5305-00-003-6868, SCREW,CLOSE TOLERANCE

National Stock Number:
5305-00-003-6868

Federal Supply Class:
5305

National Item Identification Number:
000036868

Description:
SCREW,CLOSE TOLERANCE

Detail:
A SCREW, MACHINE or SCREW, CAP, SOCKET HEAD whose unthreaded portion is of specified grip length, plated or unplated, and is machined to a tolerance of one thousandth (0.001 IN.) (0.025 mm) or less of a specific diameter for items (1.000 IN.) (25 mm) or less in diameter. Items over (1.000 IN.) (25 mm) in diameter shall have a tolerance of fifteen ten thousandths (0.0015 IN.) (0.038 mm) or less. The nominal major diameter of the threads shall be at least one thousandth (0.001 IN.) (0.025 mm) below the minimum shank diameter, but not below the minimum major diameter for applicable class of fit, as shown in the Screw Thread Standards, FED STD H28 and/or other nationally recognized standards. The head is designed to be held or driven with an inserted driver. It is not designed for rotation by the thumb and fingers. A locking feature may be incorporated in the design of the head or threads.

Manufacturer Information:

51B581-2-3	0JRC1	NORTHROP GRUMMAN TECHNICAL SERVICES, INC.
51B581-2-3	76823	NORTHROP GRUMMAN SYSTEMS CORPORATION

Techincal Specification:

COUNTERSINK ANGLE	99.5 DEGREES MINIMUM AND 100.5 DEGREES MAXIMUM
FASTENER LENGTH	0.448 INCHES MINIMUM AND 0.495 INCHES MAXIMUM
GRIP LENGTH	0.266 INCHES MINIMUM AND 0.286 INCHES MAXIMUM
GRIP DIAMETER	0.1625 INCHES MINIMUM AND 0.1635 INCHES MAXIMUM
HARDNESS RATING	39.0 ROCKWELL C MINIMUM AND 43.0 ROCKWELL C MAXIMUM OVERALL
HEAD DIAMETER	0.256 INCHES MINIMUM AND 0.261 INCHES MAXIMUM
HEAD STYLE	FLAT COUNTERSUNK
INTERNAL DRIVE STYLE	OFFSET CRUCIFORM (TORQUE SET)
MATERIAL	STEEL COMP E4340 OR STEEL COMP 4340 OR STEEL COMP 4140 OR STEEL COMP 8740 OVERALL
MINIMUM TENSILE STRENGTH	180000 POUNDS PER SQUARE INCH
NOMINAL THREAD DIAMETER	0.164 INCHES
SPECIFICATION/STANDARD DATA	76823-51B581 MANUFACTURERS STANDARD
SURFACE FINISH	32.0 MICROINCHES GRIP
SURFACE TREATMENT DOCUMENT AND CLASSIFICATION	QQ-P-416,TY 2,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL
SURFACE TREATMENT	CADMIUM AND CHROMATE OVERALL
THREAD CLASS	3A
THREAD DIRECTION	RIGHT-HAND
THREAD LENGTH	0.162 INCHES MINIMUM AND 0.229 INCHES MAXIMUM
THREAD QUANTITY PER INCH	32
THREAD SERIES DESIGNATOR	UNJC

Click here to Register for Free 30-day Trial