What is the difference between a sales order Bom and the Manufacturing BOM?
Is ithe sales order Bom just the Manufacturing BOM times the number of pcs in the order?
e.g. an order for 4 chairs SO BOM = 4 x ( mBOM of: 4 legs; 1 back; 1 seat)
thanks.

yes, it will replace 4 chair with their BOM Components.

sales order BOM gets copied from production BOM. It is not maintained by a user, but gets created when a sales order is created for phantom item. It is not sales order qty multiplied by BOM qty, but it is same as producution order BOM. The net requirement is reflected in tdinv150 table.