Cost Report Questions Involving Machining

[coleasterling]

I have been going through the cost report procedures for machining and am confused by the requirements for machining operations.

1. Appendix C1 says, "All processes require a minimum of 1mm (0.040 inches) of machining stock to be removed from each surface of the part with machining."

Let's say I am cutting a simple part out on the CNC. I've ordered stock that is the SAME thickness as my finish part and it will be jigged so that I can just cut out the perimeter of the part at full depth. In other words, there is no need to take 0.040" off in a facing operation because the stock is flat/nice enough already for that part's intended purpose.

Do I have to count an extra 0.080" of material added to the top and bottom faces of my stock for purposes of the cost report? That's absurd if so.


2. Appendix C1 does not go into the situation where you use drops from previous machining operations as the stock for another part. For example, I have a 12" x 12" x 1" plate and cut a part out of the middle of it. I end up with a drop that is approximately 3" x 3" x 0.75". In the cost report, I count the full 12" by 12" plate towards the first part's stock removed, so do I need to count the 2nd part's stock removed? Or, not count the 3" x 3" piece in the material removed for the 12" x 12" piece and then count it for the 3" x 3" piece?

[Alex Lewis]

1. My interpretation is that any machined surface must have a minimum of 1mm removed, therefore you wouldn't need to include extra cost to face the top and bottom

2. Just put a note in the second part that the material was costed in the first part and provide a diagram that proves it work.