254 SMO stainless steel tube

254 SMO stainless steel tube

254 SMO stainless steel is a high-alloy austenitic grade with exceptional corrosion resistance, particularly in chloride-rich environments.

It has the following properties:

  • High strength
  • Moderate corrosion resistance
  • Good hardness and wear resistance
  • Highest hardness among stainless steel materials
  • Excellent abrasion resistance

Known for its high strength and toughness, 254 SMO is ideal for applications in seawater handling, chemical processing, and the oil and gas industries. Its resistance to pitting, crevice corrosion, and stress corrosion cracking makes it superior to standard stainless steels like 316. This material is often used in tubing for heat exchangers, desalination plants, and other demanding environments where durability and reliability are essential.

254 SMO is a high-performance austenitic stainless steel that contains high levels of chromium, molybdenum, and nitrogen. It is also known as UNS S31254 or 6 Moly due to its composition. 254 SMO stainless steel tubes are tubes made from this material and are suitable for use in corrosive environments.

This material has excellent resistance to pitting, crevice corrosion, and stress corrosion cracking, making it ideal for use in seawater handling equipment, chemical process vessels, and oil and gas production equipment.

Some of the key features of 254 SMO stainless steel tubes include:

  1. Excellent corrosion resistance: 254 SMO has superior resistance to corrosion in a wide range of aggressive environments, including seawater, acidic chloride-containing media, and other harsh chemical environments.
  2. High strength: 254 SMO stainless steel tubes have high strength and are capable of withstanding high pressure and temperature conditions.
  3. Good weldability: 254 SMO can be welded using conventional welding techniques such as TIG, MIG, and SMAW.
  4. Low thermal expansion: 254 SMO has a low coefficient of thermal expansion, which means that it is less likely to distort or deform under high-temperature conditions.

254 SMO stainless steel tubes are widely used in offshore and onshore applications involving harsh environments, as well as in the chemical and petrochemical industries, desalination plants, and pulp and paper manufacturing.

Manufacturing process

Since the 254S MO stainless steel tube is a high-alloy material, it is quite complicated in the manufacturing process. Generally, people can only rely on traditional techniques to manufacture such special stainless steel tubes, such asseamless, pouring, forging, calendering and the like.

Heat treatment

If additional heat treatment is needed due to further processing the following is recommended.
Solution annealing 1150–1200°C (2100–2190°F), quenching in water. Thin-walled tubes min. 1130°C (2060°F), quenching in air/water.

National standards

UNS S31254, DIN/EN 1.4547, ASTM A280, ASME SA-240

Matching welding consumables

ERNiCrMo-3 welding wire, ENiCrMo-3 welding rod

Chemical composition (nominal) %

Standards Grade C Si Mn P
S
Cr Ni Mo N Cu
Outokumpu 254 SMO ≤0.020 ≤0.80 ≤1.00 ≤0.030 ≤0.010 19.5-20.5 17.5-18.5 6.0-6.5 0.18-0.22 0.5-1.0
ASTM A182 F44 S31254 ≤0.020 ≤0.80 ≤1.00 ≤0.030 ≤0.010 19.5-20.5 17.5-18.5 6.0-6.5 0.18-0.22 0.5-1.0
DIN EN 10088-3-2005 X1CrNiMoN20-18-71.4547 ≤0.020 ≤0.70 ≤1.00 ≤0.030 ≤0.010 19.5-20.5 17.5-18.5 6.0-7.0 0.18-0.25 0.5-1.0

Mechanical properties

Standards Grade Tensile strength Yield strength Elongation Hardness
Outokumpu 254 SMO ≥650 MPa ≥300 MPa ≥ 35% ≤96 HRB

Features of 254SMO stainless steel tube

  1. 254SMO stainless steel pipes also have high crevice corrosion resistance in seawater, and only a few types of stainless steel pipes have this property.
  2. The corrosion resistance of 254SMO stainless steel tubes in acidic solutions and oxidizing halide solutions such as paper bleaching can be compared to nickel-based alloys and titanium alloys with the strongest corrosion resistance.
  3. Since the 254SMO stainless steel tube has a high nitrogen content, its mechanical strength is higher than other types of austenitic stainless steel tubes. In addition, the 254SMO stainless steel tube also has high ductility and impact strength as well as good weldability.
  4. The high molybdenum content of the 254SMO stainless steel tube allows it to have a higher oxidation rate during annealing, resulting in a rougher surface than the normal stainless steel tube after pickling. However, this has no adverse effect on the corrosion resistance of the steel.

Application areas of 254SMO stainless steel pipe

  1. Ocean: marine structures in the sea environment, seawater desalination, marine aquaculture, seawater heat exchange, etc.
  2. Environmental protection field: flue gas desulfurization device for thermal power generation, wastewater treatment, etc.
  3. Energy field: atomic power generation, comprehensive utilization of coal, and ocean wave power generation.
  4. Petrochemical industry: refining, chemical and chemical equipment.
  5. Food field: salt making, soy sauce brewing, etc.
  6. High concentration chloride ion environment: paper industry, various bleaching devices
254Smo stainless coil

254Smo stainless coil

254Smo stainless coil

254 SMO is an austenitic steel designed for maximum resistance to pitting and crevice corrosion. With high levels of chromium, molybdenum and nitrogen, 254 SMO is especially suited for high chloride environments such as brackish water, seawater, pulp mill bleach plants and other high-chloride process streams. In new construction, 254 SMO has been found in many cases to be technically adequate and much less costly substitute for nickel-based alloys and titanium. 254 SMO is readily fabricated and welded.

254Smo 0.6*1000mm In stock and customizable for cutting.

254Smo 0.8*1219mm In stock and customizable for cutting.

254Smo 1.0*1219mm Future goods, accepting orders.

254Smo 1.2*1219mm In stock and customizable for cutting.

254Smo 1.5*1219mm In stock and customizable for cutting.

254Smo 2.0*1219mm In stock and customizable for cutting.

254Smo 4.0*1219mm In stock and customizable for cutting.

Comparison table of stainless steel brands of various countries

In order to solve the cumbersome and difficult to remember stainless steel grades, improve the practicability of the brand representation, and the contrast with the international standard grades, China has formulated the "Universal Code System for Steel and Alloy Grades", such as 06Cr19Ni10, corresponding to 304. Different grades of stainless steel have different ingredients, but they all have a national standard. The standards of each country are also different.

The specific standards of each country are as follows:

No China,GB Japan American Korea EUR Indai Australia Tai Wan
Old New(07.10) JIS ASTM UNS KS BS EN IS IS CNS
Austenitic stainless steel
1 1Cr17Mn6Ni5N 12Cr17Mn6Ni5N SUS201 201 S20100 STS201 1.4372 10Cr17Mn6Ni4N20 201-2 201
2 1Cr18Mn8Ni5N 12Cr18Mn9Ni5N SUS202 202 S20200 STS202 1.4373   - 202
3 1Cr17Ni7 12Cr17Ni7 SUS301 301 S30100 STS301 1.4319 10Cr17Ni7 301 301
4 0Cr18Ni9 06Cr19Ni10 SUS304 304 S30400 STS304 1.4301 07Cr18Ni9 304 304
5 00Cr19Ni10 022Cr19Ni10 SUS304L 304L S30403 STS304L 1.4306 02Cr18Ni11 304L 304L
6 0Cr19Ni9N 06Cr19Ni10N SUS304N1 304N S30451 STS304N1 1.4315 - 304N1 304N1
7 0Cr19Ni10NbN 06Cr19Ni9NbN SUS304N2 XM21 S30452 STS304N2 - - 304N2 304N2
8 00Cr18Ni10N 022Cr19Ni10N SUS304LN 304LN S30453 STS304LN - - 304LN 304LN
9 1Cr18Ni12 10Cr18Ni12 SUS305 305 S30500 STS305 1.4303 - 305 305
10 0Cr23Ni13 06Cr23Ni13 SUS309S 309S S30908 STS309S 1.4833 - 309S 309S
11 0Cr25Ni20 06Cr25Ni20 SUS310S 310S S31008 STS310S 1.4845 - 310S 310S
12 0Cr17Ni12Mo2 06Cr17Ni12Mo2 SUS316 316 S31600 STS316 1.4401 04Cr17Ni12Mo2 316 316
13 0Cr18Ni12Mo3Ti 06Cr17Ni12Mo2Ti SUS316Ti  316Ti S31635 - 1.4571 04Cr17Ni12MoTi20 316Ti  316Ti
14 00Cr17Ni14Mo2 022Cr17Ni12Mo2 SUS316L 316L S31603 STS316L 1.4404 -02Cr17Ni12Mo2 316L 316L
15 0Cr17Ni12Mo2N 06Cr17Ni12Mo2N SUS316N 316N S31651 STS316N - - 316N 316N
16 00Cr17Ni13Mo2N 022Cr17Ni13Mo2N SUS316LN 316LN S31653 STS316LN 1.4429 - 316LN 316LN
17 0Cr18Ni12Mo2Cu2 06Cr18Ni12Mo2Cu2 SUS316J1 - - STS316J1 - - 316J1 316J1
18 00Cr18Ni14Mo2Cu2 022Cr18Ni14Mo2Cu2 SUS316J1L - - STS316J1L - - - 316J1L
19 0Cr19Ni13Mo3 06Cr19Ni13Mo3 SUS317 317 S31700 STS317 - - 317 317
20 00Cr19Ni13Mo3 022Cr19Ni13Mo3 SUS317L 317L S31703 STS317L 1.4438 - 317L 317L
21 0Cr18Ni10Ti 06Cr18Ni11Ti SUS321 321 S32100 STS321 1.4541 04Cr18Ni10Ti20 321 321
22 0Cr18Ni11Nb 06Cr18Ni11Nb SUS347 347 S34700 STS347 1.455 04Cr18Ni10Nb40 347 347
Austenitic ferritic stainless steel (duplex stainless steel)
23 0Cr26Ni5Mo2 - SUS329J1 329 S32900 STS329J1 1.4477 - 329J1 329J1
24 00Cr18Ni5Mo3Si2 022Cr19Ni5Mo3Si2N SUS329J3L - S31803 STS329J3L 1.4462 - 329J3L 329J3L
0Cr18Ni10Ti Iron type stainless steel
25 0Crl3Al 06Crl3Al SUS405 405 S40500 STS405 1.4002 04Cr13 405 405
26 - 022Cr11Ti SUH409 409 S40900 STS409 1.4512 - 409L 409L
27 00Cr12 022Cr12 SUS410L - - STS410L - - 410L 410L
28 1Cr17 10Cr17 SUS430 430 S43000 STS430 1.4016 05Cr17 430 430
29 1Cr17Mo 10Cr17Mo SUS434 434 S43400 STS434 1.4113 - 434 434
30 - 022Cr18NbTi - - S43940 - 1.4509 - 439 439
31 00Cr18Mo2 019Cr19Mo2NbTi SUS444 444 S44400 STS444 1.4521 - 444 444
Martensitic stainless steel
32 1Cr12 12Cr12 SUS403 403 S40300 STS403 - - 403 403
33 1Cr13 12Cr13 SUS410 410 S41000 STS410 1.4006 12Cr13 410 410
34 2Cr13 20Cr13 SUS420J1 420 S42000 STS420J1 1.4021 20Cr13 420 420J1
35 3Cr13 30Cr13 SUS420J2 - - STS420J2 1.4028 30 Cr13 420J2 420J2
36 7Cr17 68Cr17 SUS440A 440A S44002 STS440A - - 440A 440A

Stainless Steel Tube & Pipe Tolerance

In the production process, because the actual size is difficult to meet the nominal pipe size requirement, that is, it is often larger or smaller than the nominal size, so the standard stipulates that there is a difference between the actual size and the nominal size of the stainless steel pipe.

A positive difference is called a positive deviation, and a negative difference is called a negative deviation.

Outside diameter (OD), wall thickness and length are three basic parameters in the process of manufacture and distribution for stainless steel tube & pipe, and these parameters have been standardized.

Outer diameter and wall thickness are particularly important, they are not only the basic support for meeting the design requirements of various types of applications such as strength, stiffness and fluid delivery, but also have a decisive influence on the subsequent processing, therefore, standards for stainless steel tube & pipe diameter and wall thickness of the manufacturing accuracy (tolerance) should been standardized.

What is Nominal Pipe Size and Actual Pipe Size

A. Nominal Pipe size: It is the nominal size specified in the standard such ASME B36.10m, ASME B36.19m, the ideal size that users and manufacturers hope to obtain, and the order size specified in the contract.

B. Actual Pipe size: It is the actual size obtained during the production process, which is often larger or smaller than the nominal size. This phenomenon of being larger or smaller than the nominal size is called deviation.

European Standard

European stainless steel tube & pipe standards specify 4 classes outer diameter and wall thickness in percentage or absolute value on the basis of nominal dimension.

Generally, larger diameter or heavy wall thickness stainless steel pipe use percentage, small diameter or thin wall thickness stainless steel tube use absolute value.

European Standard

European stainless steel tube & pipe standards specify 4 classes outer diameter and wall thickness in percentage or absolute value on the basis of nominal dimension.

Generally, larger diameter or heavy wall thickness stainless steel pipe use percentage, small diameter or thin wall thickness stainless steel tube use absolute value.

Standard Manufacturing Process & Type Outer Diameter Tolerance Wall Thickness Tolerance Others
OD (Mm) Class
EN10216-5 Hot Finished Seamless Tube 219.1-610 D1 +22.5%T,-15%T T/D≤0.05
T1 T/D≤0.09
T2 T/D>0.09
30-219.1 D2 T1
T2
Cold Finished Seamless Tubes ≤219.1 D3 T3
D4 T4 Agreement
EN10297-2 Hot Finished Seamless Tube D1 T1
D2 T2 Agreement
Cold Finished Seamless Tubes D3 T3
D4 T4 Agreement
EN10217-7 Welded Tubes >168.3 D2 T3
≤168.3 D3 T3
D4 T3 Agreement
EN10296-2 Welded Tubes >168.3 D2 T3
≤168.3 D3 T3
≤114.3 D4 T3 Agreement
EN10312 Welded Tubes Series 1 D4 T3 T=0.6-2 Mm
Series 2 D3 – D4 T3 – T4 T=1-3 Mm

From D1 to D4 class for outer diameter, and T1 to T4 for wall thickness tolerance comply to DIN EN ISO 1127 standard, stainless steel tubes – Dimensions, tolerances and conventional masses per unit length.

Outside Diameter Wall Thickness
Class Tolerance Class Tolerance
D1 ±1.5%, Or ±0.75 Mm Min. T1 ±15%, Or ±0.6 Mm Min.
D2 ±1.0%, Or ±0.5 Mm Min. T2 ±12.5%, Or ±0.4 Mm Min.
D3 ±0.75%, Or. ±0.3 Mm Min. T3 ±10%, Or ±0.2 Mm Min.
D4 ±0.50%, Or ±0.1 Mm Min. T4 ±7.5%, Or ±0.15 Mm Min.
T5 +/- 5.0 %, Or +/- 0.10 Mm Min.

The tolerances on outside diameter and thickness from above table, greater value shall be selected.

EN 10312 has specific values in table series 1 and series 2.

America Standard

America standard has two standard rules to specify outside diameter and thickness, ASTM A999 / A999M and A1016 / A1016M.

ASTM A999 ASTM A1016
  • ASTM A312 / A12M
  • A358 / A358M
  • A376 / A376M
  • A409 / A409M
  • A778
  • A790 / A790M
  • A813 / A813M
  • A814 / A814M
  • A928 / A928M
  • A213 / A213M
  • A249 / A249M
  • A268 / A268M
  • A269
  • A270
  • A688 / A688M
  • A789 / A789M
  • A803 / A803M

But A511 for seamless stainless steel mechanical tubing and A554 welded stainless steel mechanical tubing not conform to above standards, they have separate outside diameter and thickness tolerances.

Standard Manufacturing & delivery condition Outside Diameter
OD / mm
OD tolerance mm Thickness
T / mm
T tolerance mm
Minimum Average
ASTM A1016
A1016M
Hot drawn seamless tubes <=100 +0.4, -0.8 <=2.4 +0.4t, 0
100 – 200 +0.4, -1.2 2.4 – 3.8 +0.35t, 0
200 – 225 +0.4, -1.6 3.8 – 4.6 +0.33t, 0
>=4.6 +0.28t, 0
Cold drawn seamless tubes <25 +0.1, -0.11 +0.20t, 0 +/-0.10t
25 – 40
40 – 50 +/-0.2 +0.22t, 0 +/-0.10t
50 – 65 +/-0.25
65 – 75 +/-0.3
75 – 100 +/-0.38
100 – 200 +/-0.38, -0.04
200 – 250 +/-0.38, -1.14
Welded tubes 40 – 50 +/-0.2 +0.18t, 0 +/-0.10t
50 – 65 +/-0.25
65 – 75 +/-0.3
75 – 100 +/-0.38
100 – 200 +/-0.38, -0.04
200 – 250 +/-0.38, -1.14
ASTM A999 / M Seamless tubes and welded tubes <48.3 +0.4, -0.8 -0.125t
ASTM A312 / M Seamless tubes and welded tubes 48.3-114.3 +/-0.8 OD=10.3-73 +0.20 t, -125t
168.3-219.1 +1.6, -0.8 t/OD<=5% OD=88.9-457.2 +0.225 t, -125t
219.1-457.2 +2.4, -0.8 t/OD>5% OD=88.9-457.2 +0.15 t, -125t
Welded tubes 508-660 +3.2, -0.8 OD>=508 +0.175 t,-0.125 t
711-864 +4.0, -0.8 t/OD<=5%, OD>=508 +0.225 t,-0.125 t
Seamless tubes 914-1209 +4.8, -0.8 t/OD>5%, OD>=508 +0.15 t, -125t
ASTM A409 / M Welded tubes +/-0.2% T<4.8
+/-0.4% t>=4.8
ASTM A358 / M Welded tubes   +/-0.50%
ASTM A511 Seamless tubing <=12.7 +/-0.1 +/-0.15t
12.7-38.1 +/-0.2 +/-0.10t
38.1-88.9 +/-0.3
88.9-139.7 +/-0.4
139.7-203.1 +/-0.8
203.1-220 +/-1.1
220-325 +/-1.6

American standard outside diameter tolerance mainly used to represent the absolute value, over and below tolerances are often asymmetric, SS tube and pipe in American standard average tolerance can reach even higher than D4 class in EN ISO 1127 standard.

Wall thickness tolerance should be +/-10%t or better, and average thickness tolerance should be ( +/-20 – 22%t, 0 ), pipeline pipe has a larger tolerance, hot finished seamless pipe largest.

China Standards

China has more quantity standards compared to European standards, but less than american standards, SS tube and pipe standards are similar with EU standards in system, and absorb favorable experience in USA specifications.

Specification Manufacturing O.D(Mm) O.D Tolerance W.T(Mm) W.T Tolerance
GB13296 Cold Rolled Seamless Pipe 6-30 ±0.15/-0.2 1-3 +20% -0%
>30-50 ±0.3 >3 +22% -0%
>50 ±0.75% Also Average Wall
GB/T14976 Cold Rolled Seamless Tube 6-10 ±0.15 1-3 +12.5% -12.5%
10-30 ±0.2 >3 +12.5% -10%
30-50 ±0.3 Average Wall, +22%
>50 ±0.8%

Standard Comparison

Stainless steel tube & pipe wall thickness tolerance are the same as the general accuracy of American ASTM / ASME and EU standards, but slightly lower than the high requirements of the EU standards.

Stainless steel tube & pipe outer diameter tolerances are mostly lower than American standards, and approaching the EU standards. it is more reasonable that the American standard specify the OD tolerance is tight, compared to thickness tolerance.

China GB standards and EU standard have no weight tolerance specified, seamless tube & pipe in GB standard delivery goods as actual weight or theoretical weight, welded tube & pipe as theoretical weight or actual weight.

Out Of Roundness

Out of roundness, sometimes referred to as ovality is tube or pipe on the same cross-section of the outer diameter, roundness or ovality is difference between the maximum and minimum dimensions of outside diameter, is carefully measured the high and low points at any one section of the tube or pipe.

tube pipe ovality

Eccentricity

Concentricity or eccentricity refers to tube & pipe wall thickness variations, if need a high precision in tube tolerance, or fit into other tube or parts, which need a good concentricity.

Stainless steel tube pipe eccentricity

Concentricity be contained wall thickness tolerance specified in EU standard, and just specified in ASTM A1016/M OD≥50 mm and t≥5.6 mm thick wall stainless steel tube the same cross section thickness varieties.

For seamless tube,

WTmax – WTmin ≤ ±10% (WTmax + WTmin) / 2

For welded tube,

WTmax – WTmin ≤ 5% (WTmax + WTmin) / 2

Straightness

Standard pipes and tubes are supplied straightened to the eye: for special applications the permissible deviation from the straight line may be agreed between purchaser and tube manufacturer; the maximum permissible deviation from the straight line related to the length of measurement L is to be indicated, e.g. 1mm/1000mm.

Stainless steel tube pipe straightness

For example:

OD Mm ≤ OD Inches ≤ Wall Straightness Commercial FT Achievable Mm
15.9 0.625 All Sizes 1 In 600 1 In 2000
25.4 1.00 2% Of OD Or Heavier 1 In 600 1 In 1500
25.4 1.00 Less Than 2% Of OD 1 In 400 1 In 1000

Length of stainless steel pipe and tube

Delivery length is also called the length required by the user or the length of the order. The standard has the following regulations on delivery length:

A. Normal length / Random Length (also called non-fixed-length length): Any stainless steel tube whose length is within the length range specified by the standard and has no fixed length requirement is called normal length. For example, the structural stainless steel pipe standard stipulates: hot-rolled (extruded, expanded) steel pipe 3000mm - 12000mm; cold drawn (rolled) steel pipe 2000mm - 10500mm.

B. Fixed Length: The fixed-length should be within the usual length range, which is a certain fixed-length dimension required in the contract. However, it is impossible to cut out the absolute fixed-length length in actual operation, so the standard stipulates the allowable positive deviation value for the fixed-length length.

Tied universal expansion joint applications

Take the structural stainless steel pipe standard as:

The yield rate of production of fixed-length pipes is much lower than that of normal-length pipes, and it is reasonable for manufacturers to request price increases. The rate of price increase varies from company to company. Generally, the price increase is about 10% on the basis of the base price.

C. Length of double ruler: The length of the double ruler should be within the usual length. The contract should indicate the length of the single ruler and the multiples of the total length (for example, 3000mm×3, which is 3 multiples of 3000mm, and the total length is 9000mm). In actual operation, the allowable positive deviation of 20mm should be added to the total length, plus a margin for the incision of each single ruler length. Take the structural pipe as an example, the allowance for cutting is stipulated: 5-10mm for outer diameter ≤159mm; 10-15mm for outer diameter >159mm.

If there is no double-length deviation and cutting allowance in the standard, it should be negotiated by the supplier and the buyer and indicated in the contract. The double-length scale is the same as the fixed-length length, which will bring about a substantial reduction in the yield rate of the manufacturer. Therefore, it is reasonable for the manufacturer to raise the price, and the price increase is basically the same as the fixed-length length.

D. Range length: The range length of the stainless steel pipe is within the usual length range. When the user requires a fixed range length, it must be indicated in the contract.

For example: Usually the length is 3000-12000mm, and the range cut-to-length length is 6000-8000mm or 8000-10000mm.

It can be seen that the range length is looser than the fixed-length and double-length length, but it is much stricter than the usual length, which will also reduce the yield of production enterprises. Therefore, it is reasonable for the manufacturer to raise the price, and the price increase is generally about 4% above the base price.

Application

Stainless steel pipe (tube) has excellent characteristics of corrosion resistance and smooth finishing. Stainless steel pipe (tube) is commonly used in demanding equipment like automobiles, food processing, water treatment facilities, oil and gas processing, refinery and petrochemicals, breweries and energy industries.

The stainless steel tubing that is supplied by SunnySteel can used in a variety of industries, including:

Considering the importance of outside and inside surface of stainless steel tubes for fluid power industry, Our mills are providing tubes that are free from scale, rust, seams, laps.

application
  • Machinery Parts
  • Pharmaceutical
  • Biotechnology
  • Automotive
  • Oil and Gas
  • Marine
application
  • Food and Beverage Processing
  • Construction
  • Automotive industries
  • Food processing
  • Water treatment facilities
  • Breweries and energy industries
Stainless steel ERW tube

Stainless steel ERW tube

Stainless Steel Density

Stainless steel density refers to substance mass per unit volume, it is one of typical property of stainless steel, commonly, density of stainless steel range from 7600 kg/m3 to 8000 kg/m3.

Stainless steel is a wide used material, containing at least 10.5% of Chromium, and other elements added to form stainless steel structure, these elements have Carbon, Silicon, Manganese, Phosphorus, Sulfur, Nickel, Molybdenum, Titanium and Copper, it is noted as high strength and excellent corrosion resistance.

Densities change depending on these alloy elements changing, different alloy content have different density value, even it is the same grade, it is difficult to calculate accurate density values, theoretic density value is given below for reference.

The following is the comparison of several commonly used stainless steel density, data may not be completely accurate, only for reference.

Stainless Steel Density Table Chart

Grade Density ( G / Cm3 ) Density ( Kg / M3 )
201
202
301
302
303
304
304L
304LN
305
321
7.93 7930
309S
310S
316
316L
316Ti
316LN
317
317L
347
7.98 7980
904L 7.98 7980
2205
S31803
7.80 7800
S32750 7.85 7850
403
410
410S
416
431
7.75 7750
440A 7.74 7740
440C 7.62 7620
420 7.73 7730
439
430
430F
7.70 7700
434 7.74 7740
444 7.75 7750
405 7.72 7720

*These densities given at standard conditions for temperature and pressure condition.

304 And 316 Stainless Steel Densities

304 and 316 are the most used stainless steel grades, their densities are not the same, this decide by chemical composition and content, stainless steel 304 density is 7930 kg / m3, 316 density is 7980 kg / m3, so when calculating stainless steel weight, it is different between 304 and 316 stainless steel.

Stainless Steel Density Conversion, Kg/M3, G/Cm3 And Lbs/In3
Density of stainless steel calculated by dividing the mass by the volume, usually measured in g/cm3, kg/m3, and lbs/in3, each unit can be converted to other units.

Conversion: 1 kg/m3 = 0.001 g/cm3 = 1000 g/m3 = 0.000036127292 lbs/in3.

Density Relations With Temperature And Pressure

Densities of stainless steel vary by changing either the temperature or the pressure, in general, increasing the temperature decreases the density, increasing the pressure always increases the density.

Difference Between Seamless And Welded Tube & Pipe

Seamless and welded are mainly two types stainless steel tube & stainless steel pipe, there is a debate whether seamless is better than welded for a long time.

Although with improved metallurgy and welding processes in welded tubes, the arguments typically focus on structural integrity and corrosion resistance in weld area.

Obviously, seamless and welded tubes & pipes difference is manufacturing process.

Precision Seamless Pipe

There are some cases where paying extra for a different, higher-performing alloy is necessary.

Welded Tube Manufacturing Process

Depending on the outer dimension, wall thickness and final application, there are different ways of manufacturing welded tubes and pipes, and different manufacturing method.

Strip Welded Tubes & Pipes

Welded tube start from stainless steel strip and coil that is passed through grooved rollers till the shape is formed and the free edges are properly shaped for welding, cold forming is performed step by step from flat strip into a round profile, the edges are welded together as they approach the welding rolls.

Typical welding method for strip welded tubes is traditionally autogenous tungsten inert gas (TIG), TIG welding method have some advantages that can effectively protect weld seam.

After welding outside and inside grinding of the weld seam, solution annealing or stress relieving may be necessary by application requirements.

  • Coil
  • Inspection and analysis
  • Slitting
  • Auto-welding
  • Seam-grinding
  • Solution treatment
  • Cut to length
  • Straightening
  • Picking
  • End-facing
  • Eddy current test
  • Hydrostatic test
  • Final inspection
  • Marking
  • Packing
  • Shipping
Tig welding stainless steel tubing

Tig welding stainless steel tubing

Today, most of the modern welding lines are equipped with inline induction annealing, then straitening and calibration to control dimension of tube & pipe, cut to standard or special lengths, de-burred, NPD & DT testing and inspection should be carried out as standard or requirement.

Heavy Wall Tubes & Pipes

When large outside diameter or heavy wall or both welded tubes & pipes required, there is a different welding method and process, for large diameter and heavy wall pipes, EFW, ERW and other welding methods can be used.

Starting from stainless steel plate or sheet, the forming is done in a roller bending machine or in a hydraulic press, then some steps are same with strip welded tubes.

  • Plate
  • Inspection
  • Plasma-cutting
  • Edging
  • Bending
  • Seam cleaning
  • Forming
  • Auto- welding
  • Degreasing
  • Anneaspanng
  • Roundness caspanbrating
  • End-facing
  • Eddy current test
  • Hydrostatic test
  • Final inspection
  • Marking
  • Packing
  • Shipping

For testing and inspection, large diameter sizes, radiography test (RT) and hydrostatic test (HT) are often required.

For large diameter welded pipes, double welding method can be accepted.

Delivery

Steel pipe delivery status(condition)

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Condition on delivery of steel pipe

Term Symbol Explanation
Cold-finished/hard (cold-finished as-drawn) BK No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft (lightly cold-worked) BKW After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed GBK After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized NBK The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.

Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.

Packing

Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for sea-worthly delivery or as requested.

There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method to work prevent rusting and Sea transportation security.

Steel strips bunding for fixed pipes

Our packing can meet any needs of the customers.

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Placing steel pipes into containers

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Value-added services

BEVELING

Beveling Stainless Steel tubes contain one end angled, so that it mates with a complementary tube end. Tubes can be beveled for certain applications in order to make welding of stainless steel tubes easier, which saves weld prep time and money compared to hand cutting.

HEAT TREATING & ANNEALING

Eastern Steel can heat treat some 400 series stainless steel seamless tube. Heat treating realizes stress as a result of hardening, depending upon the chemistry of the metal being treated. Heat treating is also used for tempering, quenching, normalizing, and solution annealing.

HONING & TURNING

During the honing/turning process, an abrasive rotating tool removes metal from the interior surface of a cylinder, pipe, or tube. The main purpose of honing is to finish the surface to a particular diameter and/or desired cylindrical geometric design. Honing is typically a secondary machining operation that completes a produce/part, relieves stress created during production, or corrects features of the finished product. A typical production cycle is to drill, ream, heat treat, then hone.

POLISHING

POSITIVE MATERIAL IDENTIFICATION (PMI)

In some cases, it may be necessary to complete additional positive material identification testing. Eastern Steel can complete this testing in house or we can work with an independent laboratory to complete the testing. Please contact us for specific requirements.

UT TESTING

Ultrasonic Testing (UT) utilizes sound energy at high frequencies, in order to provide examinations and measurements of the stainless steel product. This aids in flaw detection/evaluation, dimensional measurements, etc.

Alloying Elements

Commonly used alloying elements and their effects are listed in the table given below.

Alloying Elements Effect on the Properties
Chromium Increases Resistance to corrosion   and oxidation. Increases hardenability and wear resistance. Increases high   temperature strength.
Nickel Increases hardenability. Improves   toughness. Increases impact strength at low temperatures.
Molybdenum Increases hardenability, high   temperature hardness, and wear resistance. Enhances the effects of other   alloying elements. Eliminate temper brittleness in steels. Increases high   temperature strength.
Manganese Increases hardenability. Combines   with sulfur to reduce its adverse effects.
Vanadium Increases hardenability, high   temperature hardness, and wear resistance. Improves fatigue resistance.
Titanium Strongest carbide former. Added to   stainless steel to prevent precipitation of chromium carbide.
Silicon Removes oxygen in steel making.   Improves toughness. Increases hardness ability
Boron Increases hardenability. Produces   fine grain size.
Aluminum Forms nitride in nitriding steels.   Produces fine grain size in casting. Removes oxygen in steel melting.
Cobalt Increases heat and wear   resistance.
Tungsten Increases hardness at elevated   temperatures. Refines grain size.

【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.