National Stock Number (NSN) 5305-00-818-0517 (5305008180517) Parts List

Item Name	Screw Cap Socket Head
Federal Supply Group (FSG)	Hardware and Abrasives
Federal Supply Class (FSC)	5305 Screws
National Item Identification Number (NIIN)	00-818-0517 (008180517)
NCB Code	USA (00)
Manufacturer	Aeronautical Standards Group, Nylok Corporation, Schaefer Marine Inc

Part Number	Manufacturer	Item Name	Cage Code	RFQ
AN505-2-4	aeronautical standards group	screw cap socket head	88044	RFQ
NK505-2-4	nylok corporation	screw cap socket head	26233	RFQ
NK505-2R4	schaefer marine inc	screw cap socket head	02165	RFQ

MRC	Criteria	Characteristic
AAJD	THREAD CLASS	2A
AASA	THREAD LENGTH	0.250 INCHES MINIMUM
AASL	HEAD DIAMETER	0.150 INCHES MINIMUM AND 0.172 INCHES MAXIMUM
AHYM	NOMINAL THREAD DIAMETER	0.086 INCHES
MATT	MATERIAL	STEEL OVERALL
SFTT	SURFACE TREATMENT	CADMIUM OVERALL
AAJF	THREAD DIRECTION	RIGHT-HAND
AASB	FASTENER LENGTH	0.250 INCHES NOMINAL
AASK	HEAD STYLE	FLAT COUNTERSUNK
AAUM	LOCKING FEATURE	PATCH THREADS OR STRIP THREADS
ABQZ	INTERNAL DRIVE STYLE	CROSS RECESS TYPE 1
CMLP	THREAD QUANTITY PER INCH	56
CRSQ	COUNTERSINK ANGLE	80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM
THSD	THREAD SERIES DESIGNATOR	UNC