Haynes Publishing's adjusted pre-tax profits rose by 120% to £1.1m in the six months to the end of November.
Group revenues were up 21% at £16.9m and adjusted EBITDA increased by 29% to £5.3m.
Adjusted basic earnings per share rose by 151% to 5.3p.
The interim dividend is maintained at 3.5p per share.
Chairman Eddie Bell said: 'I am pleased to report that this is the third consecutive set of results where Haynes has demonstrated strong underlying revenue and profit growth since we implemented our global operational, cost and structure review in 2015/16.