Las necesidades de material

11.6.2 Due to the specimen geometry effect encountered

when using full-section test specimens for angles, the elongation

requirements for structural-size angles shall be increased

by six percentage points when full-section test specimens are

used.

11.6.3 Due to the inherently lower elongation that is obtainable

in thicker material, adjustments in elongation requirements

must be provided. For material over 3.5 in. [90 mm] in

thickness, a deduction of 0.5 percentage point from the

specified percentage of elongation in 2 in. [50 mm] shall be

made for each 0.5–in. [12.5–mm] increment of thickness over

3.5 in. [90 mm]. This deduction shall not exceed 3 percentage

points. Accordingly, the following deductions from the base

elongation requirements shall apply:

Nominal Thickness Range,

in. [mm]

Elongation

Deduction,%

3.500—3.999 [90.00—102.49] 0.5

4.000—4.499 [102.50—114.99] 1.0

4.500—4.999 [115.00—127.49] 1.5

5.000—5.499 [127.50—139.99] 2.0

5.500—5.999 [140.00—152.49] 2.5

6.000 and thicker [152.50 and thicker] 3.0

11.6.4 When so stated in the material specification, for

plates up to 3⁄4 in. [20 mm], inclusive, in thickness, if the

percentage of elongation of an 8-in. [200-mm] gage length test

specimen falls not more than 3 percentage points below the

amount prescribed, the elongation shall be considered satisfactory,

provided the percentage of elongation in 2 in. [50 mm]

across the break is not less than 25 %.

NOTE 5—A characteristic of certain types of alloy steels is a local

disproportionate increase in the degree of necking down or contraction of

the specimens under tension test, resulting in a decrease in the percentage

of elongation as the gage length is increased. The effect is not so

pronounced in the thicker plates.

11.6.5 The tensile property requirements tables in many of

the material specifications covered by this general specification

specify elongation requirements in both 8-in. [200–mm] and

2-in. [50–mm] gage lengths. Unless otherwise provided in the

individual material specification, both requirements are not

required to be applied simultaneously and elongation need only

be determined in gage length appropriate for the test specimen

used. After selection of the appropriate gage length, the

elongation requirement for the alternative gage length shall be

deemed not applicable.

11.7 Yield Strength Application:

11.7.1 When test specimens do not exhibit a well-defined

disproportionate yield point, yield strength shall be determined

and substituted for yield point.

11.7.2 The manufacturer or processor shall have the option

of substituting yield strength for yield point if the test specimen

exhibits a well-defined disproportionate yield point.

11.7.3 Yield strength shall be determined either by the

0.2 % offset method or by the 0.5 % extension-under-load

method.

11.8 Product Tension Tests—This specification does not

provide requirements for product tension testing subsequent to

shipment (see 15.1). Therefore, the requirements of 11.1 to11.7

inclusive and Section 13 apply only for tests conducted at the

place of manufacture prior to shipment.

NOTE 6—Compliance to Specification A 6/A 6M and the individual

material specifications by a manufacturer does not preclude the possibility

that product tension test results might vary outside specified ranges. The

tensile properties will vary within the same heat or piece, be it as-rolled,

control-rolled, or heat-treated. Tension testing according to the requirements

of Specification A 6/A 6M does not provide assurance that all

products of a heat will be identical in tensile properties with the products

tested. If the purchaser wishes to have more confidence than that provided

by Specification A 6/A 6M testing procedures, additional testing or

requirements, such as Supplementary Requirement S4, should be imposed.

11.8.1 Appendix X2 provides additional information on the

variability of tensile properties in plates and structural shapes

12. Permitted Variations in Dimensions and Weight

[Mass]

12.1 One cubic foot of rolled steel is assumed to weigh 490

lb. One cubic metre of rolled steel is assumed to have a mass

of 7850 kg.

12.2 Plates—The permitted variations for dimensions and

weight [mass] shall not exceed the applicable limits in Tables

1 to 15 [Annex A1, Tables A1.1 to A1.15], inclusive.

12.3 Shapes:

12.3.1 Annex A2 lists the designations and dimensions, in

both inch-pound and SI units, of shapes that are most commonly

available. Radii of fillets and toes of shape profiles vary

with individual manufacturers and therefore are not specified.

12.3.2 The permitted variations in dimensions shall not

exceed the applicable limits in Tables 16 to 25 [Annex A1,

Tables A1.16 to A1.25], inclusive. Permitted variations for

special shapes not listed in such tables shall be as agreed upon

between the manufacturer and the purchaser.

NOTE 7—Permitted variations are given in Tables 16 to 25 [Annex A1,

Tables A1.16 to A1.25], inclusive, for some shapes that are not listed in

Annex A2 (that is, bulb angles, tees, zees). Addition of such sections to

Annex A2 will be considered by Subcommittee A01.02 when and if a need

for such listing is shown.

12.3.3 Shapes Having One Dimension of the Cross Section

3 in. [75 mm] or Greater (Structural-Size Shapes)—The

cross-sectional area or weight [mass] of each shape shall not

vary more than 2.5 % from the theoretical or specified

amounts.

12.4 Sheet Piling—The weight [mass] of each steel sheet

pile shall not vary more than 2.5 % from the theoretical or

specified weight [mass]. The length of each steel sheet pile

shall be not less than the specified length, and not more than 5

in. [125 mm] over the specified length..

12.5 Hot-Rolled Bars—The permitted variations in dimensions

shall not exceed the applicable limits in Tables 26 to 31

[Annex A1, Tables A1.26 to A1.31], inclusive.

13. Retests

13.1 If any test specimen shows defective machining or

A 6/A 6M

12

develops flaws, the manufacturer or processor shall have the

option of discarding it and substituting another test specimen.

13.2 If the percentage of elongation of any tension test

specimen is less than that specified and any part of the fracture

is more than 3⁄4 in. [20 mm] from the center of the gage length

of a 2-in. [50-mm] specimen or is outside the middle half of the

gage length of an 8-in. [200-mm] specimen, as indicated by

scribe scratches marked on the specimen before testing, a retest

shall be allowed.

13.3 Except as provided in 13.3.1, if the results from an

original tension specimen fails to meet the specified requirements,

but are within 2 ksi [14 MPa] of the required tensile

strength, within 1 ksi [7 MPa] of the required yield strength or

yield point, or within 2 percentage points of the required

elongation, a retest shall be permitted to replace the failing test.

A retest shall be performed for the failing original test, with the

specimen being randomly selected from the heat. If the results

of the retest meet the specified requirements, the heat or lot

shall be approved.

13.3.1 For structural products produced from coils, both

tests from each coil tested to qualify a heat are required to meet

all mechanical property requirements. Should either test fail to

do so, then that coil cannot be used to qualify the parent heat,

however, the portion of that individual coil that is bracketed by

acceptable tests (see 11.4.2.3) is considered to be qualified.

13.4 Quenched and tempered steel plates are subject to the

additional retest requirements contained in the material specification.

13.5 When the full-section option of 11.3.3 is used and the

elongation falls below the specified requirement, the manufacturer

or processor shall have the option of making another test

using a test specimen permitted in 11.5.2.

14. Test Reports

14.1 Test reports for each heat supplied are required and

they shall report the following:

14.1.1 The specification designation, including year of issue,

and the grade or class if applicable, to which the material

is furnished.

14.1.2 The heat number, heat analysis (see 7.1), and nominal

sizes.

NOTE 8—If the amount of copper, chromium, nickel, molybdenum, or

silicon is less than 0.02 %, the heat analysis for that element may be

reported as <0.02 %. If the amount of columbium or vanadium is less than

0.008 %, the heat analysis for that element may be reported as <0.008%.

14.1.3 Two tension test results appropriate to qualify the

material shipped (see 11.4), except that only one test result

need be reported if the shipment

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