The Stridsvagn Strv m/40 Light Tank was the first Swedish combat tank to be ordered in useful quantity - its total manufacture output running 180 vehicles. The design was a further evolution of the original L-60 tank which emerged from work begun in 1934. The line ultimately included the Strv m/38, Strv m/39, and the still-to-come Strv m/42. As the war in Europe spread into neighboring Norway and Finland, the Swedish government moved on attempting to provide a viable defense should it itself be invaded despite their neutral position in the war.
The evolving war situation also helped the Swedes to evolve their own tank design and doctrine approach without exposure to direct combat. As such, the m/40 was something of a refined m/39 featuring a new turret design (with revised gun mantlet), extra armor protection, and a useful commander's cupola. The crew remained three - driver, commander, and gunner, while the five-wheeled running gear was retained as was the primary armament of 1 x 37mm Bofors gun along with 2 x 8mm Ksp m/39 machine guns - one machine gun coaxially mounted and the other in the bow.
The m/40 appeared in two marks - the m/40L by AB Landsverk and the m/40K by Landsverk subcontractor Karlsverk ("Karlstads Mekaniska Verkstad"). Differences between the two were notable - the L-model weighing 9.1 tons, featuring armor protection up to 15mm, and powered by a Scania-Vabis 1664 series engine of 142 horsepower. The K-model weighed in at 10.9 tons, held armor protection up to 50mm thick, and was driven by a Scania-Varbis L603 engine of 162 to help content with the added weight. Dimensions were consistent across the two vehicles - length of 4.9 meters, width of 2 meters, and height of 2 meters. Road speeds were equal at 28 miles per hour. Armament remained the same as in earlier Swedish tank offerings - a single 37mm Bofors main gun with 2 x 8mm Ksp m/39 anti-infantry machine guns. The running gear was carried over as well - four road wheels to a hull side with the drive sprocket at front and track idler at rear. Two track return rollers were also used.
The stock of available m/40 tanks grew from 1942 to 1944. Total production numbered 180 vehicles - 100 by AB Landsverk and 80 of the improved form by Karlsverk.