What is the Chinese equivalent of NiCr 40/20 or Ni40Cr20?

GB Cr20Ni35. NiCr 40/20 has Ni ≥37.0%, Cr 18–22%, Si 1.8–3.0% and resistivity ≈1.05 μΩ·m; GB Cr20Ni35 has Ni 34.0–37.0%, Cr 18.0–21.0%, Si 1.00–3.00% and resistivity 1.04 μΩ·m. The two overlap across the composition range.

Is there a grade called Cr20Ni40 in the Chinese standard?

No. GB/T 1234 does not define Cr20Ni40. Some Chinese suppliers use it as a commercial name, but the standardised grade is Cr20Ni35.

Does NiCr 40/20 have an ASTM or DIN number?

No. It has no ASTM, UNS, Werkstoff or DIN designation — it is an industry trade grade.

Can NiCr 40/20 be used in a sulphur-bearing atmosphere?

No. All nickel-chromium grades are unsuitable in sulphur atmospheres. Use FeCrAl instead.

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Heating Tubes & Cartridge Heaters

Short answer: we make single-end cartridge, double-end, U-type, finned and flanged electric heating tubes, in stainless, Incoloy and titanium sheaths, with watt density matched to the medium.

Watt density is the number that decides tube life
A tube in water can run 5–8 W/cm²; the same tube in oil should not exceed 2–3 W/cm²; in still air, 1–2 W/cm². Exceed it and the sheath temperature climbs, scale forms faster, and the tube fails from the outside in. When a tube fails early, measure the sheath temperature before blaming the element.

1. Construction types

Type	Typical use	Common sheath OD	Note
Single-end (cartridge)	Dies, platens, small blocks	φ6 – 25 mm	Needs a close-tolerance bore for good heat transfer
Double-end	Tanks, ducts, ovens	φ8 – 20 mm	Both terminals at one end
U-type / W-type	Tanks, large baths	φ8 – 20 mm	More power in a shorter immersion length
Finned	Forced-air ducts	φ8 – 16 mm	Fins reduce surface load in air
Flanged / screw-plug	Pressurised tanks	to order	Sealing is part of the specification

2. Watt density by medium

Medium	Watt density (W/cm²)	Reason
Water	5 – 8	Excellent heat transfer
Oil	2 – 3	Local overheating causes coking on the sheath
Acid / alkaline solution	1.5 – 3	Corrosion accelerates with sheath temperature
Forced air	2 – 4	Depends on face velocity
Still air	1 – 2	Poorest transfer — take the low end

3. Sheath material

Sheath	Use	Avoid
304 / 321 stainless	Water, mild solutions, air	Chlorides
316L	Mildly corrosive solutions	Strong chlorides at temperature
Incoloy 800 / 840	Higher sheath temperature, air	—
Titanium	Chloride-bearing solutions	Dry air at high temperature

4. Please confirm these 4 points before ordering

Medium and its temperature — this decides both watt density and sheath material.
Power, voltage and connection — single-phase or three-phase, and star or delta.
Immersion length and thread/flange — so the heated length sits fully in the medium.
Whether the medium fouls or scales — if it does, ask for the lower watt density.

Need a quotation?

Send grade, form, size with tolerance and quantity — we reply within one working day (GMT+8).

WhatsApp +86 180 6103 5177 Enquiry form

About Taizhou Aolante Alloy

Taizhou Aolante Alloy Materials Co., Ltd. was founded in 2010 and is a source manufacturer of electric heating alloys, precision resistance alloys and furnace accessories. Production base in Taixing, Taizhou, Jiangsu, approximately 20,000 m², 48+ pieces of melting, forging, rolling, drawing, heat-treatment and testing equipment, 200+ staff, annual capacity about 7,500 tonnes.

Our range covers heating wire and strip, heating cable, wide thin strip, radiant tubes, heat-resistant steel, conveyor belts, superalloys, industrial furnaces, thermocouples, refractory insulation, heating tubes, CuNi/MnCu alloys, far-infrared quartz tubes.

Contact: Tel +86 180 6103 5177 / +86 523 8751 8610 | Email althjcl@126.com

Grade cross-references are commercial equivalents, not a guarantee of interchangeability. Final acceptance is subject to the composition sheet agreed at order.