First, what machine and control are you using? Only a very late-model control with fast processing time would be able to thread at those spindle speeds reliably. On most Fanuc 18i-TB, 16i-TB and 21T controls, speeds of about 2000 are where you should max out, though some Star and Maier machines with 1320ipm (33m/min) rapid rates can go as high as 2500 in G76 cycles without too much trouble as long as your approach and retract amounts aren't excessive.
DO use a full-form 32p threading insert WITH the proper angled anvil under it for that small diameter. I recommend Valenite threading tools for this application. Depending upon what shank size your lathe takes, I can recommend the right holder, but for the threading insert and anvil you will want:
Insert 16ER32UN, Grade VC929 EDP No. 01942
Anvil CAE 16 3.5P EDP No. 08264
In that G76 cycle, use a different value for the first "P" parameter, to match the thread included angle and give the tool a compound angle infeed. It should read "P010060", or better yet (to give it a clean-up chip on the backside flank and plently of "free spring passes") use: "P040059"
hth  |