Case Study #6

Part name: Mil-spec Knurled aluminum nut

Material: 2024 aluminum

Challenge: The blueprint specs on this relatively complicated military replacement part were incomplete because of the age of the part, nearing obsolescence, so we had to reverse-engineer many of the internal features from a sample. This, coupled with the large amount of material to be removed and the need to engrave a part number on a conical surface, made this part challenging, in a small quantity.

Solution: With our substantial inventory of measuring devices, we were able to render a complete drawing of the piece in our CAD-CAM program. We used a machinable 3-jaw chuck to evenly distribute chucking pressure, and fine-tuned this pressure to allow for centrifugal forces that push the jaws apart and reduce this pressure at high RPM. The piece was machined on the Hyundai lathe, and the part number was embossed into the conical surface using a press and a special curved metal type holder that we designed and fabricated.