Autodesk Advance Steel – Captive Nuts

12 January 2021advance steel



Certain industries and structure types seem to use a lot of Captive Nuts in their structures. Whether these are inside RHS or on the back of thin sheet metal or in other hard to reach areas they all need to be welded to the parent object. Advance Steel does not have a standard tool for this, and you cannot weld the nuts that are placed with normal bolts in the system. So how should you create these in your Advance Steel models.

Advance Steel Captive Nuts

The main idea is that you must place the bolts without nuts and then place the captive nuts as special parts.

Regardless of whether you place the bolts as part of a joint or independently, select a type and assembly without a nut and washer. For example, you can select “Set Screw” or “EN ISO 4014 – Setless”.

Then for the nut you need to insert a special part. You can use the centre of the bolt hole as a reference point. The symbols folder already contains M10 to M24 nuts and washers so simply select one of those. You need your UCS Z parallel to the axis of the bolt.

You can watch a full webinar on using special parts (including captive nuts) by following this link to our Advance Steel Content Portal. It is called “Advance Steel Working With Special Parts”.

Advance Steel Symbols

I highly recommend that you set the “Commodity Number” property of your special part to something easy to recognise. Remember, this is what appears on any Bill of Materials and labels in drawings.

Advance Steel Special Part

Once you have placed your first nut you can use a pattern to copy it to the other bolts in the group. One single Point Weld is sufficient to weld all the nuts in a group to the beam or plate.

These nuts will now appear on shop drawings for your assembly.

Advance Steel Shop Drawing

Normally Special Parts will NOT show on any BOM for Bolts and Anchors but will show on other BOMs such as “UK Material List”.

If this is confusing, contact me or my colleagues at Graitec UK. With some customisation we can make it so the captive nuts appear on the bolt lists and not other lists. Of course, customisation is not part of a support contract so this would have to be part of some kind of service project for you. We can do many things to help you work more efficiently than the out of the box system.

If you want to find out more about this or Advance Steel software, just click on the button below to request more information.

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