Sheet Metal Flatness Tolerance Standard

Standard astm mill toleranes flatness hot dipped metallic oated sheet cut lengths over 12 in width specified to tenion leveled standard of flatness astm 924 97a specified minimum thickness inch over 019 thru 032 incl.

Sheet metal flatness tolerance standard.

During the rolling process the rollers bow slightly which results in the sheets being thinner on the edges. 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. 4 for widths over 6 ft these tolerances alloy for any 6 ft of total width. 1 1 this specification covers the general requirements for steel sheet in coils and cut lengths.

Sheet metal guage tolerances. Linear tolerances should be held as loose as possible. 5 short span flatness is the deviation from flat over full span for spans 2 ft and less 2 tx51 is a general designation for the following stress relieved tempers. For sheet metal parts iso 2768 mk is used.

Practical tolerances vary according to the design requirements. T351 t451 t651 t851 t7351 and t7651. Specifications a414 a414m a424 a424m a606 a606m a659 a659m a794 a794m a1008 a1008m a1011 a1011m and a1039. And for machined components iso 2768 fh can be used.

Flatness and edge waviness tolerances. Tolerances of 010 should be considered minimum. Tight tolerances raise the cost of manufacturing significantly. Specifications a 480 and ams 2242 cover many of the stainless steel flat products.

There is a larger tolerance range above 3000mm lengths. It applies to the following specifications that describe carbon steel structural steel and high strength low alloy steel hsla furnished as hot rolled sheet and cold rolled sheet. In contrast to the standards replaced bs en 10259 introduces tolerances for flatness of sheet plate and cut lengths with both a normal and special range. The resulting bend angle variation and sometimes the required adjustment to the flat layout contributes to the reason that machined parts typical tolerance of 0 002 in can routinely have tighter tolerances than precision sheet metal parts typical tolerance of 0 010 in.

The tolerance for all thicknesses and all sizes is 1 16 inch 0625 per 6 inches of width or fraction thereof. Flatness tolerances for sheet are published only for full size sheets. Tolerance class is defined as per design requirements and manufacturing capability. Sheet metal tolerances should not be tighter than necessary to make the part functional.

It is important to remember that these tolerances apply to the mill produced product where they have specialized equipment to perform flattening operations.