Panzer III ausf F 61316
Essentially, the Ausf F tank was identical to the Ausf E tank, as it was designed to be a mass-produced effective combat vehicle. In January 1939, the production order for the Ausf F was reduced by 250 units, since orders for the improved Ausf G and H models had already been placed. The key change made to the Ausf F was to its ignition system. During the early stages of production, cast air-intakes were added to the upper hull plate to enable air circulation for brake and final-drive cooling. The majority of Ausf F tanks were equipped with a 3.7cm KwK gun, but about 100 were fitted with the 5cm KwK L/42 and external mantlet as original equipment. From August 1940 until 1942, many of the remaining Ausf F tanks were converted from the 3.7cm KwK to the 5cm KwK L/42 gun and external mantlet. At the same time, orders were issued to add 30mm plates to the hull and superstructure for additional armor.
The Ausf F tanks were quickly issued to the Panzer regiments from late 1939 to early 1940, as soon as they were produced. On 10 May 1940, a total of 348 Pz Kpfw III tanks, mostly Ausf E and F, but with a few Ausf G, were deployed with seven Panzer divisions on the Western Front. At that time, there were two light tank companies in each tank detachment, but the actual number of Pz Kpfw III tanks varied greatly between the seven Panzer divisions, ranging from five to seventeen in each light tank company. The last known combat action involving an Ausf F tank occurred in June 1944, when they were used by the 116th Panzer Division.