T (0.3580), 135 degree split point. High speed steel. 12" Aircraft Extension series
12" AIRCRAFT EXTENSION DRILL BITS (LETTER SIZES)
Specifications: 135° split-point angle prevents walking (A) . Surface treated to resist abrasion and minimize tendency of soft metals to load drill, making it ideally suited for drilling Aluminum and mild Steel . Made of High Speed Steel (HSS) . Meets NAS907 Type B and J standards