ASTM A686 Norms for Tool Steel, Carbon

ASTM A 686 Tool Steel, Carbon Steel

Hot Rolled Flat Bars Width and Thickness Tolerances Width Tolerances A

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Specified Widths, in. (mm) Width Tolerances, in. (mm)
Under Over
To 1 (25.4), incl 0.016 (0.41) 0.031 (0.79)
Over 1 to 3 (25.4 to 76), incl 0.031 (0.79) 0.047 (1.19)
Over 3 to 5 (76 to 127), incl 0.047 (1.19) 0.063 (1.60)
Over 5 to 7 (127 to 178), incl 0.063 (1.60) 0.094 (2.39)
Over 7 to 10 (178-254), incl 0.078 (1.98) 0.125 (3.18)
Over 10 to 12 (254-305), incl 0.094 (2.39) 0.156 (3.96)


Cold Drawn Bars Rounds, Octagons, Quarter Octagons and Hexagons Size Tolerances A


Cold Drawn Square and Flat Bars Size Tolerances A
Size Range, in. (mm) Tolerance, in. (mm)
Plus and Minus
1⁄4 to 1⁄2 (6.4 to 12.7), excl 0.002 (0.05)
1⁄2 to 1 (12.7 to 25.4), excl 0.0025 (0.06)
1 to 23⁄4 (25.4 to 69.8), incl 0.003 (0.08)
A Out of section tolerance to be ½ the total tolerance max.
Size Range, in. (mm) Tolerance, in. (mm) ±
1⁄4 to 3⁄4 (6.4 to 19.1), incl 0.002 (0.05)
Over 3⁄4 to 11⁄2 (19.1 to 38.1), incl 0.003 (0.08)
Over 11⁄2 (38.1) 0.004 (0.10)
A Out of square tolerance to be ½ total tolerance max.


Centerless Ground Bars Rounds Diameter Tolerances A

Diameter Range, in. (mm)

Tolerance, in. (mm)
Under Over
1⁄4 to 1⁄2 (6.4 to 12.7), excl 0.0015 (0.038) 0.0015 (0.038)
1⁄2 to 31⁄16 (12.7 to 77.8), excl 0.002 (0.05) 0.002 (0.05)
31⁄16 to 41⁄16 (77.8 to 103.2), incl 0.003 (0.08) 0.003 (0.08)
A Out of round tolerance to be ½ of the total tolerance, max.


Forged Bars Rounds, Squares, Octagons, Hexagons Size Tolerances A

Specified Sizes, in. (mm)

Size Tolerances, in. (mm)
Under Over
Over 1 to 2 (25.4 to 50.8), incl 0.030 (0.76) 0.060 (1.52)
Over 2 to 3 (50.8 to 76), incl 0.030 (0.76) 0.080 (2.03)
Over 3 to 5 (76 to 127), incl 0.060 (1.52) 0.125 (3.18)
Over 5 to 7 (127 to 177.8), incl 0.125 (3.18) 0.187 (4.75)
Over 7 to 9 (178 to 229), incl 0.187 (4.75) 0.312 (7.92)
A Out of section tolerance to be ¾ of total tolerance max.


Forged Flat Bars Width Tolerances A

Specified Widths, in. (mm) Width Tolerances, in. (mm)
Under Over
Over 1 to 3 (25.4 to 76), incl 0.031 (0.79) 0.078 (1.98)
Over 3 to 5 (76 to 127), incl 0.062 (1.57) 0.125 (3.18)
Over 5 to 7 (127 to 178), incl 0.125 (3.18) 0.187 (4.75)
Over 7 to 9 (178 to 229), incl 0.187 (4.75) 0.312 (7.92)


Drill Rod Rounds, Polished or Ground Size Tolerances A

Size Range, in. (mm) Standard Manufacturing
Tolerance, in. (mm), ±		 Precision
Tolerance, in. (mm), ±
Up to 0.124 (3.15),incl 0.0003 (0.008) 0.0002 (0.005)
0.125 to 0.499 (3.18 to 12.7), incl 0.0005 (0.013) 0.00025 (0.006)
0.500 to 1.500 (12.7 to 38.1), incl 0.001 (0.03) 0.0005 (0.013)
A Out of round tolerance to be ½ the total tolerance.


Hot Rolled Plates and Sheets Tolerances for Width and Thickness

Thickness, in. (mm) Width, in. (mm)

Up to 15 (381)

 Over 15 (381)
All tolerances over specified width and specified thickness, in. (mm)
Width Thickness Width Thickness
Up to 0.025, (0.64), incl 1⁄8 (3.2) 0.006 (0.15) 3⁄16 (4.8) 0.006 (0.15)
Over 0.025 to 0.065, (0.64 to 1.65), incl 1⁄8 (3.2) 0.008 (0.20) 3⁄16 (4.8) 0.008 (0.20)
Over 0.065 to 0.120, (1.65 to 3.05), incl 1⁄8 (3.2) 0.010 (0.25) 3⁄16 (4.8) 0.010 (0.25)
Over 0.120 to 0.1875, (3.05 to 4.76), incl 3⁄16 (4.8) 0.016 (0.41) 1⁄4 (6.4) 0.016 (0.41)
Over 0.1875 to 0.250, (4.76 to 6.35), incl 3⁄16 (4.8) 0.018 (0.46) 1⁄4 (6.4) 0.018 (0.46)
Thickness, in. (mm) Width, in. (mm)
Over 12 (305)
All tolerances over specified width and specified thickness, in. (mm)
Width Thickness
1⁄4 to 1⁄2 (6.4 to 12.7), incl ¼ (6.4) 1⁄16 (1.6)
Over 1⁄2 to 2 (12.7 to 50.8), incl ¼ (6.4) 1⁄8 (3.2)
Over 2 (50.8) ¼ (6.4) 1⁄4 (6.4)

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