The "Erzherzog Karl" class carried a primary armament made by Škoda Works. On each ship, there were four /40 caliber guns in two twin turrets on the centerline. These guns were an Austro-Hungarian replica of the 24 cm/40 (9.4") Krupp C/94, which was used on the "Habsburg"s. The guns could be depressed to −5° and elevated to 30°. The arc of fire of the guns was 300°, or 150° in each direction. Each gun required a crew of twenty men. At maximum elevation, the gun could fire a shell . They could fire three to four armor-piercing shells per minute at a muzzle velocity of . Each of the guns weighed at least .