If you work in the steel industry, you understand that there are all sorts of varieties of steel used for a myriad of applications. Because of these varying applications and products, steels HARDNESS (as measured on the ROCKWELL SCALE) should fit the needs of the finished product. To find the best fit for the job, steel is generally categorized into four main grades of steel for buyers to purchase. These grades are determined by the overall hardness of the steel and manufacturers can select the grades based on which type of product and application the steel will be used for.
Commercial Steel (CS/CQ)
Typical Rb range 40-65
Commercial Steel represents the most common quality of steel that is mainly used for flat applications. Buyers looking for steel that requires little to no draw or bend would consider commercial steel a good option. Drawability is essentially the formability or structural softness of steel. If you were to think of bending or shaping steel, the harder that steel is (or the higher the Rockwell) the sturdier the steel will be. Many commercial products used in the automotive and furniture industry are manufactured from commercial grade steel.
Drawing Steel (DS) Typical Rb range 35/50
As youd imagine, drawing steel is regarded as having a higher drawability than commercial grades. Drawing steel is a softer steel that typically contains less than .05 percent carbon. If a customers product needed the ability to be moderately bent or shaped in the manufacturing process, then drawing would be a suitable choice.
Deep Drawing Steel (DDS) Typical Rb range 25/40
Deep drawing steel is reserved for fairly severe drawing applications. An example of deep drawing steel would be the softness of an aluminum can and how easily formable it is. The process of deep drawing is to radically draw into a sheet metal blank with a forming die through a fast and hard punch or hit made by a machine. This transforms the shape through material retention. The process is considered deep drawing when the depth of the part thats drawn exceeds its diameter. Deep drawing steel should be used for these deep drawing applications.
Extra Deep Drawing Steel (EDDS) Typical Rb range 15/30
For the last of the four common steel grades, there is extra deep drawing steel. This grade is for really severe drawing applications. EDDS really only allows for the product to be hit with a one or two hit draw. If it is hit more than that, then issues will be had with splitting of the steel. This is why its important for customers not to order extra deep drawing steel if they will be sending it through several different hits because it will fail.
How Hascall Steel Determines the Grades
As stated above, the determining factor in identifying steel grades is hardness. Steels hardness is measured using the Rockwell scale; and the softer steels are represented by LOWER Rockwell numbers.
Rbs are not the only determining factor of steel, chemistries, physicals, annealing cycles, etc. all play an important role in making various grades of steel. But a simple Rb test can help guide you in determining what you may need.
When Hascall Steel receives a shipment of steel from our suppliers, our own in-house laboratory accurately tests the mechanical properties to determine both the Rockwell and the tensile, yield, and elongation (TYE). This gives us trustworthy data, and allows us to confirm Rockwell results against our purchase order documents. Having an in-house lab at Hascall Steel is an advantage to us in our pursuit of knowing our material, and accurately matching our inventory to our customers grade requirements.
Sheet metal thickness is an important factor in fabrication. Metal fabrication shops often work with raw stock sheet metal from 0.02 to 0.250 thick. What does that mean for you, the customer?
Sheet thickness affects the tools and time needed to manipulate the metal and fabricate your design. Since sheet metal thickness can change how we work with the material, it influences the cost of your project.
Sheet metal gauges specify thickness. Find out more about gauges. Use this resource to explore sheet metal gauges for steel and aluminum.
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What Do Sheet Metal Gauges Mean?
Sheet metal gauges are a form of measurement. They are not to be confused with sheet metal grades. Grades refer to a metals composition. Gauges refer to a sheets thickness.
While we can measure sheet metal in inches, millimeters and mils, we can also find a metals thickness in relation to its weight per square foot. Metal gauges are identifiers for the relationship between thickness and weight.
In other contexts, larger numbers mean that theres more of something. As numbers increase, the subject gets larger, longer or heavier. Imagine you are measuring office tables. You know a 6 table is longer than a 3 table. The larger measurement indicates a larger object.
The opposite occurs with gauges. Gauge numbers get larger as the sheet metal thins. Higher sheet metal gauges indicate that youre working with a thinner sheet. Lower gauge numbers identify thicker sheets of metal. As gauges increase, metal sheets get thinner.
Not all types of metals use the same gauge system. Aluminum and other nonferrous metals use the Brown and Sharpe system (also known as the American Wire Gauge). Carbon steel, galvanized steel and stainless steel use the Manufacturers Standard Gauge scale.
Below are sheet metal gauge charts for common metals. Youll find the gauge and its corresponding thickness in inches and millimeters.
Carbon Steel Gauge Thickness Chart
Carbon Steel Sheets
Gauge Inches MM
3
0.
6.07
4
0.
5.69
5
0.
5.31
6
0.
(4.94)
7
0.
4.55
8
0.
4.18
9
0.
3.80
10
0.
3.42
11
0.
3.04
12
0.
2.66
13
0.
2.28
14
0.
1.90
15
0.
1.71
16
0.
1.52
17
0.
1.37
18
0.
1.21
19
0.
1.06
20
0.
0.91
21
0.
0.84
22
0.
0.76
23
0.
0.68
24
0.
0.61
25
0.
0.53
26
0.
0.45
27
0.
0.42
28
0.
0.38
29
0.
0.34
30
0.
0.30
These steel gauge charts arent exhaustive lists. A 38-gauge steel sheet, for example, is 0. thick.
Stainless Steel Gauges
Stainless Steel SheetsGauge Inches MM
7
0.
4.76
8
0.
4.37
9
0.
3.97
10
0.
3.57
11
0.
3.18
12
0.
2.78
13
0.094
2.4
14
0.
1.98
15
0.07
1.8
16
0.
1.59
17
0.056
1.4
18
0.
1.27
19
0.044
1.1
20
0.
0.95
21
0.034
0.86
22
0.
0.79
23
0.028
0.64
24
0.025
0.64
25
0.022
0.56
26
0.019
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0.48
27
0.017
0.43
28
0.016
0.41
29
0.014
0.36
30
0.013
0.33
Galvanized Steel Thicknesses
Galvanized Steel SheetsGauge Inches MM
8
0.
4.27
9
0.
3.89
10
0.
3.51
11
0.
3.13
12
0.
2.75
13
0.
2.37
14
0.
1.99
15
0.
1.8
16
0.
1.61
17
0.
1.46
18
0.
1.31
19
0.
1.16
20
0.
1.01
21
0.
0.93
22
0.
0.85
23
0.
0.78
24
0.
0.70
25
0.
0.63
26
0.
0.55
27
0.
0.51
28
0.
0.47
29
0.
0.44
30
0.
0.40
Aluminum Sheet Gauge Chart
Aluminum, copper and other nonferrous metals use the Brown and Sharpe system. Below are the thicknesses associated with aluminum sheet metal gauges.
Aluminum SheetsGauge Inches MM
6
0.162
4.1
7
0.
3.67
8
0.
3.26
9
0.
2.91
10
0.
2.59
11
0.
2.3
12
0.
2.05
13
0.072
1.8
14
0.
1.63
15
0.057
1.4
16
0.
1.29
17
0.045
1.1
18
0.
1.02
19
0.036
0.91
20
0.
0.81
21
0.028
0.71
22
0.025
0.64
23
0.023
0.58
24
0.02
0.51
25
0.018
0.46
26
0.017
0.43
27
0.014
0.36
28
0.
0.32
29
0.
0.29
30
0.
0.25
Where Did Sheet Metal Gauges Come From?
Sheet metal gauges originate from wire drawing. Before the industrial revolution, wire was sold by weight. Selling by weight alone was problematic. Wires could be many thicknesses at the same weight, which meant customers ended up with nonuniform wire.
At the time, there was no method for measuring wire diameter, so it was challenging to communicate what wire size was needed. Wire drawers sought a solution by quoting wire based on the number of draws required to create it. The number of draws became the gauge.
As a form of measurement, gauges developed from drawing wires through thinner and thinner dies and assigning each a number. When steelmakers began rolling sheets of steel, they followed suit.
Steelmakers discovered it was difficult to measure sheets by their thickness. Instead, they wanted to measure sheets by weight per square foot. Steel producers began using the gauge system to specify sheet metal thickness.
Why Do Sheet Metal Gauges Matter?
A sheet metals gauge can affect the methods used to cut, form and weld it.
Gauges help engineers determine the most effective design and the path forward for manufacturing it. Fabricators, welders and machine operators also benefit from this knowledge since sheet metal gauges help determine the best methods to use.
For example, high heat can harm thin-gauge metals. Burn-through and surface distortion are risks when welding thinner materials, so welders must try to minimize the metals heat exposure. With thinner materials, welders may start and stop often to let the weld area cool or spread smaller welds out over the joint.
Thin-gauge sheets can be challenging to weld, whereas thicker materials are more difficult to bend. By maintaining a minimum inside bend radius, you can minimize cracking and hardening at the bend when working with thick sheets or plates. The minimum radius increases as a sheets thickness increases.
These are two examples of how sheet metal gauges play into the fabrication process. Do you have questions about sheet metal? Do you need an experienced fabrication company to develop custom metal components?
Metaltech has helped companies produce custom parts for over 20 years. We offer a full range of metal manufacturing capabilities. Well answer your questions and guide you through the manufacturing process. Trust our team to do it rightevery time.
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