Change the assembly main part

The main part in a steel assembly has other parts welded or bolted to it. By default, the main part is not welded or bolted to any other parts. You can change the main part in an assembly.

If needed, check what is currently the main part of the assembly.

Use the Inquire tool to check which objects belong to a particular assembly.
Ensure that the Select objects in assemblies selection switch is active.
On the Steel tab, click Assembly > Set as main object.
Select the new main part.

Tekla Structures changes the main part.

Change the main assembly in a nested assembly

When you join two or more assemblies together, the assembly with the largest volume becomes the main assembly. You can change the main assembly in a nested assembly at any time.

Select the new main assembly.
Right-click and select Assembly > Set as New Main Sub-Assembly.

Remove objects from an assembly

Select the part or sub-assembly you want to remove.
Right-click and select Assembly > Remove from Assembly.

Check and highlight objects in an assembly

Use the Inquire tool to check which objects belong to a particular assembly.

On the ribbon, click the down arrow next to , and then select Assembly objects.

Select a part that belongs to an assembly.

Tekla Structures highlights the other parts that belong to the same assembly. The following colors are used:


Object type	Highlight color
Concrete - main part	magenta
Concrete - secondary part	cyan
Reinforcement	blue
Steel part - main part	orange
Steel part - secondary part	yellow

Explode an assembly

When you explode a nested assembly, Tekla Structures breaks the assembly hierarchy level by level, always starting from the highest level. You need to use the Explode command several times to break a nested assembly back to single parts.

You can also explode sub-assemblies to single parts without breaking the entire assembly hierarchy.

Select the assembly or sub-assembly you want to explode.
Do one of the following:
- To explode the entire assembly, right-click and select Assembly > Explode.
- To only explode the sub-assembly, right-click and select Assembly > Explode Sub-Assembly.

Assembly examples

Column corbel

A column corbel is fabricated in one workshop, and then attached to the column in another workshop. Model the corbel as a sub-assembly of the column. Then create an assembly drawing for each workshop: one assembly drawing showing how the corbel is welded together, another assembly drawing showing how the corbel and the other part are welded to the column.

(1) Drawing 2, Workshop 2

(2) Drawing 1, Workshop 1

Complex truss

Model the halves of a complex truss as assemblies. Create assembly drawings for the workshop to fabricate the truss halves. Then create another assembly drawing showing how the halves should be joined on site.

Built-up profile

In a frame of built-up columns and beams, each built-up profile can be a sub-assembly. You can create an assembly drawing showing the entire frame, and separate drawings showing how the columns and beams are constructed.

Modify assemblies