Description
U.S. Military Heavy Artillery Equilibrator Spring, P/N 8671112-1, NSN 5360-00-867-1112
Item Overview
This U.S. military heavy compression spring is identified by stamped part number 8671112-1 and National Stock Number 5360-00-867-1112. It is a large mechanical counterbalance component intended for artillery equipment. It is not ammunition, a recoil spring, or a vehicle suspension spring. Its dimensions and construction match the 155mm M114-series howitzer.
Identification and Features
Federal catalog data confirms the spring's identity, material, construction, and dimensions. The registered design reference is assigned to U.S. Army TACOM under CAGE 19207; that identifies the Army drawing authority and does not prove which factory made this example. The exact weapon application should therefore be verified from the stamped number and measurements before installation.
- Item: Heavy helical compression spring
- Stamped part number: 8671112-1
- NSN: 5360-00-867-1112
- Federal Supply Class: 5360, coil, flat, leaf, and wire springs
- Material: 9262 spring steel
- Surface treatment: Phosphate
- Style: Cylindrical helical compression spring
- Free length: 45 inches
- Free outside diameter: 13.75 to 14 inches
- Inside diameter: 11.80 to 11.82 inches
- End style: Squared and ground at both ends
- Special end construction: End coils forged to a wedge shape
- Drawing authority: U.S. Army TACOM, CAGE 19207
- Application: Artillery equilibrator service, associated with the 155mm M114 family;
Original Service Function
An equilibrator supports the muzzle-heavy tipping parts of an artillery piece. On the M114 family, the Army used two spring-type equilibrators, one on each side of the howitzer. The springs compressed as the cannon was lowered, slowing and balancing the downward movement. When the crew elevated the cannon, the stored spring energy pushed upward and reduced the effort needed at the elevating handwheel. This counterbalance action helped the crew lay the weapon smoothly and safely without making the spring part of the recoil system.
M114 Howitzer Application
The size, form, and military classification of part 8671112-1 are consistent with a large artillery equilibrator spring, and the M114 technical manual shows similar heavy coil springs inside the weapon's two equilibrator assemblies. However, the exact NSN has not been found in an accessible M114 parts list. Collectors and restorers should match the part number, free length, inside diameter, outside diameter, end style, and mounting arrangement to their equipment before purchase or installation.
M114 Weapon-System History
The weapon later known as the 155mm Howitzer M114 was developed before World War II and entered U.S. service as the 155mm Howitzer M1. It used a split-trail carriage and provided medium artillery support at ranges beyond lighter field guns. The Army redesignated the family M114 in 1962 as part of a wider change in equipment naming. The M114 remained a standard American 155mm towed howitzer through the Korean and Vietnam War periods. Replacement by the M198 began in 1979, but M114-family guns continued in service with allied nations and reserve forces for many years.
Historical Service Use
M1 and M114-series howitzers supported field artillery units in World War II, the Korean War, and the Vietnam War. Crews used these guns for general-support fire with high-explosive, smoke, illuminating, and other authorized 155mm ammunition. Equilibrator springs worked whenever a crew raised or lowered the cannon for firing, travel, inspection, or maintenance. Though largely hidden inside the mechanism, they were essential to controlling the heavy barrel and recoil assembly during normal operation.
Handling and Safety
This is a non-explosive mechanical component, but a spring of this size can be dangerous when compressed or installed. The Army manual warns that M114 equilibrator springs remain under very great compression and that unauthorized disassembly may cause serious or fatal injury. Do not compress, cut, heat, disassemble, or install this spring without the correct fixtures, procedures, and qualified personnel. Its large size and weight also require safe lifting and secure storage.
Condition
This is a military-surplus mechanical part offered for collecting, display, study, or restoration use. Age, storage wear, surface oxidation, finish loss, old preservative, handling marks, and other signs of service or long-term storage may be present. No claim of current serviceability or guaranteed fit is made. This listing is for one spring only; housings, rods, seats, adjusting hardware, and other equilibrator parts are not included unless specifically stated. Please check the pictures for the general condition of the item.
Ideal For
This uncommon large-format Army component is well suited to collections and exhibits focused on U.S. field artillery, heavy military machinery, and the engineering of gun-elevation systems.
- U.S. field artillery collections
- 155mm howitzer displays
- M114 restoration research, subject to fit verification
- Military museums and educational exhibits
- Ordnance maintenance and engineering displays
- Large military-surplus component collections
Approx length 45", Approx width 14", Approx height 14", Approx weight 70lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item’s general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
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