Grain Direction Aluminum Sheet

You must pay careful attention to grain or rolling direction when bending high strength metals especially when trying to achieve a small inside bend radius.

Grain direction aluminum sheet.

The grain direction is in the rolling direction of the sheet as it was being manufactured. The software determines the smallest rectangle bounding box that aligns with the grain direction to fit the flat pattern. You can define a grain direction to use when calculating the bounding box for sheet metal parts. The grain direction is established during the metal rolling process.

Bending with the grain or parallel to the grain direction can be a contributor to material failure as bending along the grain allows for separation of the grain boundaries. As a general rule the grain line must run perpendicular to the bend to avoid the potential for cracking or fracture. Aluminum plate thickness gt 250 inch has three grain orientations each with their own strength values. From the flat pattern properties we can select a new edge for the grain direction.

A plate s grains run parallel to the rolling direction. You ll now see that your flat pattern is generated based on one edge oriented parallel to the angled edge and the other obviously perpendicular to that in drawing the rectangle. Bending metal against the grain or perpendicular to the grain is a common way to prevent material failure or cracking. Whereas bending parallel to rolling direction can lead to cracks because of destruction in grain structure.

The long tranverse lt the short transverse st and the longitudinal l. Bending with the grain gives a different result than bending against it. Once the crystallites are elongated they appear as the grain that we see in cold rolled steel. When sheetmetal is bend perpendicular to rolling direction grain rearranges.

The three orientations are. When working with aluminum plate for example you need to pay close attention to whether you are forming with longitudinal or across transverse the grain direction. By default in my testing the bounding box aligns itself with the longest straight side. From mil hdbk 5 7075 t62 2 501 3 000 thick stock ultimate tension allowable stress is l 67 ksi lt 70 ksi and st 66 ksi.

During sheet metal processing rolling operation material grains are arranged in the direction of rolling.