(a) Tensile test. - Test
pieces cut from the ends of the selected pipes shall comply
with the following requirements.
The tensile test may be carried out on the test pieces
cut out from the pipe in the longitudinal direction which
shall not be further heat treated nor straightened within the
As an alternative, pipes may be tested on full cross
Strength Mpa (kg/mm2)
for full tube testing
longitudinal strip test, the minimum required elongation shall
be determined by the following equation.
= 1944 (A 0.2/U0.9)
e = minimum elongation in 50.8 mm, % rounded to the
= cross sectional area of the tensile test specimen in mm2
based on specified outside diameter or nominal specimen width
and specified wall thickness rounded to the nearest 6.45 mm2.
If the area thus calculated is more than 484 mm2
then use area as 484 mm2.
If the calculated area is less than 484mm2
then use the actual area thus obtained.
U = specified tensile strength in Mpa.
(b) Bend test. - For pipes of outside diameter 60.3 mm and under, a
bend test shall be conducted.
A sufficient length of pipe shall stand being bent cold
through 90 degree around a cylindrical mandrel, the diameter
of which is 12 times the nominal diameter of the pipe, without
(c) Flattening test. - (i) For
pipes of outside diameter over 60.3 mm, a flattening test
shall be conducted.
A section of the pipe not less than 63 mm in length
shall be flattened cold between two parallel flat surfaces to
a distance between the plates (H) as calculated by the formula
given below, without showing any sign of a crack or flaw.
(1 + e) t
e + t/D
t = specified thickness of pipe (mm)
D = specified outside diameter of the pipe (mm)
e = a constant, as given below
= 0.07 for carbon steel with maximum specified carbon 0.19% or
= 0.09 for carbon steel with maximum specified carbon 0.18% or
For pipe whose diameter equals or exceeds 254 mm, a
bend test may be conducted instead of the flattening test.
The bend test specimens shall be bent at room
temperature through 180 degree without cracking on the outside
of the bent portion.
The inside diameter of the bend shall be 25 mm.
Substitution of the bend test for the flattening test
shall be subject to the approval of the purchaser.
For pipe whose diameter exceeds 635 mm and whose
diameter to wall thickness ratio is 7.0 or less, the bend test
described in clause (b) shall be conducted instead of the