Fabrication at its Best

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SHEET METAL - An Insight

Standard sheet metal gauges[8][9]
GaugeU.S. standard[10][11]
for sheet and plate
iron and steel
decimal inch (mm)		Steel[12]
inch (mm)		Galvanized steel
inch (mm)		Stainless steel
inch (mm)		Aluminium
inch (mm)		Zinc[12]
inch (mm)
00000000.5000 (12.70)..............................
0000000.4688 (11.91)..............................
000000.4375 (11.11)..............................
00000.4063 (10.32)..............................
0000.3750 (9.53)..............................
000.3438 (8.73)..............................
00.3125 (7.94)..............................
10.2813 (7.15)..............................
20.2656 (6.75)..............................
30.2500 (6.35)0.2391 (6.07)..................0.006 (0.15)
40.2344 (5.95)0.2242 (5.69)..................0.008 (0.20)
50.2188 (5.56)0.2092 (5.31)..................0.010 (0.25)
60.2031 (5.16)0.1943 (4.94)............0.162 (4.1)0.012 (0.30)
70.1875 (4.76)0.1793 (4.55)......0.1875 (4.76)0.1443 (3.67)0.014 (0.36)
80.1719 (4.37)0.1644 (4.18)0.1681 (4.27)0.1719 (4.37)0.1285 (3.26)0.016 (0.41)
90.1563 (3.97)0.1495 (3.80)0.1532 (3.89)0.1563 (3.97)0.1144 (2.91)0.018 (0.46)
100.1406 (3.57)0.1345 (3.42)0.1382 (3.51)0.1406 (3.57)0.1019 (2.59)0.020 (0.51)
110.1250 (3.18)0.1196 (3.04)0.1233 (3.13)0.1250 (3.18)0.0907 (2.30)0.024 (0.61)
120.1094 (2.78)0.1046 (2.66)0.1084 (2.75)0.1094 (2.78)0.0808 (2.05)0.028 (0.71)
130.0938 (2.38)0.0897 (2.28)0.0934 (2.37)0.094 (2.4)0.072 (1.8)0.032 (0.81)
140.0781 (1.98)0.0747 (1.90)0.0785 (1.99)0.0781 (1.98)0.0641 (1.63)0.036 (0.91)
150.0703 (1.79)0.0673 (1.71)0.0710 (1.80)0.07 (1.8)0.057 (1.4)0.040 (1.0)
160.0625 (1.59)0.0598 (1.52)0.0635 (1.61)0.0625 (1.59)0.0508 (1.29)0.045 (1.1)
170.0563 (1.43)0.0538 (1.37)0.0575 (1.46)0.056 (1.4)0.045 (1.1)0.050 (1.3)
180.0500 (1.27)0.0478 (1.21)0.0516 (1.31)0.0500 (1.27)0.0403 (1.02)0.055 (1.4)
190.0438 (1.11)0.0418 (1.06)0.0456 (1.16)0.044 (1.1)0.036 (0.91)0.060 (1.5)
200.0375 (0.95)0.0359 (0.91)0.0396 (1.01)0.0375 (0.95)0.0320 (0.81)0.070 (1.8)
210.0344 (0.87)0.0329 (0.84)0.0366 (0.93)0.034 (0.86)0.028 (0.71)0.080 (2.0)
220.0313 (0.80)0.0299 (0.76)0.0336 (0.85)0.031 (0.79)0.025 (0.64)0.090 (2.3)
230.0281 (0.71)0.0269 (0.68)0.0306 (0.78)0.028 (0.71)0.023 (0.58)0.100 (2.5)
240.0250 (0.64)0.0239 (0.61)0.0276 (0.70)0.025 (0.64)0.02 (0.51)0.125 (3.2)
250.0219 (0.56)0.0209 (0.53)0.0247 (0.63)0.022 (0.56)0.018 (0.46)......
260.0188 (0.48)0.0179 (0.45)0.0217 (0.55)0.019 (0.48)0.017 (0.43)......
270.0172 (0.44)0.0164 (0.42)0.0202 (0.51)0.017 (0.43)0.014 (0.36)......
280.0156 (0.40)0.0149 (0.38)0.0187 (0.47)0.016 (0.41)0.0126 (0.32)......
290.0141 (0.36)0.0135 (0.34)0.0172 (0.44)0.014 (0.36)0.0113 (0.29)......
300.0125 (0.32)0.0120 (0.30)0.0157 (0.40)0.013 (0.33)0.0100 (0.25)......
310.0109 (0.28)0.0105 (0.27)0.0142 (0.36)0.011 (0.28)0.0089 (0.23)......
320.0102 (0.26)0.0097 (0.25)........................
330.0094 (0.24)0.0090 (0.23)........................
340.0086 (0.22)0.0082 (0.21)........................
350.0078 (0.20)0.0075 (0.19)........................
360.0070 (0.18)0.0067 (0.17)........................
370.0066 (0.17)0.0064 (0.16)........................
380.0063 (0.16)0.0060 (0.15)........................

Tolerances

During the rolling process the rollers bow slightly, which results in the sheets being thinner on the edges.[3] The tolerances in the table and attachments reflect current manufacturing practices and commercial standards and are not representative of the Manufacturer's Standard Gauge, which has no inherent tolerances.
Steel sheet metal
tolerances[13][3]
GaugeNominal
[in (mm)]		Max
[in (mm)]		Min
[in (mm)]
100.1345 (3.42)0.1405 (3.57)0.1285 (3.26)
110.1196 (3.04)0.1256 (3.19)0.1136 (2.89)
120.1046 (2.66)0.1106 (2.81)0.0986 (2.50)
140.0747 (1.90)0.0797 (2.02)0.0697 (1.77)
160.0598 (1.52)0.0648 (1.65)0.0548 (1.39)
180.0478 (1.21)0.0518 (1.32)0.0438 (1.11)
200.0359 (0.91)0.0389 (0.99)0.0329 (0.84)
220.0299 (0.76)0.0329 (0.84)0.0269 (0.68)
240.0239 (0.61)0.0269 (0.68)0.0209 (0.53)
260.0179 (0.45)0.0199 (0.51)0.0159 (0.40)
280.0149 (0.38)0.0169 (0.43)0.0129 (0.33)
Aluminium sheet metal tolerances[3]
Thickness
[in (mm)]		Sheet width
36 (914.4)
[in (mm)]		48 (1,219)
[in (mm)]
0.018–0.028  (0.46–0.71)0.002 (0.051)0.0025 (0.064)
0.029–0.036  (0.74–0.91)0.002 (0.051)0.0025 (0.064)
0.037–0.045  (0.94–1.1)0.0025 (0.064)0.003 (0.076)
0.046–0.068  (1.2–1.7)0.003 (0.076)0.004 (0.10)
0.069–0.076  (1.8–1.9)0.003 (0.076)0.004 (0.10)
0.077–0.096  (2.0–2.4)0.0035 (0.089)0.004 (0.10)
0.097–0.108  (2.5–2.7)0.004 (0.10)0.005 (0.13)
0.109–0.125  (2.8–3.2)0.0045 (0.11)0.005 (0.13)
0.126–0.140  (3.2–3.6)0.0045 (0.11)0.005 (0.13)
0.141–0.172  (3.6–4.4)0.006 (0.15)0.008 (0.20)
0.173–0.203  (4.4–5.2)0.007 (0.18)0.010 (0.25)
0.204–0.249  (5.2–6.3)0.009 (0.23)0.011 (0.28)
Stainless steel sheet metal tolerances[3]
Thickness
[in (mm)]		Sheet width
36 (914.4)
[in (mm)]		48 (1,219)
[in (mm)]
0.017–0.030  (0.43–0.76)0.0015 (0.038)0.002 (0.051)
0.031–0.041  (0.79–1.0)0.002 (0.051)0.003 (0.076)
0.042–0.059  (1.1–1.5)0.003 (0.076)0.004 (0.10)
0.060–0.073  (1.5–1.9)0.003 (0.076)0.0045 (0.11)
0.074–0.084  (1.9–2.1)0.004 (0.10)0.0055 (0.14)
0.085–0.099  (2.2–2.5)0.004 (0.10)0.006 (0.15)
0.100–0.115  (2.5–2.9)0.005 (0.13)0.007 (0.18)
0.116–0.131  (2.9–3.3)0.005 (0.13)0.0075 (0.19)
0.132–0.146  (3.4–3.7)0.006 (0.15)0.009 (0.23)
0.147–0.187  (3.7–4.7)0.007 (0.18)0.0105 (0.27)

Bending

The equation for estimating the maximum bending force is,
F_{max} = k \frac{TLt^{2}}{W},
where k is a factor taking into account several parameters including friction. T is the ultimate tensile strength of the metal. L and t are the length and thickness of the sheet metal, respectively. The variable W is the open width of a V-die or wiping die.


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A table of comparison among presses[edit]

Comparison of various machine presses
Type of pressType of framePosition of frameActionMethod of actuationType of driveSuspensionRamBed
Open-backGapStraight-sideArchPillerSolidTie rodVerticalHorizontalInclinableInclinedSingleDoubleTripleCrankFront-to-back crankEccentricToggleScrewCamRack & pinionPistonOver directGeared, overdriveUnder directGeared, underdriveOne-pointTwo-pointFour-pointSingleMultipleSolidOpenAdjustable
BenchXXXXXXXXXXXXXXXXX
Open-back inclinableXXXXXXXXXXXXXXXXXX
Gap-frameXXXXXXXXXXXXXXXXXXXXXXXX
Adjustable-bed hornXXXXXXXXXXXXXXX
End-wheelXXXXXXXXXXXX
Arch-frameXXXXXXXXXXXX
Straight-sideXXXXXXXXXXXXXXXXXXXXXXXXXX
ReducingXXXXXXXXXXXXXXX
Knuckle-lever
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Toggle-draw
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Cam-drawing
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Two-point single-action
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
High-production
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Dyeing machine
X
X
X
X
X
X
X
X
X
X
Transfer
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Flat-edge trimming
X
X
X
X
X
X
X
X
Hydraulic
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Press brake
X
X
X
X
X
X
X
X
X
X
X
X


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