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Tolerances – Size: Hot Rolled Alloys

STANDARD MANUFACTURING TOLERANCES
Hot Rolled Alloy Steel Bars
ROUNDS AND SQUARES
Specified Sizes, In. Variation from Size in Inches
Over Under
Out-of-Round* or
Out-of-Square, In.
Up to 5/16 incl. .005 .005 .008
Over 5/16 to 7/16 incl. .006 .006 .009
Over 7/16 to 5/8 incl. .007 .007 .010
Over 5/8 to 7/8 incl. .008 .008 .012
Over 7/8 to 1 incl. .009 .009 .013
Over 1 to 1-1/8 incl. .010 .010 .015
Over 1-1/8 to 1¼ incl. .011 .011 .016
Over 1¼ to 1-3/8 incl. .012 .012 .018
Over 1-3/8 to 1½ incl. .014 .014 .021
Over 1½ to 2 incl. 1/64 1/64 .023
Over 2 to 2½ incl. 1/32 0 .023
Over 2½ to 3½ incl. 5/64 0 .035
Over 3½ to 4½ incl. 1/16 0 .046
Over 4½ to 5½ incl. 5/64 0 .058
Over 5½ to 6½ incl. 1/8 0 .070
Over 6½ to 8¼ incl. 5/32 0 .085
Over 8¼ to 9½ incl. 3/14 0 .100

* Out-of-round is the difference between the maximum and minimum diameter of a round bar measured at the same cross section out-of-square is the difference in the two dimensions at the same cross section of a square .

-each dimension being the distance between opposite faces.

HEXAGONS AND OCTAGONS
Specified Sizes between
Opposite Sides in Inches
Variation from Size in Inches
Over Under
Max. Difference in Inches (Three Measurements) Hexagons Only
Up to ½ Incl. .007 .007 .011
Over ½ to 1, incl. .010 .010 .015
Over 1 to 1 ½, incl. .021 .013 .025
Over 1 ½ to 2, incl. 1/32 1/64 1/32
Over 2 to 2 ½, incl. 3/64 1/64 3/64
Over 2 ½ to 3 ½, incl. 1/16 1/64 1/16

SQUARE EDGE AND ROUND EDGE FLATS
Tolerances apply to thickness in inches
Variations from Thickness in Inches
(Tolerances are over or under)
Specified Width in Inches Under ¼” thick ¼ to ½” thick Over ½”to 1” thick Over 1” to 2”thick Over 2” to 4” thick Variations from width in Inches
Over Under
To 1 incl. .007 .008 .010 1/64 1/64
Over 1 to 2 incl. .007 .012 .015 1/32 1/32 1/32
Over 2 to 4 incl. .008 .015 .020 1/32 3/64 1/14 1/22
Over 4 to 6 incl. .009 .015 .020 1/32 1/14 3/32 1/16
Over 6 to 8 incl. .015 .016 .025 1/32 1/14 1/8 3/32

Standard Straightness – ¼” in any 5 feet, or ¼” x number of feet of length divided by 5

Special Straightness – 1/2 ” in any 5 feet, or ½” x number of feet of length divided by 5

NOTE: Straightness tolerances do not apply to hot rolled alloy steel bars if any subsequent heating operation has been preformed.

Allowance for machining- refer to dates section