Alloy 20 Torx Screws
Alloy 20 Torx Screws, also known as Carpenter 20 and 20CB-3, offers a combination of nickel, chromium, molybdenum, and copper which provides good general corrosion resistance. Alloy 20 (2.4660) Torx Screws are best suited for mid-range corrosion use – better than steel alloys but not at the level of high performance nickel based alloys like Hastelloy C276. Alloy 20 is a nickel alloy that was specifically designed to withstand the harsh environment of hot sulfuric acid but also performs well in a variety of other acids. Alloy 20 Torx Screws are an ideal choice when you don’t need the corrosion resistance power and price-tag of high performance nickel alloys like Hastelloy C276; but you need something that will give you more protection than 316 stainless steel or even a Super Duplex 2507 stainless steel.
Good Mid-Range Corrosion Resistant Alloy
Mid-range corrosion resistant alloy
Decent mechanical strength to 1000°F
Alloy 20 chemistry and specifications
Alloy 20 sulfric acid performance
Datasheet for Alloy 20 Torx Screws
Corrosion Resistance
Alloy 20 Torx Screws provide good performance in hot sulfuric acid, specifically they offer good resistance to stress-corrosion cracking in boiling sulfuric acid at specific range of 20% to 40% concentration, as well as general sulfuric acid resistance. Alloy 20 (2.4660) Torx Screws offer solid acid protection and will perform better than Duplex or even Monel, but for high temperature and high concentration acids, you may need to look to Inconel or Hastelloy fasteners. In addition Alloy 20 Torx Screws also show useful resistance to phosphoric acid and nitric acid.
Key Corrosion Resistant Features:
Good sulfuric acid protection at 20% - 40%
Decent stress corrosion cracking, pitting and crevice corrosion resistance in chloride
Resonable general corrosion protection
Good intergranular corrosion resistance in the as-welded condition
Mechanical Properties
• Ultimate tensile strength: 80 ksi
• Yield strength: 35 ksi
• Density: 0.292 lb/in.3
• Electrical Resistivity (RT) 651 ohm-cir mil/ft
• Elongation: 30%
Temperature: In addition to their corrosion resistance, Alloy 20 Torx Screws also perform well at moderately high temperatures, with the ability to maintain their mechanical strength up to 1000°F.
Welding: Alloy 20 Torx Screws are stabilized with Columbium to minimize carbide precipitation during welding. In addition it offers intergranular corrosion resistance in the as-welded condition.
Applications
• Power plants rely on alloy 20 Torx Screws for flue-gas desulfurization
• Alloy 20 Torx Screws are used to connect heat exchangers, mixing tanks, metal cleaning equipment, pickling tanks and racks, and piping in mid-range corrosive chemcial processing environments.
• Alloy 20 Torx Screws help solve corrosion issues in food and dye production.
• Manufacturers of plastics and synthetic rubber also utilize alloy 20 Torx Screws.
Resources: Alloy 20 Torque Specs
Alloy 20 Fastener Types: Bolts, Nuts, Screws, Studs, Threaded Rods, Washers
Custom Availability
Diameter sizes: Standard #00 – 4” in diameter / Metric M1.2 – M100
Threads: UNC, UNF, UNJ, UNR, Rolled,Cut
Minimum Volume – Typically 10pcs, depending on size and stock
Custom to print
Alloy 20 Fastener Styles
| Alloy 20 Screws | 12 Point Screws Button Head Cap Screws Flat Head Screws Hex Head Cap Screws Pan Head Screws Security Screws Set Screws Socket Head Cap Screws Vented Screws | • DIN 603 / ISO 8677 • DIN 912 / ISO 4762 • DIN 913 / ISO 4026 • DIN 914 / ISO 4027 • DIN 915 / ISO 4028 • DIN 916 / ISO 4029 • DIN 921 • DIN 931 / ISO 4014 • DIN 933 / ISO 4017 • DIN 961 / ISO 8676 • DIN 965 / ISO 7046 • DIN 966 / ISO 7047 • DIN 7991 / ISO 10642 • DIN 7380 / ISO 7380 • DIN 84 / ISO 1207 • DIN 85 / ISO 1580 • DIN 34822 • DIN 34821 • DIN 7504 / ISO 15480 • DIN 7984 • DIN 963 / ISO 2009 |
| Alloy 20 Bolts | Hex Head Bolts Shoulder Bolts Wedge Anchor Bolts | • DIN 931
• DIN 933
• ISO 4014
• ISO 4017
• ISO 7370 |
| Alloy 20 Nuts | Hex Nuts Lock Nuts | • DIN 439 / ISO 4035
• DIN 934 / ISO 4032
• DIN 985 / ISO 7040
• DIN 986
• DIN 980 / ISO 7042 / ISO 19513
• DIN 6923 / ISO 4161 |
| Alloy 20 Studs/Rod | Studs Threaded Rod Weld Studs | • DIN 975
• DIN 976 |
| Alloy 20 Washers | Flat Washers Lock Washer | • DIN 125 / ISO 7089 / ISO 7090
• DIN 126 / ISO 7091
• DIN 127 / ISO 7090
• DIN 9021 / ISO 7093 |
| Alloy 20 Hose Clamps | Medium Duty Hose Clamps |
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Alloy 20 Screws
12 Point Screws | Alloy 20 12 point screws allow for higher torque to be applied than a socket head cap screw or head head bolt, however they are be less economical due to the complex head design. Available in 1/4" or larger sizes. | • IFI-115
• MIL SPEC
• DIN 34822
• DIN 34821 |
Button Head Cap Screws | Alloy 20 button head screws offer a wide clamping area and low profile. They are best for fastening material that is too thin to counter bore. | • ASME B18.3
• ASME 18.3.4M
• DIN 7380 / ISO 7380 |
Flat Head Screws | Alloy 20 flat head screws are most commonly offered in an 82° countersink angle, but can be customized to other angles from 60° -120° and are designed to be flush with the surface. Available in slotted and socket drivers. Phillips, 6-lobe, torx and tamperproof drivers in Alloy 20 flat head screws can be made require special manufacturing. | • ASME B18.3
• ASME B18.3.6
• DIN 963 / ISO 2009
• DIN 965 / ISO 7046
• DIN 7991 / ISO 10642 |
Hex Head Cap Screws | Alloy 20 hex head cap screws offer the added washer face to the bolt head which is lacking on a hex bolt and tighter dimensional tolerances. Ideal for a high clamping force applications with ease of access. Generally availabe in #2 - 1/2" sizes and metric sizes. | • ASME B18.6.3
• DIN 931 / ISO 4014
• DIN 933 / ISO 4017
• DIN 961 / ISO 8676 |
Pan Head Screws | Alloy 20 pan head screws offer a rounded top are best used for small diameter faster needs. Offered in slotted and they are ideal for low torque applications. | • ASME B18.6.3
• DIN 7985
• DIN 921
• DIN 85 / ISO 1580
• DIN 84 / ISO 1207
(cheese head)
• DIN 966 / ISO 7047
(raised counter sunk) |
Security Screws | Unique driver designs offer these Alloy 20 screws resistance to unwanted tampering or removal due to the fact that they cannot be removed using an ordinary driver. Alloy 20 security screws are available in several different drive styles, as well as custom per print. |
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Set Screws | Alloy 20 set screws are available in cup, cone, flat, dog and half-dog points. Set screws have no head and are equiped with a socket or slotted driver at one end. | • ASME B18.3
• DIN 913 / ISO 4026
• DIN 914 / ISO 4027
• DIN 915 / ISO 4028
• DIN 916 / ISO 4029 |
Socket Head Cap Screws | Alloy 20 socket head cap screws are ideal for limited access situations where there is little clearance around the screws. They offer a safe, reliable and economic solution. | • ASMET B18.3
• DIN 912 / ISO 4762
• DIN 7984 |
Vented Screws | Alloy 20 vented screws are best for vacuum environments because the hole drilled through its axis (from head through threads) allow gases and other contaminents to vent. Alloy 20 vented screws are available in any style. |
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Alloy 20 Bolts
Hex Head Bolts | Alloy 20 hex bolts are similar to hex head cap screws but without the added washer face. They are ideal for high clamping force applications with ease access. | • ASME B18.2.1
• DIN 931 / ISO 4014
• DIN 933 / ISO 4017 |
Shoulder Bolts | Alloy 20 shoulder bolts are made up of a head, shoulder and threaded segment. The smooth shoulder section allows for rotating parts. Typically available with socket drivers. | • ASME
• DIN 7379 / ISO 7379
• ISO 7370 |
Wedge Anchor Bolts | Alloy 20 wedge anchor bolts offer a safe secure fastening solution for attaching equipment and other materials to concrete in corrosive environments. |
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Alloy 20 Nuts
Hex Nuts | Alloy 20 hex nuts are available in a variety of styles including finished hex nuts, jam nuts and heavy hex nuts. | • ASME B18.16.3
• ASME B18.2.2
• DIN 439 / ISO 4035
• DIN 934 / ISO 4032
• DIN 986 |
Lock Nuts | Alloy 20 lock nuts are available in all metal and polymer insert styles. All-metal lock provide even load distribution and can be used at high temperatures. Polymer insert styles are more economical and are best for temperatures under than 350°F. | • ASME B18.16.3M
• DIN 980 / ISO 7042 /
ISO 19513
• DIN 6923 / ISO 4161
• DIN 985 / ISO 10511 /
ISO 7040 |
Alloy 20 Studs & Threaded Rods
Studs | Alloy 20 studs are fully threaded or partially threaded and made to custom lengths. | • ASME B18.31.2
• DIN 976 |
 Threaded Rod | Alloy 20 threaded rod or all thread are available in lengths greater than 1 foot. Minimum order quantity is a total of 6 feet of length. | • ASME B1.1
• DIN 975 |
Weld Studs | Alloy 20 weld studs are available in both arc or capacitor discharge (CD) styles. Weld studs provide an extremely secure fastening solution when one side of the stud needs to be permanently fix to a part and the other side with the threads accessible. |
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Alloy 20 Washers
Flat Washers | Alloy 20 washers are most commonly offered in SAE sizes, but also availabe in USS, oversized and custom sizes upon request. | • ASME 18.21.1
• SAE / USS
• DIN 125 / ISO 7089 /
ISO 7090
• DIN 126 / ISO 7091 |
Lock Washers | Alloy 20 lock washers are offered as split lock washers. Belleville spring lock washers can also be made upon request. | • ASME B18.21.1
• DIN 127 / ISO 7090
• DIN 6796 / ISO 10690
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Alloy 20 Chemistry & Specifications (2.4660)
Alloy 20 Specifications: UNS N08020, ASME SA240, , ASME SB366, ASME SB462, ASME SB463, ASME SB464, ASME SB473, ASME SB729, ASTM A240, ASTM B366, ASTM B463, ASTM B464, ASTM B473, ASTM B729, ASTM BB462, ANSI/ASTM A555-79, EN 2.4660, , Werkstoff 2.4660, CN7M, DIN 2.4660
| Alloy 20 | Ni | Cr | Mo | Mn | Cu | Si | C | S | P | Cb+Ta | Fe |
| Min | 32.5 | 19.0 | 2.0 | - | 3.0 | - | - | - | - | 8.0XC1.0 | - |
| Max | 35.0 | 21.0 | 3.0 | 2.0 | 4.0 | 1.0 | 0.1 | 0.0 | 0.0 | - | Balance |
Threaded Rod
Alloy 20 Fasteners
