There are several types of bellows, such as welded bellows and molded bellows, depending on the manufacturing method.
Bellows are used for pressure sensing and sealing because they can flexibly expand, contract, and bend while maintaining a tight seal for gases and liquids. Metal bellows have superior strength, corrosion resistance, and heat resistance, and are widely used in vacuum equipment for semiconductor manufacturing equipment, as well as in the aerospace and medical fields.
Bellows for semiconductor manufacturing equipment and vacuum equipment, actuated valves for air conditioners, diaphragms for cooling equipment
Thickness : 0.010mm-2.0mm *Availability may vary by steel grade.
Width : 3.0mm-300mm *Contact Sales if your desired values is over 300mm.
Length : COIL or SHEET less than L2000mm
TOKKIN manufactures the following materials for bellows.
Please select your designated material that best suits your environment of use and purpose.
Please scroll horizontally to view.
| Grade | Strength * |
Heat Resistance | Corrosion Resistance | Cost | Features |
|---|---|---|---|---|---|
| SUS304 SUS304L |
B | A | B | S | Standard (18% chromium, 8% nickel) austenitic stainless steel and is the most commonly used grade of stainless steels. It has good workability, weldability, heat resistance, and corrosion resistance, used for general applications. |
| SUS316 SUS316L |
B | A | A | S | Austenitic chromium-nickel stainless steel containing molybdenum. This addition increases corrosion resistance, improves resistance to pitting chloride ion solutions and provides increased strength at elevated temperatures. Properties of this austenitic stainless steel grade are similar to those of type 304 except that type 316 is somewhat stronger at elevated temperature ranges. |
| TOKKIN 350 | S | B | A | A | A chromium-nickel-molybdenum precipitation hardening stainless steel used for applications requiring high fatigue strength and excellent weldability along with corrosion and oxidation resistance. |
| Alloy 625 | A | S | S | B | A non-magnetic nickel-chromium alloy with excellent heat resistance, corrosion resistance, and oxidation resistance. |
| HC-22 HC-276 |
A | S | S | B | A nickel-chromium-molybdenum alloy with excellent resistance to both oxidizing and non-oxidizing chemicals, and protection from pitting, crevice attack, and stress corrosion cracking. Used in applications where oxidation and reduction occur repeatedly. |
S ･･･ Excellent A ･･･ Good B ･･･Moderate
* Strength of bellows
Bellows materials and corresponding standard specifications are shown in the table below.
Please scroll horizontally to view.
| Grade | UNS | AISI | Standard | Others |
|---|---|---|---|---|
| SUS304 | S30400 | 304 | JIS G4305 | |
| SUS304L | S30403 | 304L | JIS G4305 | |
| SUS316 | S31600 | 316 | JIS G4305 | - |
| SUS316L | S31603 | 316L | JIS G4305 | |
| TOKKIN 350 | S35000 | 633 | AMS 5548 | ASTM A693(Type 633) |
| Alloy 625 | N06625 | --- | AMS 5599 AMS 5666 |
ASTM B443 |
| HC-276 | N10276 | --- | ASTM B574 ASTM B575 |
|
| HC-22 | N06022 | --- |
Please scroll horizontally to view.
| Grade | C | Si | Mn | P | S | Cr | Ni | Mo | N | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| SUS304 | 0.08 max | 1.00 max | 2.00 max | 0.045 max | 0.030 max | 18.00-20.00 | 8.00-10.50 | - | - | Bal. |
| SUS304L | 0.030 max | 1.00 max | 2.00 max | 0.045 max | 0.030 max | 18.00-20.00 | 9.00-13.00 | - | - | Bal. |
| SUS316 | 0.08 max | 1.00 max | 2.00 max | 0.045 max | 0.030 max | 16.00-18.00 | 10.00-14.00 | 2.00-3.00 | - | Bal. |
| SUS316L | 0.030 max | 1.00 max | 2.00 max | 0.045 max | 0.030 max | 16.00-18.00 | 12.00-15.00 | 2.00-3.00 | - | Bal. |
| TOKKIN 350 | 0.07-0.11 | 0.50 max | 0.50-1.25 | 0.040 max | 0.030 max | 16.00-17.00 | 4.00-5.00 | 2.50-3.25 | 0.07-0.13 | Bal. |
Please scroll horizontally to view.
| Grade | Mo | Cr | Fe | W | Co | C | Si | Mn | V | p | S | Ni | Nb | Ti | Al |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Alloy 625 | 8.0-10.0 | 20.0-23.0 | 5.0 max | - | 1.0 max | 0.10 max | 0.50 max | 0.50 max | - | 0.015 max | 0.015 max | Bal. | 3.15-4.15 | 0.40 max | 0.40 max |
| HC-276 | 15.0-17.0 | 14.5-16.5 | 4.0-7.0 | 3.0-4.5 | 2.5 max | 0.02 max | 0.08 max | 1.0 max | 0.35 max | 0.004 max | 0.03 | Bal. | - | - | - |
| HC-22 | 12.5-14.5 | 20.0-22.5 | 2.0-6.0 | 2.5-3.5 | 2.5 max | 0.015 max | 0.08 max | 0.5 max | 0.35 max | 0.025 max | 0.02 | Bal. | - | - | - |
Physical Properties are shown in the table below.
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| Grade | Density ［g/cm3 ］ |
Specific Heat ［J/(kg・K)］ |
Electrical Resistance ［μΩ・cm］ |
Young's Modulus ［GPa］ |
Thermal Expansion ［×10-6/K］ |
Thermal Conductivity ［W/(m・K)］ |
Magnetism |
|---|---|---|---|---|---|---|---|
| SUS304 | 7.9 | 502 | 72 | 193 | 17.3 | 16.3 | None or Weak (Depends on the finish) |
| SUS316 | 8.03 | 502 | 74 | 193 | 16 | 16.3 | None or Weak (Depends on the finish) |
| TOKKIN 350 | 7.92 | 461 | 79 | 200 | 15.2 | 15.4 | Strong |
| Alloy 625 | 8.44 | --- | 129 | 207.5 | 12.8(93℃) | 9.8(21℃) | None |
| HC-276 | 8.89 | 427 | 130 | 205 | 11.2 | 11.1 | None |
| HC-22 | 8.89 | 414 | 114 | 206 | 12.4 | 11.1 | None |
In general, for bellows applications, we supply 2B-finished products that have been lightly rolled (skin-pass) to compensate for strain in the annealed condition.
The mechanical properties of each material in 2B finish are shown in the table below, but since we can flexibly set specifications based on made-to-order production, please contact us before placing an order.
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| Material | Thickness ［mm］ |
Annealed finish（BA, 2B） | After SCT850 treatment | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Hardness ［HV］ |
Tensile Strength ［MPa］ |
Yield Strength ［MPa］ |
Elongation ［%］ |
Hardness ［HV］ |
Tensile Strength ［MPa］ |
Yield Strength ［MPa］ |
Elongation ［%］ |
||
| TOKKIN 350 | 0.030-0.051 | Negotiable* | 1393 max | 641 max | 9 min | Negotiable* | 1276 min | 1034 min | 4 min |
| 0.051-0.127 | Negotiable* | 1372 max | 627 max | 10 min | Negotiable* | 1276 min | 1034 min | 6 min | |
| 0.127-0.254 | Negotiable* | 1351 max | 614 max | 12 min | Negotiable* | 1276 min | 1034 min | 6 min | |
| 0.254-0.508 | Negotiable* | 1331 max | 600 max | 14 min | Negotiable* | 1276 min | 1034 min | 8 min | |
*Hardness is for reference only if tensile test values are satisfied. Please contact us if you require hardness standards.
Please scroll horizontally to view.
| Grade | Annealed finish（BA, 2B） | |||
|---|---|---|---|---|
| Hardness ［HV］ |
Tensile Strength ［MPa］ |
Yield Strength ［MPa］ |
Elongation ［%］ |
|
| SUS304L | 220 max | 480 min | 175 min | 40 min |
| SUS316L | 220 max | 480 min | 175 min | 40 min |
| Alloy 625 | 240 max | 827 min | 414 min | 30 min |
| HC-276 | 260 max | 690 min | 283 min | 40 min |
| HC-22 | 260 max | 690 min | 310 min | 45 min |
[Note] Warranty coverage may vary depending on board thickness and other factors.
Stainless Steels, Nickel Alloys, Cobalt Alloys, Carbon Steels etc.
We can manufacture foils in all the materials we manufacture.
Alloys based on Nickel (Ni), Chromium (Cr), Cobalt (Co), and Titanium (Ti) are superior to stainless steel in terms of heat resistance and corrosion resistance.
