Revenue of A$124.3 million was down 3% on the first half of the 2020 financial year.
EBITDA rose 6% to $33.1 million, while cash from operations jumped 33% to $33.2 million.
Net profit after tax for the half dropped 26% to $13.5 million due to higher depreciation and amortisation charges relating to additional assets to support increasing demand for gyro-related technologies and the Flexidrill and AusSpec acquisitions.
Net cash jumped 84% to $47 million.
Imdex declared a fully franked interim dividend of 1c per share.
CEO Paul House said it was a solid start to the 2021 financial year and the company was outperforming industry growth rates.
House said Imdex's strong balance sheet enabled the company to accelerate targeted research and development in line with demand and leverage opportunities for growth through acquisitions.
"While the opportunity ahead of us is exciting, we remain watchful and ready," he said.
"We are watchful of the current risks posed by COVID and ready to meet the increasing demand for mining-technologies.
"This confluence of risk and opportunities is accelerating long-term structural change in the mining industry."
House said activity increased in most of Imdex's regions, most notably North America and West Africa.
"Our global reach and unrivalled product offering mean we can grow in all market conditions," he said.
Imdex said the increase in exploration and acceleration of investment in decarbonisation metals meant the outlook for mining tech was stronger than it had ever been.
The company signed a joint development agreement with an unnamed tier one mining company to accelerate one of its key rock knowledge sensor technologies for commercial use.
It also has a joint development agreement to accelerate its drilling optimisation tool, Imdex Maghammer, for commercial use. Ground trials under that agreement have started.
Shares in Imdex jumped 7.2% to $1.85, valuing the company at $733.4 million.