Machine Bolt P/N MS21250

Specifications

Thread class

3A

Thread direction

Right-Hand

Thread length

0.579 in minimum

Fastener length

1.678 in (nominal)

Head height

0.348 in (nominal)

Width between flats

0.375 in (nominal)

Extended washer diameter

0.521–0.531 in

Extended washer thickness

0.82 in (nominal)

Nominal thread diameter

Inches 0.3125

Nonstandard thread pitch diameter

Inches -0.05 to 0.08

Minimum tensile strength

Pounds Per Square Inch 180000

Hardness rating

Overall Rockwell C Minimum 39.0 and Rockwell C Maximum 43.0

Part name assigned by controlling agency

Bolt,Tension,Steel,External Wrenching,Flanged

Special features

12-POINT, 180 Ksi Ftu, 450 F

Material

Overall Steel Comp E4340 or Steel Comp 8740 or Steel Comp 4140

Surface treatment

Overall Cadmium and Chromate

Surface treatment document and classification

Overall Fed Spec Single Treatment Response QQ--416,TY2,CL3

Thread series designator

Unified National Joint Fine (Unjf)

From the federal catalog's item characteristics for this NSN. Confirm critical dimensions against your part or drawing before ordering.

Cross-reference part numbers

MS21250 MS21250-05008 6736617-6

Also referenced as

6736617

Older, superseded, advisory or drawing numbers the federal catalog associates with this NSN — the ones in an old manual. They find the item; confirm the current part number when you order.

Shown for identification only. SECO can quote against any of these numbers.

Logistics data

Source of supply	SMS DLA Land and Maritime, Columbus, Ohio
Acquisition advice code	Z Insurance/numeric stockage objective — held by the government as insurance stock for contingencies, not for routine issue. SECO has 8 on the shelf
Unit of issue	EA each
Demilitarization code	A Demilitarization not required — non-munitions-list item
Controlled inventory code	U Unclassified
Hazardous material indicator	N No hazardous material

Source: public FLIS/PUB LOG cataloging data.

Why buy from SECO

These quantities sit on our own shelves — we are a stocking supplier, not a broker sourcing after you order. Condition-coded stock, formal quotes with NSN/PN on the paperwork, POs and GPC welcome, fast U.S. shipping.

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FAQ

What is NSN 5306-01-616-4012?
NSN 5306-01-616-4012 (5306016164012) — Machine Bolt: SECO Parts has 8 in stock in Augusta, GA, on our own shelf. It is the NATO Stock Number for machine bolt in federal supply class 5306 (Bolts).

Is NSN 5306-01-616-4012 available?
SECO Parts has 8 in stock in Augusta, GA — order or request a quote below.

How much does NSN 5306-01-616-4012 cost?
SECO typically prices parts like NSN 5306-01-616-4012 at $25–$40 each: an estimate from the government catalog price and what SECO has charged for similar parts. It is not a quote — request one for your price, usually answered the same business day. Quote lines carry a $50 minimum.

What does NSN 5306-01-616-4012 fit?
The federal catalog lists NSN 5306-01-616-4012 as used on: MK 7 Mod 1 RA.

What part numbers cross-reference to NSN 5306-01-616-4012?
Part numbers that cross-reference this NSN include MS21250, MS21250-05008, 6736617-6. It is also referenced by older, superseded or advisory numbers: 6736617. SECO can quote against any of them.