Drills Meet Key Aerospace Standard
IMTS 2018: Dormer Pramet’s Precision Twist Drill series of drilling tools are manufactured according to National Aerospace Standards (NAS).
Dormer Pramet’s Precision Twist Drill series of drilling tools are manufactured according to National Aerospace Standards (NAS). Standard drills are available in stub, jobber and aircraft extension lengths and are made from HSS (bright or steam oxide) and HSCo (bronze oxide) substrates. Fractional, wire gauge, letter and metric size ranges are available. The R10A, R10B, R10CO, R88CO, 500-12 and CO500-12 sets are designed to meet the NAS 907 standard.
Threaded hex shank drills made from HSS substrates are available in stub, short and long lengths. All are manufactured with ¼-28 UNF threads and 5/16" wrenching flats. Diameters are available in fractional, wire gauge and letter ranging from 0.0980" to 0.2500". HSCo and solid carbide substrate options are available for the drilling portion of the tool. The TS41, TS10 and TS52 sets were designed to meet the NAS 965 standard.
Running rotary milling cutters at the proper speeds and feeds is critical to obtaining long tool life and superior results, and a good place to start is with the manufacturer's recommendations. These formulas and tips provide useful guidelines.
The more common twist drill point geometries often are not the best for the job at hand. By choosing the best point for the material being drilled, it is possible to achieve better tool life, hole geometry, precision, and productivity.
One of the most common methods of tapping in use today on CNC machines is 'rigid tapping' or 'synchronous feed tapping.' A rigid tapping cycle synchronizes the machine spindle rotation and feed to match a specific thread pitch. Since the feed into the hole is synchronized, in theory a solid holder without any tension-compression can be used.