Finding youngest cricketers is a prerogative of Pakistan cricket, let the world say what they may..
Youngest test centurions, youngest ODI centurions or youngest cricketers as a whole are the lists filled with Pakistani cricketers and today at Melbourne, Mohammad Aamer became the youngest bowler to take a 5 wicket haul in and against Australia. Overall, Mohammad Aamer is second in terms of age for bowlers who took 5 wicket haul in a test match innings, behind another Pakistani = Nasim-ul-Ghani.
Nasim was one of starting Pakistani bowling stars when they first entered test cricket and on 13 March at Georgetown, this left arm swing (and orthodox spin) bowler was less than unplayable but enough to register the elite record which still hasn't been broken. At the age of 16 years and 303 days, on his first tour outside his country, Nasim dismissed Windies batting stalwarts like Gary Sobers, Everton weeks, Collie Smith, Rohan Kanhai and then Ivan Madray and number 10 Roy Gilchrist. West Indies still got upto 410, took 2 run lead and ended up winning that 1958 test match by 8 wickets, chasing 317 (Nasim didn't get no more wicket from 28 overs he bowled in second innings).
Nasim played 29 tests for Pakistan and took 62 wickets.
Who are the other youngest bowlers to take 5 wicket haul. If you look at following list carefully, you'll find Enamul Haque Junior as youngest Bangladeshi to do so, youngest New Zealand bowler is Daniel Vettori, youngest Indian bowler to take 5 wickets in Ravi Shastri, youngest Zimbabwe bowler is Elton Chigumbura, Youngest Srilankan is Ravindra Pushpakumara, youngest Australian bowler to take 5 wicket in a test match innings is John James Ferris followed by youngest South African = Michael Melle.
Since following list is limited to only teenage bowlers who have taken five wickets in an innings, the names to miss out is youngest West Indies bowler = Alf Valentine = 20 years and 41 days old when he took 8/104 versus England at Manchester back in year 1950. Youngest England bowler to take 5 wickets is Bill Voce. He got 7/70 against West Indies back in year 1930 when he was aged only 20 years and 177 days.
Youngest bowler to take 10 wicket haul testis Enamul Haque Junior of Bangladesh who got 7 for 95 and then 5 for 105 in a test match against Zimbabwe at Dhaka back in January 2005. Enamul Haque broke Wasim Akram (Pakistan) record who was only 18 years and 251 days when he took 10 for 128 in two innings against New Zealand at Dunedin back in February 1985.