1. Standard and actual thicknesses of stainless steel are different.
The standard thickness of stainless steel refers to the thickness value marked on it (such as 1mm, 2mm, 3mm, 4mm, etc.).
The actual thickness of stainless steel refers to its measured thickness (which is generally accurate to two decimal places, such as 0.85mm, 1.91mm, 2.75mm, 3.80mm, etc.).
2. What is the difference between standard and actual thicknesses of stainless steel plates?
The difference between standard and actual thicknesses of stainless steel plates depends on the standards for stainless steel materials.
The standard thickness of stainless steel plates can be based on the pressure bearing standard GB/T24511-2017, the hot-rolled national standard GB/T4237-2015, the cold-rolled national standard GBT3280-2015 or the American hot-rolled standard. cold standard ASTM A240/A240M-15a, among others.
The first three standards are the national standards for thickness tolerance of stainless steel plates.
To understand the difference in thickness according to the national standard, please refer to the standard and actual thickness comparison table of stainless steel plates below.
Table ① and Table ②:
When the width of the steel plate is 1.2m, the comparison between the standard thickness and the actual thickness of the stainless steel plate is as follows:
Comparison Table of Standard Thickness and Actual Thickness of Stainless Steel Plate ①
| Standard thickness | Actual thickness (when the width of the steel plate is 1.2m) (unit: mm) |
||||
| In general | Comply with pressure bearing standard GB/T24511-2017 |
Conforms to the national hot rolling standard GB/T4237-2015 |
Conforms to the national cold rolling standard GB/T3280-2015 |
Conforms to the American standard for cold rolling ASTM A240/A240M-15a |
|
| 0.5 | 0.3~0.5 | – | – | 0.45~0.55 | 0.46~0.54 |
| 0.8 | 0.6~0.8 | – | – | 0.71~0.89 | 0.75~0.85 |
| 1 | 0.8~1 | – | – | 0.9~1.1 | 0.94~1.06 |
| 1.2 | 1~1.2 | – | – | 0.9~1.1 | 1.12~1.28 |
| 1.5 | 1.2~1.5 | – | – | 1.38~1.62 | 1.42~1.58 |
| two | 1.6~2 | – | 1.78~2.22 | 1.83~2.17 | 19~2.1 |
| 2.5 | 2.2~2.5 | – | 1.78~2.22 | 2.28~2.72 | 2.4~2.6 |
| 3 | 2.6~3 | 2.75~3.25 | 2.75~3.25 | 2.78~3.22 | 2.87~3.13 |
Comparison Table of Standard Thickness and Actual Thickness of Stainless Steel Plate ②
| Standard thickness | Actual thickness (when the width of the steel plate is 1.2m) (unit: mm) |
||||
| In general | Comply with pressure bearing standard GB/T24511-2017 |
Conforms to the national hot rolling standard GB/T4237-2015 |
Conforms to the national cold rolling standard GB/T3280-2015 |
Conforms to the American standard for cold rolling ASTM A240/A240M-15a |
|
| 4 | 3.5~4 | 3.72~4.28 | 3.72~4.28 | 3.75~4.25 | 3.83~4.17 |
| 5 | 4.5~5 | 4.7~5.31 | 4.69~5.31 | 4.65~5.35 | 4.83~5.17 |
| 6 | 5.5~6 | 5.7~6.33 | 5.67~6.33 | 5.6~6.4 | 5.8~6.2 |
| 8 | 7.5~8 | 7.7~8.38 | 7.62~8.38 | 7.5~8.5 | 7.77~8.23 |
| 10 | 9.5~10 | 9,710.42 | 9.58~10.42 | – | – |
| 12 | 11.5~12 | 11.7~12.45 | 11:55am~12:45pm | – | – |
| 14 | 13.5~14 | 13.7~14.45 | 1:55pm~2:45pm | – | – |
| 16 | 15.5~16 | 15.7~16.5 | 15.55~16.45 | – | – |
Table ③ and Table ④:
When the width of the steel plate is 1.5m, the standard thickness and the actual thickness of the stainless steel plate are compared as follows:
Comparison Table of Standard Thickness and Actual Thickness of Stainless Steel Plate ③
| Standard thickness | Actual thickness (when the width of the steel plate is 1.5m) (unit: mm) |
||||
| In general | Comply with pressure bearing standard GB/T24511-2017 |
Conforms to the national hot rolling standard GB/T4237-2015 |
Conforms to the national cold rolling standard GB/T3280-2015 |
Conforms to American standard STMA240/A240M-15a cold rolling mill |
|
| 0.5 | 0.3~0.5 | – | – | 0.42~0.58 | – |
| 0.8 | 0.6~0.8 | – | – | 0.7~0.9 | – |
| 1 | 0.8~1 | – | – | 0.88~1.12 | 0.92~1.08 |
| 1.2 | 1~1.2 | – | – | 1.08~1.32 | 1.12~1.28 |
| 1.5 | 1.2~1.5 | – | – | 1.35~1.65 | 1.4~1.6 |
| two | 1.6~2 | – | – | 1.8~2.2 | 1.89~2.11 |
| 2.5 | 2.2~2.5 | – | – | 2.25~2.75 | 2.37~2.63 |
| 3 | 2.6~3 | 2.72~3.28 | 2.72~3.28 | 2.75~3.25 | 2.85~3.15 |
Comparison Table of Standard Thickness and Actual Thickness of Stainless Steel Plate ④
| Standard thickness | Actual thickness (when the width of the steel plate is 1.5m) (unit: mm) |
||||
| In general | Comply with thrust bearing standard GB/T24511-2017 | Conforms to national hot rolling standard GB/T4237-2015 | Conforms to the national cold rolling standard GB/T3280-2015 | Conforms to American cold rolling standard ASTM A240/A240M-15a | |
| 4 | 3.5~4 | 3.7~4.31 | 3.69~4.31 | 3.6~4.4 | 3.83~4.17 |
| 5 | 4.5~5 | 4.7~5.33 | 4.67~5.33 | 4.55~5.45 | 4.81~5.19 |
| 6 | 5.5~6 | 5.7~6.36 | 5.64~6.36 | 5,556.45 | 5.77~6.23 |
| 8 | 7.5~8 | 7.7~8.39 | 7.61~8.39 | 7.5~8.5 | 7.75~8.25 |
| 10 | 9.5~10 | 9.7~10.43 | 9.57~10.43 | – | – |
| 12 | 11.5~12 | 11.7~12.47 | 11.53~12.47 | – | – |
| 14 | 13.5~14 | 13.7~14.47 | 13.53~14.47 | – | – |
| 16 | 15.5~16 | 15.7~16.53 | 15.53~16.47 | – | – |
The standard for the actual thickness of 304 stainless steel is the same as the previous example.
The actual thickness of 304 stainless steel can be determined based on the relevant width and pattern of the stainless steel plate.
3. Impact of Standard and Actual Stainless Steel Thickness
It is important to note that the actual thickness of stainless steel is generally less than the standard thickness.
Standard thickness is also known as theoretical thickness.
For example, a stainless steel plate with an actual thickness of 2.75mm or 2.8mm will be considered a 3mm plate (i.e. 3mm thick).
When purchasing stainless steel sheets, it is essential to be aware of the difference between the actual and standard thickness.
If the cost of stainless steel material is calculated based on its weight, the price per unit weight is mainly impacted by market conditions and material quality.
If the total price of stainless steel material is calculated based on theoretical weight (weight calculated using standard thickness; see calculation formula for steel sheet weight), the price per unit weight is influenced by a combination of factors, including the difference between standard weight thickness and actual thickness, market conditions and material quality.
