Invar 36 Tubes
Invar 36 Tubes
Invar Tube offers extremely low thermal expansion, excellent dimensional stability, and good mechanical strength in a hollow cylindrical format suited for structural, optical, and cryogenic applications. The tubular geometry makes this iron-nickel alloy valuable where lightweight thermal stability and internal passageways are required. Industries including aerospace, precision engineering, and optics employ Invar tubes in structural supports, cryogenic vessels, and optical alignment systems. Specific applications include space-based instrument housings, structural members in cryogenic refrigeration, and conduits in high-precision optical devices. Research employs Invar tubes in thermal distortion studies, hybrid materials testing, and advanced cryogenic component design. The tube form ensures machinability, reduced weight compared to rods, and ease of integration into assemblies requiring low thermal distortion, reinforcing Invar’s role as a critical engineering material in aerospace, optics, and precision scientific instrumentation.

Common Trade Names: Invar 36®, Nilo 6®, Pernifer 6®.
Invar 36 Tube is available the following size ranges.
Outside Diameter - 0.25mm (0.010") up to 16.00mm (0.625")
Wall - 0.05mm (0.002") up to 1.00mm (0.040")
Straight Lengths - 1.00mm (0.040") up to 5000.00mm (197")
Coils Lengths - 5 Metres to 15 Metres
Standard Tolerance- OD &ID +/-0.03mm (0.0012")
Wall +/- 10%
Tight Tolerance - OD&ID +/- 0.015mm (0.0006")
Wall +/-3%
Some Invar 36 thin wall tubes up to 25.40 mm (1.000") can be supplied.
|
Invar 36 steel tubing other Brand Name |
Nickel Alloy 36 Tubing, Invar 36® Tubing and Nilo® 36 Tubing |
|
Invar 36 Tube Standards |
ASTM F1684, ASTM F30 |
|
Invar 36 Seamless Tube Size |
3.35 mm OD To 101.6 mm OD |
|
Invar 36 Welded Tube Size |
6.35 mm OD To 152 mm OD |
|
Swg & Bwg |
10 Swg., 12 Swg., 14 Swg., 16 Swg., 18 Swg., 20 Swg. |
|
Invar 36 tubing wall thickness |
0.020" –0.220", (special wall thicknesses available) |
|
Alloy 36 tube Length |
Single Random, Double Random, Standard & Cut length |
|
Specialize in |
Invar 36 Capillary Tube & Other Odd Size |
|
Invar Alloy 36 Tube Finish |
Polished, AP (Annealed & Pickled), BA (Bright & Annealed), MF |
|
Invar 36 tube Form |
Round, Coil, Square, Rectangular, Boiler, Hydraulic, Straight or ‘U’ bent Tubes, Hollow, LSAW Tubes Etc. |
|
Invar 36 Tube Type |
Seamless, ERW, EFW, Welded, Fabricated |
|
End |
Plain End, Beveled End, Treaded |
|
Marking |
All Invar Alloy 36 tubes are marked as follows: Standard, Grade, OD, Thickness, Length, Heat No. (Or according to the customer’s request.) |
|
Application |
Oil Tube, Gas Tube, Fluid Tube, Boiler and Heatexchanger |
|
Value Added Service |
Draw & Expansion as per required Size & Length, Polish (Electro & Commercial) Annealed & Pickled Bending, Machining Etc. |
|
Test Certificate |
Manufacturer Test Certificate |
|
We can also cut, thread, and groove Invar 36 Tubes to meet your specifications |
|
|
Types |
Out diameter |
Sizes |
Length |
|
Invar 36 Seamless Tube (Custom Sizes) |
OD6.35 mm To OD101.6 mm |
As per requirement |
Cut to length |
|
NB Sizes (in stock) |
.0035” ~ 8” |
1/8", 1/4", 3/8", 1/2", 5/8", 3/4", 1", 1.25", 1.5", 2", 2.5", 3", 4", 5", 6" |
Cut to length |
|
Invar 36 Welded Tube (ERW Tube) (in Stock + Custom Sizes) |
OD 6.35 mm To OD152 mm |
As per requirement |
Cut to length |
Invar 36 Seamles Tubes Surface Finish
|
Surface Finish |
Internal Surface(ID) |
Exterbal Surface(OD) |
|||
|
Roughness Average(RA) |
Roughness Average(RA) |
||||
|
μ inch |
μm |
μ inch |
μm |
||
|
EP |
Electro Polish |
15,10,7,5 |
0.38,0.25,0.20;0.13 |
32 |
0.8 |
|
MP |
Mechanical Polish |
40,32,25,20 |
1.0,0.8,0.6,0.5 |
32 |
0.8 |
|
AP |
Annealed & Pickled |
Not defined |
Not defined |
40 or Not defined |
1.0 or Not defined |
|
BA |
Beight Annealed |
40,32,25,20 |
1.0,0.8,0.6,0.5 |
32 |
0.8 |






