25O5203 up for sale is a lot of 10 pieces older military vintage aircraft self locking nuts , hard to find these style of nuts these days , these came from a closed older military surplus place years ago , these are covered under military code AN364-632A and also covered under military NSN 5310-00-905-8451 , but if you search for this NSN you will find a newer version of this nut the military uses now and the design is different , so these old clinch type are hard to find , great small nuts for a period restoration or to get a look you want on a small project , these have a 6-32 internal thread with the clinch area on one side and the hex measures 0.310 the total thickness is 0.135 the small clinch area is 0.205 diameter x about 0.062 high , these appear to have some type of plating over the steel that looks white and chalky , very nice nuts for many uses , see our store we try to add new items like this each week to our store here on ebay , thank you rwk