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1. Designation: A860/A860M14

for Wrought High-Strength Ferritic Steel Butt-Welding Fittings



2.  Chemical Requirements  (Composition%)

Carbon                  0.20A

Manganese            1.00–1.45       All values are

Phosphorus             0.030          maximum unless 

Sulfur                  0.010        a range is stated

Silicon                0.15–0.40B 

Nickel                   0.50C 

Chromium               0.30C 

Molybdenum            0.25C 

Copper                 0.35C 

Titanium                0.05

Vanadium               0.10


AThe carbon equivalent,as calculated by the following formula,shall not exceed 0.42%:

B If vacuum carbon deoxidation isused,silicon shall not exceed 0.10% by heat analysis and 0.12% by product analysis.

CThe sum of Ni+Cr+Mo+Cu shal lnot exceed 1.0%.



3 Mechanical Requirements

Property                                              Grade


Yield strength,minA 0.2% offset, ksi[MPa]                  52[360]

Tensile strength, ksi[MPa]                               66[455]

Elongation: implements A860/A860M–10 standard.

3.2 One set of impact tests(three specimens) shall be made to represent the base metal and one set(three specimens) to represent the weld metal on the same frequency as the tension tests.

3.3 The test temperature shall be -50°F[-46°C].



4. Hardness Requirements

Shall have a maximum hardness of 22HRC (235HBW).




5.1 Dimensional requirements for NPS14 and smaller are provided in ASMEB16.9.

5.2 Dimensional requirements for elbows larger than NPS14 through NPS48 are provided by MSS-SP-75.

5.3 Fittings that do not have a thickness or yield strength,or both,that are equal to the mating pipe,are acceptable 

Provided the welding end preparations comply with MSS-SP-75,Figs.3(a),(b),and(c)and the fitting welding-end thickness Is at least equal to the pipe wall thickness times the ratio of the specified minimum yield strength of the pipe and the minimum tested yield strength of the fitting.



6.Workmanship, Finish and Appearance

12.1 The wall thickness at all points shall be at least 931/2 % of the specified nominal wall thickness,and the diameters at all points shall be within the Specified limits.

12.2 When the removal of a surface discontinuity reduces the wall thickness below 931/2 % of the specified nominal wall thickness at any point;



7. HydrostaticTest

The hydrostatic pressure shall be calculated in accordance with Barlow’s equation:

            P = 2ST / D


P = hydrostatic pressure,

S =specific yield strength,min,

T =nominal wall thickness,and

D =outside diameter.

Steel grade: when D≤219, select 75%; when D> 219 to <508, select 85%; when D≥508mm, select 90%; when

D≤457mm, hold time should not be less than 5S.

When D> 457mm, the pressure holding time shall not be less than 10S.

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