They were found by the court to be members of the Province of Giza, a branch of the Islamic State group, and involved in a series of deadly attacks last year, the source said.
Sixteen others received life sentences of 25 years, while 15 were jailed for five to 15 years.
"The defendants used arms, explosives and bombs" in the attacks, the head of the military court said, quoted in the government newspaper Akhbar al-Youm.
Those convicted have the right to appeal their sentences at the military supreme court, an army official told AFP on the condition of anonymity, confirming the convictions reported in state media.
Seventeen defendants were acquitted in the military trial.
Since the ousting of Islamist president Mohamed Morsi in 2013, hundreds of police officers, soldiers and civilians have been killed in jihadist attacks.
The Egyptian army launched a large-scale "Sinai 2018" operation in February, at the request of President Abdel Fattah al-Sisi, aimed at ridding the peninsula of IS militants.
