Inquiry (采购产品): Black Oxide Appearance Between Classes Hello, my name is Ming and I am a mechanical design engineer at Rockwell Collins, Inc. For one of our designs that we adopted through a merger, I noticed that on many detailed drawings that call out steel 1018, 1040, grade 30, a black oxide coating, class 3 is called out. According to MIL-C-13924, Class 1 should be used for these types of steels (low alloy carbon). Can you think of any reason why the previous designers would have chosen Class 3 even though it should be Class 1 for these types of steel? One possibility could be the appearance. Does a Class 3 produce a more uniform, repeatable appearance compared to a Class 1 black oxide treatment? **** Hidden Message ***** Ming Huang 14192 Franklin Ave. Tustin, CA 92780 USA Company: Rockwell Collins, Inc. Title: Mechanical Engineer Phone: 714-929-3343 E-mail: mhuang@rockwellcollins.com **** Hidden Message ***** mhuang@rockwellcollins.com
