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Alloy Steel Tolerances

 

Round Bars | Square Bars | Hex Bars | Rectangle Bars | Sheet/Plate | Round Tubes | Balls

 

 

 

 

 

 

 

Round Bar
Alloy(s)   Spec. Diameter, in. Diameter Tol. (over(+)/under(-))
4130-Norm., 4140-Ann., 4340-Norm. Cold Finish  Up to 1.5, incl.  +/- 0.004"
4130-Norm., 4140-Ann. Cold Finish  Over 1.5 to 2.5, incl.  +/- 0.005"
4130-Norm., 4140-Ann. Cold Finish  Over 2.5 to 4, incl.  +/- 0.006"
4130-Norm. Cold Finish  Over 4 to 6, incl.  +/- 0.007"

 

 

Round Bar
Alloy(s)   Spec. Diameter, in. Diameter Tol. (over(+)/under(-))
8620 Cold Finish  Up to 1.5, incl.  +/- 0.003"
8620 Cold Finish  Over 1.5 to 2.5, incl.  +/- 0.004"
8620 Cold Finish  Over 2.5 to 4, incl.  +/- 0.005"

 

 

Round Bar
Alloy(s)   Spec. Diameter, in. Diameter Tol. (over(+)/under(-))
4340-Norm. Hot Rolled/ Rough Turned  Over 1 to 1.125, incl.  +/- 0.010"
4340-Norm. Hot Rolled/ Rough Turned  Over 1.125 to 1.25, incl.  +/- 0.011"
4340-Norm. Hot Rolled/ Rough Turned  Over 1.25 to 1.375, incl.  +/- 0.012"
4340-Norm. Hot Rolled/ Rough Turned  Over 1.375 to 1.5, incl.  +/- 0.014"
4340-Norm., 8620 Hot Rolled/ Rough Turned  Over 1.5 to 2, incl.  +/- 0.015625"
4340-Norm., 8620 Hot Rolled/ Rough Turned  Over 2 to 2.5, incl.  + 0.03125"
4340-Norm., 8620 Hot Rolled/ Rough Turned  Over 2.5 to 3.5, incl.  + 0.046875"
4340-Norm., 8620 Hot Rolled/ Rough Turned  Over 3.5 to 4.5, incl.  + 0.0625"
4340-Norm., 8620 Hot Rolled/ Rough Turned  Over 4.5 to 5.5, incl.  + 0.078125"
4340-Norm., 8620 Hot Rolled/ Rough Turned  Over 5.5 to 6.5, incl.  + 0.125"
4340-Norm. Hot Rolled/ Rough Turned  Over 6.5 to 8.25, incl.  + 0.15625"
4340-Norm. Hot Rolled/ Rough Turned  Over 8.25 to 9.5, incl.  + 0.1875"

 

 

Round Bar
Alloy(s)   Spec. Diameter, in. Diameter Tol. (over(+)/under(-))
4330, 4340, 9310 VAR  Up to 0.3125  +/- 0.005"
4330, 4340, 9310 VAR  Over 0.3125 to 0.4375, incl.  +/- 0.006"
4330, 4340, 9310 VAR  Over 0.4375 to 0.625, incl.  +/- 0.007"
4330, 4340, 9310 VAR  Over 0.625 to 0.875, incl.  +/- 0.008"
4330, 4340, 9310 VAR  Over 0.875 to 1.000, incl.  +/- 0.009"
4330, 4340, 9310 VAR  Over 1.000 to 1.125, incl.  +/- 0.010"
4330, 4340, 9310 VAR  Over 1.125 to 1.250, incl.  +/- 0.011"
4330, 4340, 9310 VAR  Over 1.250 to 1.375, incl.  +/- 0.012"
4330, 4340, 9310 VAR  Over 1.375 to 1.500, incl.  +/- 0.014"
4330, 4340, 9310 VAR  Over 1.500 to 2.000, incl.  +/- 0.016"
4330, 4340, 9310 VAR  Over 2.000 to 2.500, incl.  + 0.031"
4330, 4340, 9310 VAR  Over 2.500 to 3.500, incl.  + 0.047"
4330, 4340, 9310 VAR  Over 3.500 to 4.500, incl.  + 0.063"
4330, 4340, 9310 VAR  Over 4.500 to 5.500, incl.  + 0.078"
4330, 4340, 9310 VAR  Over 5.500 to 6.500, incl.  + 0.125"
4330, 4340, 9310 VAR  Over 6.500 to 8.250, incl.  + 0.156"
4330, 4340, 9310 VAR  Over 8.250 to 9.500, incl.  + 0.188"
4330, 4340, 9310 VAR  Over 9.500 ot 10.000, incl.  + 0.250"

 

 

Metric Round Bar
Alloy(s)   Spec. Dia., mm Dia. Tol. (over(+)/under(-))
4140 metric Ann. TGP 6mm to 42mm + 0/- 0.0005″ (.0127mm)
4140 metric Ann. TGP 45mm to 60mm + 0/- 0.00075″ (.0191mm)

 

 

Straightness Tolerance - Cold Finished Round Bar
Alloy(s)   Spec. Dia., in. Max. Deviation from Straightness
4130, 4140, 4340 Cold Finished Less than 0.625 1/8"
4130, 4140, 4340 Cold Finished 0.625 and over 1/16"
8620 Cold Finished Less than 0.625 3/16"
8620 Cold Finished 0.625 and over 1/8"
Straightness tolerance will be void once full length is cut

 

 

Straightness Tolerance - Hot Rolled Round Bar
Alloy(s)   Permissible Variations from Straight
4130, 4140, 4140/4142 Hot Rolled 0.25" in any 5 ft and (0.25" × length in ft)/5
Straightness tolerance will be void once full length is cut

 

 

 

 

 

 

 

Square Bar
Alloy(s)    Spec. Sq., in.
 Sq. Tol. (over(+)/under(-))  Spec. Length Length Tol. (over(+)/under(-))
4142 Pre- hard All Sizes  +/- 0.001"  18"  + 0.125" to 0.25"
4142 Pre- hard All Sizes  +/- 0.001"  36"  + 0.25" to 0.50"
4142 Pre- hard All Sizes  +/- 0.001"  72"  + 1.00"/- 0"

 

 

 

 

 

 

 

Hex Bar
Alloy(s)   Spec. Across Flats Across Flats Tol. (over(+)/under(-))
4130 Cold Drawn Normalized  Up to 0.500, incl.  +/- 0.007"
4130 Cold Drawn Normalized  Over 0.500 to 1.000, incl.  +/- 0.010"
4130 Cold Drawn Normalized  Over 1.000 to 1.500, incl.  + 0.021"/- 0.013"
4130 Cold Drawn Normalized  Over 1.500 to 2.000, incl.  + 0.03125"/- 0.015625"

 

 

Hex Bar
Alloy(s)   Spec. Across Flats Across Flats Tol. (over(+)/under(-))
4140/4142 Cold Finish  Up to 0.750, incl.  +/- 0.004"
4140/4142 Cold Finish  Over 0.750 to 1.500, incl.   +/- 0.005" 
4140/4142 Cold Finish  Over 1.500 to 2.500, incl.   +/- 0.006" 
4140/4142 Cold Finish  Over 2.500 to 3.125, incl.   +/- 0.007" 

 

 

Metric Hex Bar
Alloy(s)    Spec. Across Flats  Across Flats Tol. (over(+)/under(-))
4140 metric Quench Tempered/ Stress Relieved   > 3mm to ≤ 6mm  + 0/- 0.075mm
4140 metric QT/SR  > 6mm to ≤ 10mm  + 0/- 0.090mm
4140 metric QT/SR  > 10mm to ≤ 18mm  + 0/- 0.110mm
4140 metric QT/SR  > 18mm to ≤ 30mm  + 0/- 0.130mm
4140 metric QT/SR  > 30mm to ≤ 50mm  + 0/- 0.160mm

 

 

Straightness Tolerance - Cold Finished Hex Bar
Alloy(s)   Spec. Dia., in. Max. Deviation from Straightness
4130, 4140, 4140/4142 Cold Finished Less than 0.625 1/8"
4130, 4140, 4140/4142 Cold Finished 0.625 and over 1/16"
Straightness tolerance will be void once full length is cut

 

 

 

 

 

 

 

Rectangle Bar
Alloy(s)    Spec. Thick, in.  Thick Tol. (over(+)/under(-))  Spec. Width, in.  Width Tol. (over(+)/under(-))
 4142  Pre-hard  Any  +/- 0.001"  Any  + 0.000" to + 0.005"

 

 

Rectangle Bar
Alloy(s)   Spec. Width, in.  Width & Thick Tol. (over(+)/under(-))
4340 Cold Drawn  Up to 0.75, incl.  +/- 0.004"
4340 Cold Drawn  Over 0.75 to 1.5, incl.  +/- 0.005"
4340 Cold Drawn  Over 1.5 to 3, incl.  +/- 0.006"
4340 Cold Drawn  Over 3 to 4, incl.  +/- 0.008"
4340 Cold Drawn  Over 4 to 6, incl.  +/- 0.010"

 

 

Rectangle Bar
  Permissible Variations in Thickness, for Thickness Given, in. (over(+)/under(-))  
Alloy(s) Spec. Width, in. 0.230 to 0.250, excl. 0.250 to 0.500, incl. Over 0.500 to 1, incl. Over 1 to 2, incl. Over 2 to 3, incl. Over 3 Width Tol.
4140 HT, 4340 Hot Rolled Over 1 to 2, incl.  +/- 0.007"  +/- 0.008"  +/- 0.010"  ...  ...  ...  +/- 0.15625"
4140 HT, 4340 Hot Rolled  Over 1 to 2, incl.  +/- 0.007"  +/- 0.012"  +/- 0.015"  +/- 0.03125"  ...  ...  +/- 0.03125"
4140 HT, 4340 Hot Rolled  Over 2 to 4, incl.  +/- 0.008"  +/- 0.015"  +/- 0.020"  +/- 0.03125"  +/- 0.046875"  +/- 0.046875"  + 0.0625", - 0.03125"
4140 HT, 4340 Hot Rolled  Over 4 to 6, incl.  +/ 0.009"  +/- 0.015"  +/- 0.020"  +/- 0.03125"  +/- 0.046875"  +/- 0.046875"  + 0.09375", - 0.0625"
4140 HT, 4340 Hot Rolled  Over 6 to 8, incl.  +/- 0.015"  +/- 0.016"  +/- 0.025"  +/- 0.03125"  +/- 0.046875"  +/- 0.0625"  + 0.125", - 0.09375"

 

 

 

 

 

 

 

Sheet/Plate
Alloy(s)   Spec. Thick, in.  Thick Tol. (over(+)/under(-))
4130 Annealed/ Normalized Cold Rolled  0.025  +/- 0.005"
4130 Annealed/ Normalized Cold Rolled  0.032  +/- 0.005"
4130 Annealed/ Normalized Cold Rolled  0.040  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.050  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.063  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.071  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.080  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.090  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.100  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.125  +/- 0.009"
4130 Annealed/ Normalized Cold Rolled  0.160  +/- 0.009"
4130 Annealed/ Normalized Hot Rolled  0.190  +/- 0.009"

 

 

Sheet/Plate
Alloy(s)   Spec. Thick, in.  Thick Tol. (over(+)/under(-))
4340 Annealed Hot Rolled  Up to 0.5, excl.  + 0.03"/- 0.01"
4340 Annealed Hot Rolled  0.5 to 0.625, excl.  + 0.03"/- 0.01"
4340 Annealed Hot Rolled  0.625 to 0.75, excl.  + 0.03"/- 0.01"
4340 Annealed Hot Rolled  0.75 to 1, excl.  + 0.03"/- 0.01"
4340 Annealed Hot Rolled  1 to 2, excl.  + 0.06"/- 0.01"
4340 Annealed Hot Rolled  2 to 3, excl.  + 0.09"/- 0.01"
4340 Annealed Hot Rolled  3 to 4, excl.  + 0.11"/- 0.01"
4340 Annealed Hot Rolled  4 to 6, excl.  + 0.15"/- 0.01"
4340 Annealed Hot Rolled  6 to 10, excl.  + 0.24"/- 0.01"

 

 

 

 

 

 

 

Round Tubes
Alloy(s)   Spec. O.D., in. O.D. Tol. (over(+)/under(-))
4130-N Cold Drawn/ Seamless  Up to 0.499 + 0.005"/- 0.002"
4130-N Cold Drawn/ Seamless  0.500 to 1.699 + 0.007"/- 0.002"
4130-N Cold Drawn/ Seamless  1.700 to 2.099 + 0.006"/- 0.005"
4130-N Cold Drawn/ Seamless  2.100 to 2.499 + 0.008"/- 0.005"
4130-N Cold Drawn/ Seamless  2.500 to 2.899 + 0.009"/- 0.005"
4130-N Cold Drawn/ Seamless  2.900 to 3.299 + 0.011"/- 0.005"
4130-N Cold Drawn/ Seamless  3.300 to 3.699 + 0.013"/- 0.005"
4130-N Cold Drawn/ Seamless  3.700 to 4.099 + 0.013"/- 0.007"
4130-N Cold Drawn/ Seamless  4.100 to 4.499 + 0.014"/- 0.007"
4130-N Cold Drawn/ Seamless  4.500 to 4.899 + 0.016"/- 0.007"
4130-N Cold Drawn/ Seamless  4.900 to 5.299 + 0.018"/- 0.007"
4130-N Cold Drawn/ Seamless  5.300 to 5.549 + 0.020"/- 0.007"

 

 

Round Tubes
      Wall Tol. (over(+)/under(-))
Alloy(s)   Wall Thick % of OD Spec. I.D. Under 0.500" Spec. I.D 0.500" and Over
4130-N Cold Drawn / Smls.  Under 10%  +/- 10%  +/- 7.5% 
4130-N Cold Drawn / Smls.  10 to 25%  +/- 10%  +/- 6.0%
4130-N Cold Drawn / Smls.  Over 25%  +/- 12.5%  +/- 7.5%

 

 

Metric Round Tubes
Alloy(s)    Spec. O.D., mm O.D. Tol. (over(+)/under(-))
4140 Metric Cold Drawn/ TGP 8mm to 30mm +/- 0.08mm
4140 Metric Cold Drawn/ TGP 40mm +/- 0.15mm
    Spec. Wall Thickness, mm Wall Tol. (over(+)/under(-))
4140 Metric Cold Drawn/ TGP Any +/- 10% or +/- 0.1mm (which ever value is greater)

 

 

Straightness Tolerance - Seamless Round Tube
Alloy(s)   Size Max. Curvature in any 3 ft. Max. Curvature in Total Lengths
4130 & 4140 Seamless Up to 5" OD & Wall thick. over 3% of OD but not over 0.5" 0.030" 0.030 x (Number of feet/of length 3)
4130 & 4140 Seamless Over 5" to 8" incl. OD & Wall thick. over 4% of OD but not over 0.75" 0.045" 0.045 x (Number of feet/of length 3)
4130 & 4140 Seamless Over 8" to 12" incl. OD & Wall thick. over 4% of OD but not over 1" 0.060" 0.060 x (Number of feet/of length 3)
Straightness tolerance will be void once full length is cut

 

 

 

 

Balls
Grade Sphericity Dia. Tolerance per Container/Lot Diameter Tolerance Per Shipment Surface Roughness, Ra
Inches MM Inches MM Inches MM µinch µm
10 0.00001 0.0002 0.00002 0.0005 ±0.0001 ±0.00254 1 0.025
15 0.00001 0.0004 0.00003 0.0007 ±0.0001 ±0.00254 1 0.025
25 0.000025 0.0006 0.00005 0.0013 ±0.0001 ±0.00254 2 0.05
50 0.00005 0.0013 0.0001 0.0025 ±0.0002 ±0.0050 3 0.08
100 0.0001 0.0025 0.0002 0.0050 ±0.0005 ±0.0127 5 0.125
200 0.0002 0.0051 0.0004 0.0102 ±0.0010 ±0.0254 8 0.2
300 0.0003 0.0076 0.0006 0.0152 ±0.0015 ±0.0381 n/a n/a
500 0.0005 0.0127 0.001 0.025 ±0.002 ±0.050 n/a n/a
1000 0.0010 0.0254 0.002 0.051 ±0.005 ±0.127 n/a n/a
2000 n/a n/a 0.005 0.127 ±0.005 ±0.127 n/a n/a
Burnishing n/a n/a n/a n/a ±0.005 ±0.127 n/a n/a