Nickel alloy / Controlled expansion / DIN 17745
1.3922 Forgings: Ni48 Controlled-Expansion Alloy
Also known as Ni48, Alloy 48, NILO 48, Pernifer 48,
Invar 48, Glass Seal 48, SUPRA 50
UNS K94800 / ASTM F30 / DIN 17745 / W.-Nr. 1.3922, 1.3926, 1.3927 / AFNOR NF A54-301
1.3922 is the German material number for Ni48, a nickel-iron controlled-expansion alloy with nominally 48 % nickel and the balance iron. Its mean coefficient of thermal expansion is about 8.5 x 10⁻⁶/K from 20 °C to 100 °C, which matches soft lead and soda-lime glass. That is why the alloy is used for glass-to-metal seals and for industrial thermostats working up to 450 °C (840 °F). It is covered by DIN 17745, UNS K94800 and ASTM F30, and is also sold as NILO 48, Pernifer 48 and Alloy 48.
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. We produce 1.3922 as forged rings, seamless rolled rings, flanges, round bars, discs, shafts, sleeves, bushings, tubes and tube sheets, all made to customer drawing. Parts are supplied annealed and ultrasonically tested, with EN 10204 3.1 or 3.2 certification.
1.3922 at a glance
- Nominal nickel
- 48 %
- Balance
- Iron
- Mean CTE 20-100 °C
- 8.5 x10⁻⁶/K
- Max service temp.
- 450 °C
- Density
- 8.2 g/cm³
- Melting point
- 1450 °C
- UNS number
- K94800
- Delivery condition
- Annealed
Typical published values for Ni48 type controlled-expansion alloy, given for material selection. Values for a specific order are confirmed on the mill certificate supplied with the forgings.
Why 1.3922 seals to glass
A glass-to-metal seal fails when the two materials shrink at different rates as they cool. 1.3922 is not a low-expansion alloy like Invar 36. Its expansion coefficient is relatively high, but it was set to follow the expansion of soft lead and soda-lime glass, so the seal cools without residual stress.
| Invar 36 (1.3912) | 1.5 | |
|---|---|---|
| Alloy 42 (1.3917) | 5.3 | |
| 1.3922 / Ni48 | 8.5 | |
| Soda-lime glass | 9.0 | |
| Carbon steel | 11.7 | |
| 304 stainless | 17.3 | |
Comparison values are typical figures for material selection, not specification limits. 1.3922 sits within about 0.5 x 10⁻⁶/K of soda-lime glass, which is why it is specified for lamp bulbs, vacuum devices and hermetic electronic packages. The alloy also has a high inflection point near 460 °C, so expansion stays predictable across the thermostat working range.
1.3922 equivalent grades and specifications
1.3922 appears under a different name in most national standards and mill catalogues. The table below lists the designations buyers most often send us on drawings and enquiries.
| System or origin | Designation | Notes |
|---|---|---|
| German Werkstoff-Nr. | 1.3922 | Grade Ni48 under DIN 17745 |
| German, related numbers | 1.3926, 1.3927 | Same 48 % Ni family, different purity and form classes |
| UNS | K94800 | United States unified numbering |
| ASTM | ASTM F30 | Fe-Ni sealing alloys: sheet, strip, rod, bar, tube, wire |
| DIN | DIN 17745 | Wrought nickel-iron alloys |
| AFNOR, France | NF A54-301 | French national standard |
| Trade names | NILO 48, Pernifer 48, Glass Seal 48, Invar 48, SUPRA 50 | Commercial designations for the same 48 % Ni alloy |
| Common shorthand | Alloy 48, Ni48, NiFe48 | Used in purchasing documents |
If your drawing shows a designation not listed here, send it with your enquiry and we will confirm whether 1.3922 meets it before quoting.
Chemical composition of 1.3922
| Element | Symbol | Weight % |
|---|---|---|
| Nickel | Ni | 48.0 nominal |
| Chromium | Cr | 0.10 max |
| Manganese | Mn | 0.80 max |
| Silicon | Si | 0.30 max |
| Carbon | C | 0.05 max |
| Phosphorus | P | 0.025 max |
| Sulfur | S | 0.025 max |
| Iron | Fe | Balance |
Nickel content controls the expansion behaviour, so it is held to a close range on every heat. Our 1.3922 forging stock is melted by EAF and VOD and remelted by ESR, which keeps sulfur and phosphorus low and gives a clean, homogeneous structure.
Mechanical properties of 1.3922
| Condition | Tensile strength (psi) | Tensile strength (MPa) |
|---|---|---|
| Annealed | 85,000 max | 586 max |
| 1/4 hard | 90,000 to 115,000 | 620 to 793 |
| 1/2 hard | 105,000 to 125,000 | 724 to 862 |
| Hard | 120,000 min | 827 min |
Forgings are normally supplied annealed. Retained cold work distorts the expansion coefficient, so material intended for a glass seal or a thermostat should be used in the annealed condition.
Physical properties
| Property | Value |
|---|---|
| Density | 8.2 g/cm³ (0.298 lb/in³) |
| Melting point | 1450 °C (2640 °F) |
| Curie temperature | 471 °C (880 °F) |
| Inflection point | 460 °C |
| Modulus of elasticity | 160 GPa (23.2 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 16.7 W/m·K |
| Electrical resistivity at 20 °C | 47 µΩ·cm |
| Mean CTE 20-100 °C | 8.5 x 10⁻⁶/K |
| Mean CTE 30-300 °C | 8.8 x 10⁻⁶/K |
| Mean CTE 30-500 °C | 9.4 x 10⁻⁶/K |
Published typical values for the Ni48 alloy family, given for design and material selection. Actual results for a delivered lot appear on the EN 10204 certificate.
1.3922 forged products we supply
All items below are open-die forged or ring rolled to your drawing. There are no standard catalogue sizes and no tooling charge.
Rings and rolled shapes
- 1.3922 forged rings
- 1.3922 seamless rolled rings
- 1.3922 forged flanges
- 1.3922 forged discs and disks
- 1.3922 forged tube sheets
Bars and shafts
- 1.3922 forged round bars
- 1.3922 forged shafts and spindles
- 1.3922 forged eccentric shafts and crankshafts
- 1.3922 forged blocks and blanks
- 1.3922 forged gear blanks
Hollow and near-net parts
- 1.3922 forged sleeves and bushings
- 1.3922 forged tubes and pipes
- 1.3922 forged nozzles and manifolds
- 1.3922 forged valve bodies and valve stems
- 1.3922 forged valve seat rings
Typical size range: outside diameter 100 mm to 2500 mm for rings, diameter 30 mm to 800 mm for bars, single-piece weight up to 5000 kg. Send your drawing to confirm feasibility for sizes outside this range.
How we forge 1.3922
Ni48 forges well but the temperature window is narrow. Overheating coarsens the grain and finishing too cold causes tearing. The route below is the one we run for controlled-expansion alloys.
- Melting and ingot supply EAF and VOD refining followed by ESR remelting, for low sulfur and phosphorus and a homogeneous ingot without segregation.
- Heating Ingot soaked to 1150-1180 °C, held for section thickness, in a controlled-atmosphere furnace.
- Open-die forging or ring rolling Upset and drawn on hydraulic presses, or rolled on a radial-axial ring mill. Finishing temperature kept above 900 °C to avoid cracking.
- Annealing 850-1000 °C (1560-1830 °F) in a protective atmosphere, then cooled per the expansion requirement. Cold work is removed so the CTE returns to specification.
- Rough machining Turned or milled to the machining allowance on your drawing, so the part arrives ready for finishing.
- Testing and release Chemistry, mechanical testing, ultrasonic inspection and dimensional check before the certificate is issued.
Testing and certification
Ultrasonic testing
1.3922 forgings are ultrasonically tested to the standard named on your order. We routinely work to:
- EN 10228-3
- SEP 1921
- ASTM A388 / ASTM A388M
Certificates
Every lot ships with documentation matched to your quality plan:
- EN 10204 3.1 mill certificate
- EN 10204 3.2 third-party witnessed (SGS, BV, TUV, Lloyd's)
- Chemical analysis and mechanical test report
- Heat treatment chart and UT report
- Dimensional inspection report
Applications of 1.3922 forgings
Glass-to-metal sealing
The main use of the alloy. Forged rings, flanges and sleeves for hermetic seals in soft lead and soda-lime glass: electric lamp bulbs, vacuum devices, radio valves, microelectronic packages and feedthroughs.
Thermostats and controls
Thermostat rods, bimetal strip stock and positioning devices for industrial controls working continuously up to 450 °C (840 °F).
Electronics and instruments
Semiconductor lead frames, echo boxes and filters for mobile telephony, cavity resonators, magnetic shielding, small transformer cores, metrology fixtures and dimensionally stable optical mounts.
Aerospace composite tooling
Forged blocks and rings machined into moulds and layup tools where the tool must hold dimension through the autoclave cycle.
Cryogenic and LNG
Forged flanges, tube sheets and transfer-line components for LNG tankers and cryogenic handling, where thermal movement has to be predictable.
Valves and flow control
Forged valve bodies, stems, seat rings and blocks for ball, gate, globe, check, plug and strainer assemblies in specialist service.
Frequently asked questions about 1.3922
What is 1.3922 material?
1.3922 is the German Werkstoff number for Ni48, a nickel-iron controlled-expansion alloy with nominally 48 % nickel and the balance iron. It is standardised in DIN 17745 and cross-references to UNS K94800 and ASTM F30. Its thermal expansion matches soft lead and soda-lime glass, so it is used for glass-to-metal seals and for industrial thermostats.
What is 1.3922 equivalent to?
1.3922 is equivalent to UNS K94800, ASTM F30 and AFNOR NF A54-301. It is sold commercially as NILO 48, Pernifer 48, Glass Seal 48, Invar 48, SUPRA 50 and simply Alloy 48. The related German numbers 1.3926 and 1.3927 cover the same 48 % nickel alloy in different purity and form classes.
What is the chemical composition of 1.3922?
Nominally 48 % nickel with iron as the balance, plus maxima of 0.80 % Mn, 0.30 % Si, 0.10 % Cr, 0.05 % C, 0.025 % P and 0.025 % S. Nickel is held to a close range because it sets the expansion behaviour.
What is the difference between 1.3922 and Invar 36?
Both are nickel-iron alloys but they are specified for different reasons. Invar 36 (W.-Nr. 1.3912, 36 % Ni) has a near-zero expansion coefficient of about 1.5 x 10⁻⁶/K and is chosen when a part must not move at all. 1.3922 has a much higher coefficient of about 8.5 x 10⁻⁶/K, set to match soda-lime glass rather than to minimise movement. Use Invar 36 when a part has to hold dimension. Use 1.3922 when it has to seal to glass.
What is the maximum service temperature of 1.3922?
1.3922 is used in industrial thermostats continuously up to 450 °C (840 °F). Its inflection point is near 460 °C and its Curie temperature around 471 °C. Above that range the expansion behaviour changes and the alloy no longer works as a controlled-expansion material.
Can 1.3922 be open-die forged?
Yes. 1.3922 forges in the range 1150 °C down to a finishing temperature around 900 °C. It is produced as open-die forged rings, seamless rolled rings, flanges, bars, discs, shafts, sleeves, bushings, tubes and tube sheets. The alloy work-hardens, so forgings are annealed after forming to restore the expansion coefficient.
What heat treatment does 1.3922 need?
Annealing between 850 °C and 1000 °C (1560-1830 °F) in a protective atmosphere. Nilo type alloys are supplied and used annealed, because residual cold work distorts the coefficient of thermal expansion and makes a glass seal unreliable.
What sizes of 1.3922 forgings can you supply?
Rings from 100 mm to 2500 mm outside diameter, round bars from 30 mm to 800 mm diameter, and single-piece weights up to 5000 kg. All parts are made to drawing. Send dimensions or a DWG, STEP or PDF file and we will confirm feasibility.
What certificates do you supply with 1.3922 forgings?
EN 10204 3.1 mill certificates as standard, and EN 10204 3.2 third-party certificates on request through SGS, BV, TUV or Lloyd's. Ultrasonic testing is carried out to EN 10228-3, SEP 1921 or ASTM A388 as specified on the order.
Who supplies 1.3922 forgings?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, producing 1.3922 forgings to customer drawing and exporting worldwide. Enquiries: sales@steelforgepieces.com or +86 189 2135 9659.
How do I get a price for 1.3922 forgings?
Send the drawing or the finished dimensions, the quantity, the standard the part must meet and the certificate level you need. Price depends on weight, size, machining allowance and testing scope, so there is no list price for this grade.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory based in Jiangyin, Jiangsu Province, China, on the lower Yangtze near the ports of Shanghai and Zhangjiagang. We forge carbon steel, alloy steel, tool steel, stainless steel and nickel alloys into rings, flanges, bars, shafts, discs, sleeves and tube sheets, all to customer drawing. Controlled-expansion grades such as 1.3922, Invar 36 and Alloy 42 are a regular part of our work.
All work is made to order. We do not hold catalogue stock, and rough machining is done in-house so parts arrive ready for finishing. We ship against EN 10204 3.1 or 3.2 documentation to customers in Europe, North America, the Middle East, India and South-East Asia.
Address: No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City,
Jiangsu Province, China
Telephone: +86 189 2135 9659
Email: sales@steelforgepieces.com
Website: www.steelforgepieces.com
Document reference
Datasheet: 1.3922 / Ni48 open-die forgings. Issued by Jiangyin Jiangnan Metal Co., Ltd. Revision 2026-08. Source: https://www.steelforgepieces.com/Nickel-Alloy/1.3922.html Values in this datasheet are typical figures for material selection. Values for a delivered lot are those stated on the EN 10204 certificate.