Inconel® 686 is a high-performance nickel-based alloy engineered for exceptional corrosion resistance in the harshest environments, making it a premier choice for critical components in the fastener industry. With a unique blend of nickel, chromium, molybdenum, and Tungsten, Inconel® 686 offers outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking—qualities essential for fasteners exposed to aggressive chemicals, seawater, and high-temperature operations. Whether used in chemical processing, marine, or flue gas desulfurization systems, fasteners made from Inconel 686 deliver long-term reliability and mechanical strength. Contact Nickel Systems today to request a quote and learn how our Inconel® 686 fasteners can meet your demanding application needs.
Get our technical data and information below. Download our Inconel 686 Technical Data Sheet here.
Inconel® 686 Specifications | |||||
NACE | ASTM | ASME | DIN | SAE/AMS | |
All Forms | RP0294 | ||||
Rod, Bar, Wire, & Forging Stock | RP0294 | B462, B564, B574 | SB564, B574 | 17752, 17753, 17754 | |
Plate, Sheet, & Strip | RP0294 | B575, B906 | SB575, SB906 | 17750 | |
Pipe & Tube | RP0294 | B163, B619, B622, B626, B751, B775, B829, | SB163, SB619, SB622, SB626, SB751, SB775, SB829 | 17751 | |
Fasteners | RP0294 | F467(M), F468(M) | J2295, J2271, J2655, J2280, J2484, J2485 | ||
Composition | RP0294 | 17744 | |||
Inconel® 686 Chemical Composition | ||
Element | Percent Composition | Description |
Nickel (Ni) | ~ 56.27 % | Balance |
Chromium (Cr) | 19.0 - 23.0 % | Range |
Molybdenum (Mo) | 15.0 - 17.0 % | Range |
Tungsten (W) | 3.0 - 4.4 % | Range |
Titanium (Ti) | 0.02 - 0.25 % | Range |
Iron (Fe) | 2.0 % | Max |
Carbon (C) | 0.01 % | Max |
Manganese (Mn) | 0.75 % | Max |
Sulfur (S) | 0.02 % | Max |
Silicon (Si) | 0.08 % | Max |
Phosphorus (P) | 0.04 % | Max |
Inconel® 686 Physical Properties | |
Density | 0.315 lb/in³ |
8.73 g/cm³ | |
Melting Range | 2,440 - 2,516 ℉ |
1,338 - 1,380 ℃ | |
Electrical Resistivity | 744.4 ohm●circ mil/ft |
1.237 μΩ●m | |
Permeability at 200 oersted (15.9 KA/M) | 1.0001 |
Inconel 686 Physical Properties | |||
Temperature | Young's Modulus | Shear Modulus | Poisson's Ratio |
℉ | 10³ ksi | 10³ ksi | |
70 | 30.0 | 11.1 | 0.35 |
200 | 29.7 | 10.9 | 0.36 |
400 | 28.5 | 10.5 | 0.36 |
600 | 28.0 | 10.2 | 0.37 |
800 | 26.9 | 9.9 | 0.36 |
1,000 | 26.0 | 9.5 | 0.37 |
1,200 | 24.6 | 9.1 | 0.35 |
Temperature | Young's Modulus | Shear Modulus | Poisson's Ratio |
℃ | GPa | GPa | |
20 | 207 | 77 | 0.34 |
100 | 205 | 75 | 0.37 |
200 | 197 | 72 | 0.37 |
300 | 193 | 70 | 0.38 |
400 | 185 | 69 | 0.34 |
500 | 183 | 67 | 0.37 |
600 | 173 | 65 | 0.33 |
700 | 165 | 61 | 0.35 |
Inconel® 686 Mechanical Properties | ||||
Product Form | Thickness or Diameter | Tensile Strength | Yield Strength (0.2% Offset) | Elongation |
Plate | 0.500 in / 12.7 mm | 104.7 ksi / 722 MPa | 52.8 ksi / 364 MPa | 71 % |
Plate | 0.250 in / 6.35 mm | 106.3 ksi / 733 MPa | 57.9 ksi / 399 MPa | 68 % |
Sheet | 0.125 in / 3.18 mm | 116.5 ksi / 803 MPa | 61.1 ksi / 421 MPa | 59 % |
Sheet | 0.062 in / 1.57 mm | 123.0 ksi / 848 MPa | 59.2 ksi / 408 MPa | 59 % |
Rod | 1.50 in / 38.1 mm | 117.5 ksi / 810 MPa | 52.1 ksi / 359 MPa | 56 % |
Inconel® 686 Thermal and Electrical Properties | |||
Temperature | Specific Heat | Coefficient of Expansion | Electrical Resistivity |
℉ | Btu/lb●℉ | 10^(-6) in/in●℉ | ohm●circ mil/ft |
0 | 0.087 | - | - |
70 | 0.089 | - | 744.4 |
200 | 0.092 | 6.67 | 749.2 |
400 | 0.098 | 6.81 | 756.7 |
600 | 0.104 | 7.00 | 760.9 |
800 | 0.110 | 7.17 | 765.6 |
1,000 | 0.116 | 7.25 | 779.8 |
1,200 | 0.122 | 7.49 | 776.1 |
Temperature | Specific Heat | Coefficient of Expansion | Electrical Resistivity |
℃ | J/kg●℃ | μm/m●℃ | μΩ●cm |
-15 | 364 | - | - |
20 | 373 | - | 123.7 |
100 | 389 | 11.97 | 24.6 |
200 | 410 | 12.22 | 125.7 |
300 | 431 | 12.56 | 126.3 |
400 | 456 | 12.87 | 127.2 |
500 | 477 | 13.01 | 128.9 |
600 | 498 | 13.18 | 129.5 |
700 | 519 | - | 127.9 |
Inconel 686 Thermal and Electrical Properties | |||
Temperature | Thermal Conductivity | Temperature | Thermal Conductivity |
℉ | Btu●in/hr●ft²●℉ | ℃ | W/cm●K |
77 | 68.09 | 25 | 0.098 |
212 | 76.59 | 100 | 0.110 |
392 | 88.54 | 200 | 0.128 |
572 | 102.61 | 300 | 0.148 |
752 | 115.09 | 400 | 0.166 |
932 | 129.27 | 500 | 0.186 |
1,112 | 148.47 | 600 | 0.214 |
1,292 | 163.32 | 700 | 0.235 |
1,472 | 175.58 | 800 | 0.253 |
1,652 | 183.09 | 900 | 0.264 |
1,832 | 205.35 | 1,000 | 0.296 |
2,012 | 219.24 | 1,100 | 0.316 |
2,102 | 226.06 | 1,150 | 0.326 |
Inconel 686 High Temperature Mechanical Properties | |||
Temperature | Tensile Strength | Yield Strength (0.2% Offset) | Elongation |
75 ℉ / 24 ℃ | 107.3 ksi / 740 MPa | 57.5 ksi / 396 MPa | 60 % |
200 ℉ / 93 ℃ | 100.2 ksi / 691 MPa | 46.8 ksi / 323 MPa | 69 % |
400 ℉ / 204 ℃ | 92.1 ksi / 635 MPa | 42.1 ksi / 290 MPa | 67 % |
600 ℉ / 316 ℃ | 87.3 ksi / 602 MPa | 41.7 ksi / 288 MPa | 60 % |
800 ℉ / 427 ℃ | 82.6 ksi / 570 MPa | 32.5 ksi / 224 MPa | 69 % |
1,000 ℉ / 538 ℃ | 79.1 ksi / 545 MPa | 37.9 ksi / 261 MPa | 61 % |
These values are from tests with an average of three heats, 0.25 in plate. | |||
Below is a chart showing the effect of cold working at room temperature on mechanical properties:
Inconel 686 is a Nickel-Chromium-Molybdenum-Tungsten alloy. It is known for its high corrosion resistance and strength.
Here are several other names:
Check out Inconel® 686 chemical composition in this pie chart:
Inconel® 686 is renowned for its exceptionally broad corrosion resistance, especially in extreme environments.
Inconel® 686 offers outstanding resistance to uniform corrosion in both oxidizing and reducing environments. These include nitric, sulfuric, hydrochloric acid, seawater, and brine. This includes high-temperature environments such as chemical process plants and waste treatment.
Inconel® 686 exhibits superior pitting resistance. It out preforms both Inconel® 625 and Hastelloy® C-276 in standardized ASTM G48 pitting tests. This is due to its high chromium and molybdenum content. Inconel® 686 also delays onset of crevice corrosion better than other high nickel alloys.
Corrosion Comparison Inconel 625, Hastelloy C276, & Inconel 686 | |||
Corrosion Type | Inconel® 686 | ||
Uniform Corrosion | Excellent | Excellent | Superior |
Pitting Corrosion | Good-Excellent | Excellent | Best-in-class |
Crevice Corrosion | Good | Excellent | Superior |
Stress Corrosion Cracking | Very Good | Excellent | Exceptional |
Oxidizing Acids | Moderate | Good | Excellent |
Reducing Acids | Good | Excellent | Superior |
Mixed Acid Environments | Moderate-Good | Excellent | Excellent |
Inconel® 686 has excellent resistance against to stress cracking especially in chloride and caustic environments and in acidic oxidizing mixtures like nitric-sulfuric acid blends. It is also resistant at elevated temperatures above 150℃ where many alloys fail.
Inconel® 686 resists galvanic corrosion being a more noble material. However, it may cause galvanic corrosion when joined with carbon, steel, and aluminum materials.
Inconel® 686 resists intergranular corrosion in both normal and high temperature conditions. It is susceptible to fretting corrosion. Consider surface treatments or and coatings.
For more information check out our blog discussing the different types of corrosion.
These applications & industries use Inconel® 686 fasteners.
Inconel® 686 fasteners are used by chemical processing plants in reactor flange joints, pump and heat exchanger covers, and high-pressure pipe unions. These include heavy hex bolts, heavy hex nuts, and flat washers.
Pollution control systems use Inconel® 686 fasteners in their FGD absorber towers, acid gas scrubbers, and incinerator flue ducting. These fasteners include socket head cap screws, wedge lock washers, and U-bolts.
The oil and gas industries use Inconel® 686 stud bolts, socket shoulder screws, thread rods, and lock nuts, and washers in subsea manifold flanges, riser connector systems, and subsea Christmas tree valve bolts.
Looking for reliable supply and technical support? Contact Nickel Systems today for a customized quote on Inconel® 686 fasteners. Our team is ready to assist with pricing, certifications, and lead time information tailored to your project needs. Reach out by clicking on the link or calling to speak with a corrosion materials specialist.
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