1.4980, GE B50T1181, GE B50T12, GE B50T81, Werkstoff 1.4980, ASTM F2281

A286 / Alloy 660 Chemistry

Mechanical Properties