Used on c-135 stratolifter aircraft. 3a 3rd end bulkhead thread class 12 3rd end bulkhead thread quantity per inch anodize surface treated unj 3rd end bulkhead thread series
Used on grumman a-10 aircraft. 3a 1st end bulkhead thread class 12 1st end bulkhead thread quantity per inch anodize surface treated unj 1st end bulkhead thread series