PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

GG-B-500Block,tackle

Federal Specifications Promulgated by General Services Administration Washington DC · NSN 3940-00-239-8778 · FSC 3940 · No Item Name Available
Verified by PartsTable
NSN 3940-00-239-8778 — this item is cataloged by the U.S. Government under National Stock Number 3940-00-239-8778. Primary manufacturer part number: GG-B-500.
Features
  • Block,tackle — FSC 3940
  • Surface Treatment Document and Classification: MIL-Z-17871 MIL SPEC SINGLE TREATMENT RESPONSE SHEAVE
  • Maximum Tackle Diameter Accommodated: 0.625 INCHES IN
  • Tackle Locking Device: NOT INCLUDED
  • Sheave Quantity: 2
  • Sheave Bearing Lubrication Method: SELF-LUBRICATED
  • Antitoppling Device: NOT INCLUDED
  • Block Type: REGULAR
Applications
  • Applications requiring Steel Center Pin construction
General Description

The Block,tackle, cataloged under National Stock Number 3940-00-239-8778, is classified within Federal Supply Class 3940 (No Item Name Available) of the Materials Handling Equipment group. The primary manufacturer of record is Federal Specifications Promulgated by General Services Administration Washington DC. Government technical data includes 28 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN3940-00-239-8778
Primary Part NumberGG-B-500
Item NameBlock,tackle
FSC / FSG3940 / 39 — No Item Name Available
ManufacturerFederal Specifications Promulgated by General Services Administration Washington DC
StatusACTIVE
Surface Treatment Document and ClassificationMIL-Z-17871 MIL SPEC SINGLE TREATMENT RESPONSE SHEAVE
Maximum Tackle Diameter Accommodated0.625 INCHES IN
Tackle Locking DeviceNOT INCLUDED
Sheave Quantity2
Sheave Bearing Lubrication MethodSELF-LUBRICATED
Antitoppling DeviceNOT INCLUDED
Block TypeREGULAR
Becket TypeTHIMBLE
Tackle Accommodated TypeWIRE ROPE
Attachment StyleFLATTED LOOSE SWIVEL EYE WITH SWIVEL HOOK
Sheave Outside Diameter10.000 INCHES NOMINAL IN
Becket Quantity1
Surface TreatmentZINC CENTER PIN
MaterialSTEEL CENTER PIN
Surface Treatment Document and ClassificationMIL-Z-17871 MIL SPEC SINGLE TREATMENT RESPONSE CENTER PIN
Material Document and ClassificationQQ-S-681 FED SPEC SINGLE MATERIAL RESPONSE SHEAVE
Bearing TypePLAIN
Surface Treatment Document and ClassificationMIL-Z-17871 MIL SPEC SINGLE TREATMENT RESPONSE SHELL
Style DesignatorDIAMOND PATTERN
Surface TreatmentZINC SHEAVE
Material Document and ClassificationMIL-B-5687 TYPE 1 COMP A MIL SPEC SINGLE MATERIAL RESPONSE BEARING
Nondefinitive Spec/std Data2 TYPE AND A GRADE AND 2 STYLE
MaterialSTEEL SHEAVE
Surface TreatmentZINC SHELL
MaterialSTEEL SHELL
Material Document and ClassificationQQ-S-741 FED SPEC SINGLE MATERIAL RESPONSE SHELL
MaterialCOPPER ALLOY BEARING
Load Rating600.0 POUNDS MAXIMUM LBS
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
3940-00-246-8841 INTERCHANGEABLE
Block,tackle
3940-00-272-9308 INTERCHANGEABLE
Block,tackle
Cross-Reference Index
Part NumberManufacturer
GG-B-500 Federal Specifications Promulgated by General Services Administration Washington DC (USA)
Related Parts
3940-00-246-8841INTERCHANGEABLE
BLOCK,TACKLE
3940-00-272-9308INTERCHANGEABLE
BLOCK,TACKLE

Frequently Asked Questions

What is NSN 3940-00-239-8778?

NSN 3940-00-239-8778 is a Block,tackle, manufactured by Federal Specifications Promulgated by General Services Administration Washington DC, classified under FSC 3940 (No Item Name Available). Status: active.

What are the part numbers for NSN 3940-00-239-8778?

NSN 3940-00-239-8778 has 1 cross-referenced part number: GG-B-500 (Federal Specifications Promulgated by General Services Administration Washington DC).

What NSN replaces 3940-00-239-8778?

There are 2 known substitutes for 3940-00-239-8778: 3940-00-246-8841, 3940-00-272-9308. Verify interchangeability with system specifications before substitution.

What are the specifications of GG-B-500?

Key specifications for GG-B-500: Surface Treatment Document and Classification: MIL-Z-17871 MIL SPEC SINGLE TREATMENT RESPONSE SHEAVE; Maximum Tackle Diameter Accommodated: 0.625 INCHES IN; Tackle Locking Device: NOT INCLUDED; Sheave Quantity: 2. 28 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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