|A249/ A249M||A269||A270||A778||A335/ A335M||A691|
|A790||A312||A409||A554||A358/ A358M||A928/ A928M|
CS pipe Grades
|(C) Carbon, max||0.030||0.030||0.08|
|(Mn) Manganese, max||2.00||2.00||2.00|
|(P) Phosphorus, max||0.045||0.045||0.045|
|(S) Sulfur, max||0.030||0.030||0.030|
|(Ti) Titaniu||N/A||N/A||5xC - 0.070|
min, ksi (Mpa)
min, ksi (Mpa
|Elong. In 2"
|304L||70 (485)||25 (170||40|
|316L||70 (485)||25 (170)||40|
|321||75 (515)||30 (205)||40|
|Reverse Bend||Not Required||Required|
|Eddy Current Transverse||Not Required||Required|
Designation: A 778 – 01
Standard Specification for
Welded, Unannealed Austenitic Stainless Steel Tubular
This standard is issued under the fixed designation A 778; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1.1 This specification covers straight seam and spiral butt
seam welded unannealed austenitic stainless steel tubular
products intended for low and moderate temperatures and
corrosive service where heat treatment is not necessary for
corrosion resistance. Table 1 lists the five grades covered by
this specification. The user of this specification should be
aware that a minimum amount of testing and examination is
required of the basic product. The user requiring additional
testing or examination is referred to the supplemental requirements
or Ordering Information, or both. Users requiring a
tubular product with post-weld heat treatment or with radiographic
examination are referred to Specification A 312/
A 312M, A 358/A 358M, or A 409/A 409M, as applicable.
1.2 This specification covers welded unannealed tubular
products 3 in. (75 mm) through 48 in. (1200 mm) in outside
diameter and in nominal wall thicknesses of 0.062 in. (1.5 mm)
through 0.500 in. (12.5 mm) produced to this specification.
Tubular products having other diameters or wall thickness, or
both, may be furnished provided it complies with all other
requirements of this specification.
1.3 The values stated in inch-pound units are to be regarded
as the standard.
2. Referenced Documents
2.1 ASTM Standards:
A 240 Specification for Heat-Resisting Chromium and
Chromium-Nickel Stainless Steel Plate, Sheet, and Strip
for Pressure Vessels2
A 262 Practices for Detecting Susceptibility to Intergranular
Attack in Austenitic Stainless Steels2
A 312/A 312M Specification for Seamless and Welded
Austenitic Stainless Steel Pipes3
A 358/A 358M Specification for Electric-Fusion-Welded
Austenitic Chromium-Nickel Alloy Steel Pipe for High-
1 This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel, and Related Alloys and is the direct responsibility of Subcommittee
A01.10 on Stainless and Alloy Steel Tubular Products.
Current edition approved Mar. 10, 2001. Published June 2001. Originally
published as A 778 – 80. Last previous edition A 778 – 00.
2 Annual Book of ASTM Standards, Vol 01.03.
3 Annual Book of ASTM Standards, Vol 01.01.
A 370 Test Methods and Definitions for Mechanical Testing
of Steel Products2
A 409/A 409M Specification for Welded Large Diameter
Austenitic Steel Pipe for Corrosive or High-Temperature
A 700 Practices for Packaging, Marking, and Loading
Methods for Steel Products for Domestic Shipment4
A 941 Terminology Relating to Steel, Related Alloys, and
A 999/A 999M Specification for General Requirements for
Alloy and Stainless Steel Pipe3
E 340 Test Method for Macroetching Metals and Alloys5
E 527 Practice for Numbering Metals and Alloys (UNS)3
2.2 AWS Standards:
A 5.4 Corrosion—Resisting Chromium and Chromium-
Nickel Steel Covered Welding Electrodes6
A 5.9 Corrosion–Resisting Chromium and Chromium-
Nickel Steel Welding Rods and Bare Electrodes6
2.3 SAE Standard:
SAE J1086 Practice for Numbering Metals and Alloys
3.2 The definitions in Specification A 999/A 999M and
Terminology A 941 are applicable to this specification.
4. Ordering Information
4.1 Orders for material to this specification should include
4.1.1 Quantity (feet, metres, or number of pieces),
4.1.2 Name of material (welded unannealed austenitic stainless
steel tubular products),
4.1.3 Straight seam or spiral butt seam,
4.1.4 Grade (see Table 1),
4.1.5 Size (outside diameter and specified wall thickness)
(see 10.3 and 10.4),
4 Annual Book of ASTM Standards, Vol 01.05.
5 Annual Book of ASTM Standards, Vol 03.01.
6 Available from American Welding Society, 2501 N.W. 7th St., Miami, FL
7 Available from Society of Automotive Engineers, 400 Commonwealth Drive,
Warrendale, PA 15096.
4.1.6 Length (mill standard lengths, or specify cut lengths)
4.1.7 Optional requirements (Supplementary Requirements
S1 to S5),
4.1.8 Certification requirements,
4.1.9 Specification designation, and
4.1.10 Special requirements.
5. Significance and Use
5.1 It is anticipated that the ASTM Subcommittees A01.06,
A01.10, A01.17, A01.22, and A01.28 will use the standard
composition limits listed in this specification for the grades
identified by the corresponding UNS designation in the product
specification unless there is a specific technical justification for
doing otherwise. The compositions in this specification shall
not be considered as chemical requirements for any particular
product until adopted by the subcommittee overseeing that
6.1 The tubular products shall be made from flat-rolled steel
sheet, coil, or plate by a shielded arc-welding process. The
material used for manufacture shall conform to the requirements
of one of the grades of Specification A 240 listed in
Table 1. At the manufacturer’s option, filler metal may be used.
6.2 Tubular products 14 in. (350 mm) in diameter and
smaller shall have a single longitudinal weld or a spiral butt
weld seam. Tubular products of larger diameter may have a
maximum of three longitudinal welds. All weld tests, examinations,
inspections, or treatments are to be performed on each
6.3 Circumferentially welded joints of the same quality as
the longitudinal or spiral joints shall be permitted by agreement
between the manufacturer and the purchaser.
6.4 All tubular products shall be furnished clean and free of
6.5.1 The welds shall be made by the manual or automatic
6.5.2 The welded joints may show a reinforcing bead no
greater than 1⁄16 in. (1.6 mm) on either surface of the tubular
product. At no place shall the thickness of the weld section be
less than the minimum wall thickness permitted by the tolerances
of 10.4. The weld bead may be removed at the option of
the manufacturer or upon agreement between the manufacturer
6.5.3 Injurious weld defects shall be repaired by removal to
sound metal and rewelding.
6.5.4 The alloy content (chromium, nickel, molybdenum,
columbium, and carbon) of the filler metal shall conform to
that required for the plate or the welding electrodes as shown
in Table II of Specification AWS A5.4 or in Table I of
Specification AWS A5.9, except that when welding on Type
321 base metal, the deposited weld metal may correspond to
7. Mechanical Test Requirements
7.1 Each lot shall be subjected to one transverse tension test
and two transverse guided bend tests.
NOTE 1—The term lot applies to all pipe of the same grade, of the same
thickness, produced from the same heat with the same weld procedure.
7.2 The maximum lot size shall be in accordance with the
Lot Size (lengths)
up to 3 in. exclusive
3–8 in. exclusive
8–14 in. exclusive
14 in. and over
7.3 Specimen Preparation:
7.3.1 Transverse tension and bend test specimens shall be
taken from the end of a length and shall be flattened cold before
final machining to size.
7.3.2 As an alternative to the requirements of 7.3.1, the test
specimens may be taken from test plates of the same material
as the tube, which are attached to the end of the cylinder and
welded as a prolongation of the tube longitudinal weld.
7.3.3 Tension test specimens shall be made in accordance
with Test Methods and Definitions A 370.
7.4 Transverse Tension Test:
7.4.1 Transverse tension tests taken transversely across the
welded joint shall meet the same minimum tensile strength as
the base material (Table 2).
7.4.2 When diameters below 8-in. (200 mm) make it impractical
to perform a transverse tension test, an alternative test
may be permitted by agreement between the manufacturer and
7.5 Transverse Guided—Bend Weld Test:
TABLE 2 Tensile Requirements
TABLE 2 Tensile Requirements
7.5.1 Take two bend test specimens transversely from the
weld. Subject one to a face guided-bend test and the second to
a root guided-bend test. Bend one specimen with the inside
surface of the tube against the plunger, and the other with the
outside surface against the plunger.
7.5.2 The bend test shall be acceptable if no cracks or other
defects exceeding 1⁄8 in. (3 mm) in any direction are present in
the weld metal or between the weld and the parent metal after
bending. Cracks that originate along the edges of the specimen
during testing, and that are less than 1⁄4 in. (6 mm) measured in
any direction shall not be considered.
7.5.3 Make and test transverse guided-bend weld test specimens
in accordance with Test Methods and Definitions A 370.
7.5.4 When diameters below 8 in. (200 mm) make it
impractical to perform a transverse guided-bend test, a flattening
test may be substituted (see Supplementary Requirement
8. Heat Treatment
8.1 Heat treatment shall not be required.
9. Chemical Requirements
9.1 Mill certificates of heat analysis of each heat of steel
shall be furnished upon request.
10. Permissible Variations in Tubular Products
10.1 Lengths—Tubular products are normally furnished in
mill lengths 10 ft (3 m) and over. If specific lengths are
ordered, no length shall be under the length specified and not
more than 1⁄4 in. (6 mm) over that specified.
10.2 Straightness—Using a 10-ft (3-m) straightedge placed
so that both ends are in contact with the length, a maximum of
a 0.25-in. (6-mm) gap is allowable.
10.3 Diameter Tolerance—Refer to the applicable table in
Specification A 999/A 999M.
10.4 Wall Thickness—Wall thickness tolerance shall be
11.1 Finished products shall have smooth ends free of burrs.
Tubular products shall be free of injurious defects and shall
have a workmanlike finish. Surface imperfections, such as
handling marks, straightening marks, light mandrel and die
marks, shallow pits, and scale patterns, will not be considered
as serious defects, provided the imperfections are removable
within the allowable wall thickness tolerance. The removal of
surface imperfections is not required.
12.1 The inspector representing the purchaser shall have
entry at all times while work on the contract of the purchaser
is being performed, to all parts of the manufacturer’s works
that concern the manufacture of the material ordered. The
manufacturer shall afford the inspector all reasonable facilities
to satisfy him that the material is being furnished in accordance
with this specification. All required tests and inspections shall
be made at the place of manufacture prior to shipment, unless
otherwise specified, and shall be conducted so as not to
interfere unnecessarily with the operation of the works.
13.1 Each length of tube received from the manufacturer
may be inspected by the purchaser. If it does not meet the
requirements of this specification based on the inspection and
test method as outlined, the length may be rejected and the
manufacturer shall be notified. Disposition of rejected lengths
shall be a matter of agreement between the manufacturer and
14.1 A certification that the material conforms to the requirements
of this specification shall be the basis of acceptance
of the material. When requested by the purchaser, the manufacturer
shall report to the purchaser or his representative the
results of any supplemental test requirements.
15. Product Marking
15.1 Each length of tube shall be legibly marked with the
manufacturer’s name or brand, specified size, heat number, this
specification number, grade of material, and the letters HT-O to
indicate that the pipe was not heat treated.
15.2 For small-diameter tubes and pieces under 3 ft (0.90 m)
in length, the information specified in 15.1 shall be marked on
a tag securely attached to the bundle or box in which the pieces
16.1 Tubular products may be shipped loose. The manufacturer
may, at his option, box, crate, or package in secure lifts or
bundles to ensure safe delivery as specified in Practices A 700.
17.1 austenitic stainless steel; stainless steel tubing; steel
tubing; welded steel tubing
One or more of the following supplementary requirements may be included in the purchaser’s
inquiry or in the order or contract. When so included, a supplementary requirement shall have the
same force as if it were in the body of the specification. Details of a supplementary requirement shall
be agreed to between the manufacturer and the purchaser.
S1. Etching Tests
S1.1 An etching test, when specified, shall be made on a
transverse section from one end of one length from each 2500
ft (760 m) or fraction thereof from each heat of steel or as
specified by the purchaser. An etching test in accordance with
Test Method E 340 shall be made. The test shall show sound,
homogeneous, and reasonable uniform material, free of injurious
laminations, cracks, and similar objectionable defects. If
the specimen of any length shows objectional defects, one
retest shall be permitted from the same end. If this fails, the
length shall be rejected.
S2. Intergranular Corrosion Bend Test
S2.1 One intergranular corrosion bend test shall be made on
a welded section from one end of one length from each 2500
ft (760 m) or fraction thereof from each heat of steel or as
specified by the purchaser. The specimen shall be bent so that
the location of weld is at the point of maximum bend. The
method of testing shall be in accordance with Practice E of
Practices A 262.
S3. Packaging Requirements
S3.1 The ends shall be protected with wooden or plastic
S4. Hydrostatic Test
S4.1 Each length shall be subjected to a hydrostatic test in
accordance with Specification A 999/A 999M, section on Hydrostatic
S5. Flattening Test
S5.1 One flattening test shall be made to represent each lot
(see Note 1) of finished product. Crop ends may be used.
S5.2 Evidence of laminated or unsound material that is
revealed during the flattening test shall be cause for rejection.
S5.3 Superficial ruptures resulting from surface imperfections
shall not be cause for rejection.
S5.4 A section of welded pipe not less than 4 in. (100 mm)
in length shall be flattened cold between parallel plates in two
steps. The weld shall be placed 90° from the direction of the
applied force. During the first step, which is a test for ductility,
no cracks or breaks on the inside or outside surfaces shall occur
until the distance between the plates is less than one half of the
outside diameter of the pipe. During the second step, which is
a test for soundness, the flattening shall be continued until the
specimen breaks or the opposite walls of the pipe meet.