Kason 53 door latch. The model 53 padlocking non safety door latch that can be used on larger walk-in doors where a safety style door latch is not needed. SAFETY WARNING This is not a safety door latch and should not be used where one door is the sole means of exit. The 53 latch is made of cast iron with a kasonized finish. Looking for a safety latch? we have a couple of popular models available the Kason 56 series and the Kason 58 series both are work horses in the food service industry.