Hamilton managed 97 circuits as Mercedes continued to show off their bulletproof reliability and was fifth on the timesheets.
Valtteri Bottas will take over testing duties from Hamilton for Mercedes on Friday afternoon.
Ferrari’s Kimi Raikkonen meanwhile set the second-fastest time of the winter as he followed team-mate Sebastian Vettel as the only drivers to dip under the one minute and 18 seconds mark.
Raikkonen’s best effort of 1:17.221 was less than four hundredths of a second slower than Vettel’s impressive lap from Thursday.
But it was bad news for McLaren who endured yet another disastrous start to testing after Fernando Alonso broke down inside the first hour.
The double world champion was completing only his seventh lap when he stopped at turn seven of Barcelona’s Circuit de Catalunya.
McLaren are changing Alonso’s engine as they investigate the cause of his car’s failure, but the Spaniard is set to lose further valuable track time.
McLaren’s latest issue marks the third day of this week’s concluding four-day test in Spain in which the British team have encountered problems.
The new Formula One campaign gets under way in Melbourne in a fortnight’s time.
LATEST F1 NEWS – FOLLOW THE BEST STORIES FROM AROUND THE F1 WORLD