Accounting for scrap materials
How you account for scrap depends on how you have logged your initial manufactures. If in your manufacture you have included both the used material and the scrap as part of the total material usage, then this will already be accounted for in your inventory and you will not need to make any adjustments.
If you have not included your scrap in your manufacture usage, you'll want to create an adjustment to remove the total scrap amount from your stock on hand - the easiest way to do this is via regular stocktakes as this will apply the difference automatically for you.
How do I add a Material Inventory Adjustment?
What is a stocktake?