The Nikkorex F, introduced in 1962, was the second interchangeable-lens SLR sold by Nikon, but it was manufactured by Mamiya.
Along with dropping the leaf shutter design of the other Nikkorex products, the Nikkorex F was the first production camera to use the Copal Square shutter, a rugged design used in many future cameras by Nikon and other manufacturers. The shutter also offered a faster flash sync speed of 1/125th of a second compared to the Nikon F. Along with a different shutter, the Nikkorex F used a hinged back for more convenient film loading.
In 1965, the first of the Nikkormat series was introduced, a Nikon-built amateur market camera using a Copal Square shutter. The Nikkorex F was discontinued in 1966, and Mamiya sold the design to Ricoh, which produced the related Ricoh Singlex and Sears SL11.