Abstract: An air chuck molded of synthetic resin material having a body with bores therein for the flow of air through the body. A check valve is provided in one of the bores and an end cap is threaded into this one bore to maintain the check valve in its desired position within the bore. This one bore has internal threads therein recessed from the outer end of the air chuck body so that, with the cap threaded into the bore, the cap is flush with or somewhat recessed into the bore whereby the internal threads in the air chuck body are protected from damage.