PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

16991-4C20Screw,machine

Sps Technologies, Llc Dba PB Fasteners · NSN 5305-01-481-3940 · FSC 5305 · No Item Name Available
Verified by PartsTable
NSN 5305-01-481-3940 — this item is cataloged by the U.S. Government under National Stock Number 5305-01-481-3940. Primary manufacturer part number: 16991-4C20.
Features
  • Screw,machine — FSC 5305
  • Thread Direction: RIGHT-HAND
  • Countersink Angle: 80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM
  • Head Diameter: 0.480 INCHES MINIMUM AND 0.531 INCHES MAXIMUM IN
  • Screw Material: STEEL CORROSION RESISTING
  • Thread Quantity Per Inch: 20
  • Head Style: FLAT COUNTERSUNK
  • Thread Series Designator: UNRC
Applications
  • Structural fastening and assembly
  • Equipment mounting
  • Panel and housing attachment
General Description

The Screw,machine, cataloged under National Stock Number 5305-01-481-3940, is classified within Federal Supply Class 5305 (No Item Name Available) of the Hardware and Abrasives group. The primary manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. Government technical data includes 10 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 2 manufacturers, enabling identification through both NSN and commercial part number lookups. 9 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN5305-01-481-3940
Primary Part Number16991-4C20
Item NameScrew,machine
FSC / FSG5305 / 53 — No Item Name Available
ManufacturerSps Technologies, Llc Dba PB Fasteners
StatusACTIVE
Thread DirectionRIGHT-HAND
Countersink Angle80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM
Head Diameter0.480 INCHES MINIMUM AND 0.531 INCHES MAXIMUM IN
Screw MaterialSTEEL CORROSION RESISTING
Thread Quantity Per Inch20
Head StyleFLAT COUNTERSUNK
Thread Series DesignatorUNRC
Nominal Thread Diameter0.250 INCHES IN
Thread Class3A A
Fastener Length1.250 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 9
3040-00-720-1456804792 INTERCHANGEABLE
Shaft,input
Fwd Seagrave Holdings Lp
5940-00-849-169610015366-12 INTERCHANGEABLE
Terminal,lug
Us Army Aviation and Missile Command
5340-01-109-282831094 INTERCHANGEABLE
Plug Assembly
Garrison Manufacturing Inc
3040-01-129-3028 INTERCHANGEABLE
Shaft,shouldered
5310-01-292-0087 INTERCHANGEABLE
Washer,special
6625-01-407-255531094 INTERCHANGEABLE
Ammeter
Esab Group, Inc., the Dba Esab Welding and Cutting Products Div Esab Welding and Cuttng
6515-01-516-1806310.94 INTERCHANGEABLE
Chuck,quick Coupling
Depuy Synthes Sales Inc Dba Depuy Synthes Trauma Div Depuy Synthes Sales, Inc., D/b/a Depuy Synthes Trauma
5325-01-674-999431094 INTERCHANGEABLE
Ring,retaining
Consolidated Sewing Machine Corp
6150-01-728-062631-094 INTERCHANGEABLE
Cable Assembly,special Purpose,e
Konrad Marine Inc Div Konrad Marine
Cross-Reference Index
Part NumberManufacturer
16991-4C20 PRIMARY Sps Technologies, Llc Dba PB Fasteners (USA)
31094 Sps Technologies Inc Unbrako Div (USA)
31094 Sps Technologies, Llc Dba PB Fasteners (USA)
Related Parts
3040-00-720-1456INTERCHANGEABLE
SHAFT,INPUT
804792
5940-00-849-1696INTERCHANGEABLE
TERMINAL,LUG
10015366-12
5340-01-109-2828INTERCHANGEABLE
PLUG ASSEMBLY
31094
3040-01-129-3028INTERCHANGEABLE
SHAFT,SHOULDERED
5310-01-292-0087INTERCHANGEABLE
WASHER,SPECIAL
6625-01-407-2555INTERCHANGEABLE
AMMETER
31094
6515-01-516-1806INTERCHANGEABLE
CHUCK,QUICK COUPLING
310.94
5325-01-674-9994INTERCHANGEABLE
RING,RETAINING
31094
6150-01-728-0626INTERCHANGEABLE
CABLE ASSEMBLY,SPECIAL PURPOSE,E
31-094

Frequently Asked Questions

What is NSN 5305-01-481-3940?

NSN 5305-01-481-3940 is a Screw,machine, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5305 (No Item Name Available). Status: active.

What are the part numbers for NSN 5305-01-481-3940?

NSN 5305-01-481-3940 has 3 cross-referenced part numbers: 16991-4C20 (Sps Technologies, Llc Dba PB Fasteners), 31094 (Sps Technologies Inc Unbrako Div), 31094 (Sps Technologies, Llc Dba PB Fasteners).

What NSN replaces 5305-01-481-3940?

There are 9 known substitutes for 5305-01-481-3940: 3040-00-720-1456, 5940-00-849-1696, 5340-01-109-2828 and 6 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 16991-4C20?

Key specifications for 16991-4C20: Thread Direction: RIGHT-HAND; Countersink Angle: 80.0 DEGREES MINIMUM AND 82.0 DEGREES MAXIMUM; Head Diameter: 0.480 INCHES MINIMUM AND 0.531 INCHES MAXIMUM IN; Screw Material: STEEL CORROSION RESISTING. 10 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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