B-12-5-56

View detailed technical data, stock status, and sourcing information for: B-12-5-56
DODParts.com distributes related products varnishes dopes paints, aircraft parts and consumables, electrical parts, fittings and other components for the aerospace and defense industries. Submit the short price quote form for part B-12-5-56 to receive an up to date pricing and availability quote by email.

Federal Supply Group

Hardware and Abrasives

Federal Supply Classification

5305 Screws

National Stock Number

5305-01-122-5478

Item Name Code

18257

Assigment Date

11/24/1981 (44 years ago)

An externally threaded fastener designed for insertion into holes in assembled parts, for mating with a preformed internal thread and for tightening or releasing by torquing the head. The threaded and unthreaded portions are both of the same nominal diameter of 0.190 inch (5 mm) or larger. Head dimensions and sizes of threaded and unthreaded portions shall conform to internationally recognized fastener standards. The thread length being the controlled dimension, the grip length is not specified. A locking feature may be incorporated in the design of the head or threads. The head is not designed to be held or driven with an inserted driver or by the thumb and fingers. Excludes:bolt,machine; bolt,externally relieved body; bolt,internal wrenching; and screw,cap,socket head.

4.000 inches nominal fastener length, 1.250 inches nominal thread length, right-hand thread direction, hexagon head style, 3a thread class

Product Characteristics

Below you’ll find the complete technical specifications and performance data for this part, including material details and compliance information.

Thread Class: 3a
Thread Direction: right-hand
Thread Length: 1.250 inches nominal
Fastener Length: 4.000 inches nominal
Head Style: hexagon
Head Height: 0.302 inches minimum and 0.323 inches maximum
Width Between Flats: 0.736 inches minimum and 0.750 inches maximum
Nominal Thread Diameter: 0.500 inches
Thread Quantity Per Inch: 13
Special Features: furnished with one nut
Material: steel corrosion resisting overall
Thread Series Designator: unc

Related Parts

This NSN group includes multiple components designed to meet specific performance and operational standards. Each listing provides detailed specs, functionality data, and replacement compatibility information:

Part Number	Name
B-12-5-56	Hexagon Head Cap Screw
LSD37-200-4692817 PIECE 22	Hexagon Head Cap Screw

FAQs

Find helpful answers about installation, operation, maintenance, compliance, and troubleshooting.

What is the FSCG of the NSN 5305-01-122-5478?

The FSCG of the NSN 5305-01-122-5478 is 5305

Does the NSN 5305-01-122-5478 have a Schedule B code assigned?

Yes, the Schedule B code is 7318152000

Does NSN 5305-01-122-5478 require demilitarization?

Items subject to the export administration regulations (ear) in parts 730-774 of title 15, code of federal regulations (cfr) (ccli or ear99) and determined by dod to present a low risk when released out of dod control. No demil, mut, or end use certificate is required. May require an export licensefrom doc.

Does NSN 5305-01-122-5478 contain precious materials?

Item does not contain precious metal.

Does NSN 5305-01-122-5478 contain hazardous materials?

Indicates there is no data in the hmirs and the nsn is in a fsc not generally suspected of containing hazardous materials.

When the NSN 5305-01-122-5478 was assigned to the Federal Catalog?

It was assigned 44 years ago, on Tue, Nov 24, 1981