TOHSEI KOKAN CO., LTD.

Ultra-precision Tubes

What is “ultra-precision tubes”?

“Ultra-precision tubes” are tubes finished to meet customer specifications, such as high-precision dimensional tolerances and excellent surface roughness. We stretch the tubes using cold three-roll rolling or cold drawing processes. By performing bright annealing in a hydrogen atmosphere in an oxidation-free environment, the product does not develop discoloration and no oxide film forms on the metal surface, resulting in a mirror finish. We can also accommodate vacuum annealing (VA) and internal electrolytic polishing (EP) upon request. Please feel free to contact us.

Dimensional Manufacturing Range

Outer diameter: φ0.25 – φ30
Thickness: ≥ t 0.02
Length: L5mm – 14,000mm

Materials with Track Record

Stainless steel, Inconel, Hastelloy, other nickel alloys, aluminum, copper, nickel, titanium, niobium, tantalum

Key Strengths of Ultra-Precision Tubes

High-precision dimensional tolerances (track record: inner/outer diameter ±0.01)
Excellent surface roughness (track record: inner/outer surface ≦Ra0.4)
Mechanical properties exceeding JIS standard values (track record: elongation ≧50%; standard: ≧35%)
Manufacture of ultra-long tubes (track record: maximum length 14m)
Manufacture of ultra-fine tubes (track record: minimum outer diameter φ1.2)
Manufacture from short round bars High yield rate
Manufacture from short round bars
High yield rate
Appropriate heat treatment according to material
Flexible support for finishing methods

Dimensional Manufacturing Range

Outer diameter: φ0.25 – φ30　Thickness: ≥ t 0.02　Length: L5mm – 14,000mm

Materials with Track Record

Stainless steel
SUS304, SUS304L, SUS316, SUS316L, SUS321, SUS347, SUH660
Inconel
NCF600, NCF601, NCF625
Hastelloy
HC-276, HC-22
Other nickel alloys
Permalloy CP-2, Monel 400, NCH-1
Aluminum
5N-AL, A1080, A6063
Copper
C1020, C1011, C1220
Nickel
NW2201
Titanium
TTP270C, TTP340W, TTP340C
Niobium
Tantalum

How We Achieve This

High-precision dimensional tolerances (track record: inner/outer diameter ±0.01)
Because the inner and outer diameters can be adjusted in units of 0.01, high-precision inner/outer diameter tolerances can be accommodated.
Excellent surface roughness (track record: inner/outer surface ≦Ra0.4)
Since the cold 3-roll rolling method is a low-speed processing method, there is less frictional resistance with the tooling, making excellent surface roughness achievable.
Mechanical properties exceeding JIS standard values (track record: elongation ≧50%; standard: ≧35%)
Because the cold 3-roll rolling method elongates the tube at a high reduction ratio, it enables refinement of the crystal grain size, making it possible to improve mechanical properties beyond the standard values.
Manufacture of ultra-long tubes (track record: maximum length 14m)
The cold 3-roll rolling method enables elongation processing of ultra-long tubes exceeding 12m while maintaining stable dimensional accuracy.
Manufacture of ultra-fine tubes (track record: minimum outer diameter φ1.2)
The cold drawing method makes it possible to manufacture ultra-fine tubes down to an outer diameter of φ0.25 and a thickness of t0.02.
Manufacture from short round bars
Since the cold 3-roll rolling method does not require a leading-end point (tip forming), short round bars can be bored into short tubes and then processed into fine tubes.
High yield rate
Since the cold 3-roll rolling method does not require a leading-end point (tip forming), there is no wasted material from removal, allowing for a higher yield rate.
Appropriate heat treatment according to material
By performing bright annealing (BA) or vacuum annealing (VA), appropriate heat treatment can be carried out according to the material.
Flexible support for finishing methods
After heat treatment, finishing can be tailored to the customer’s requirements, with polishing (belt, buff, brush, or electropolishing (EP)) available for the inner and outer surfaces.