The ETA 2824-2 is one of the most important automatic mechanical movements for movement-led watch case design.
It is widely used as a reference calibre because it combines a standard 25.60 mm movement diameter, approximately 4.60 mm movement height, automatic winding, central seconds, date, hand-winding, and hacking seconds in a compact and well-known movement architecture.
For HorologyCAD, the ETA 2824-2 is important for another reason: it helps explain the case-design relationship between legacy ETA architecture and modern alternatives such as the Sellita SW200-1.
This page explains the ETA 2824-2 from a watch case design perspective.
It does not treat the movement as a specification list only.
It explains what the movement dimensions mean for internal case geometry, radial clearance, axial clearance, crown and stem alignment, rotor clearance, caseback depth, dial stack planning, movement securing, and manufacturable case architecture.
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Manufacturer Technical Basis
The ETA 2824-2 is an 11½ ligne automatic mechanical movement. Common technical references list the movement at 25.60 mm diameter, 4.60 mm height, 25 jewels, 28,800 vibrations per hour, and roughly 38 to 42 hours of power reserve. Caliber Corner lists the ETA 2824-2 with 25.6 mm diameter, 4.6 mm thickness, 25 jewels, 28,800 bph / 4 Hz, and about 38 hours of power reserve; Grail Watch Reference lists 25.60 mm diameter, 4.60 mm height, 25 jewels, 28,800 A/h, and 42 hours reserve.
Key published technical values include:
movement type: automatic mechanical movement
diameter: 25.60 mm
height: approximately 4.60 mm
ligne size: 11½ ligne
jewels: commonly 25
frequency: 28,800 vph / 4 Hz
power reserve: approximately 38–42 hours
functions: hours, minutes, central seconds, date
architecture: automatic movement with central rotor
The ETA 2824-2 belongs to the same broad 25.60 mm movement diameter class as the Sellita SW200-1 and ETA 2892-A2.
The key difference is height and architecture.
The ETA 2824-2 is thicker than the ETA 2892-A2 and broadly comparable in case-design class to the SW200-1. That makes it useful for understanding standard automatic case architecture, rotor clearance, caseback depth, movement height, and tolerance behaviour.
Core ETA 2824-2 Dimensions
The most important ETA 2824-2 dimensions for watch case design are:
diameter: 25.60 mm
height: approximately 4.60 mm
movement family: automatic
ligne size: 11½ ligne
winding: automatic, with hand-winding
frequency: 28,800 vph
power reserve: approximately 38–42 hours
jewels: commonly 25
date: yes
central seconds: yes
rotor: yes
For case design, the most important values are:
movement diameter
movement height
stem axis
rotor envelope
dial-side stack
date display position
movement securing method
The movement diameter controls internal case geometry, movement holder design, radial clearance, and movement seating.
The movement height controls axial clearance, case thickness, caseback depth, rotor clearance, dial height, hand stack planning, and retention strategy.
The ETA 2824-2 should therefore be treated as a complete movement-led case-design input, not as a simple 25.60 mm round object.
Why the ETA 2824-2 Matters for Case Design
The ETA 2824-2 matters because it became one of the most familiar automatic movement references in modern watch design.
Its dimensions are important not only for direct ETA 2824-2 cases, but also for understanding cases built around related or successor movements.
For watch case design, the ETA 2824-2 helps explain:
standard 25.60 mm automatic movement architecture
movement-to-case fit
automatic rotor clearance
caseback depth
crown and stem alignment
movement holder strategy
radial clearance
axial clearance
dial-side stack control
tolerance planning
comparison with SW200-1 case design
The movement is compact enough for moderate case sizes, but thick enough that axial stack control remains important.
It is not a thin automatic movement like the ETA 2892-A2.
It is a standard automatic reference movement.
Supporting pages:
→ Movement-Led Watch Case Design
→ Watch Movement Dimensions Explained
→ Watch Case Design System
Movement Diameter and Internal Case Geometry
The ETA 2824-2 has a 25.60 mm movement diameter.
This dimension does not mean the case cavity should be exactly 25.60 mm.
The case must also account for:
radial clearance
movement holder geometry
movement seating
anti-rotation control
case machining tolerance
surface finishing allowance
assembly behaviour
service access
case wall thickness
The movement must be located accurately without being forced into the case.
A correct ETA 2824-2 case defines the movement position through controlled internal geometry, not through loose placement inside a generic cavity.
Supporting pages:
→ Internal Case Geometry & Movement Cavity Sizing
→ Radial Clearance
→ Movement to Case Fit
Movement Height and Case Thickness
The ETA 2824-2 is commonly listed at approximately 4.60 mm high.
That height is important because it places the movement in a thicker automatic category than the ETA 2892-A2.
The final case thickness must account for:
caseback internal clearance
rotor clearance
movement height
movement seating height
dial thickness
dial seat height
hand stack height
hand-to-crystal clearance
crystal thickness
bezel or crystal retention geometry
gasket compression allowance
The movement height is only one part of the full axial stack.
A case designed only around the 4.60 mm movement height will usually be incomplete.
The ETA 2824-2 requires enough vertical space for rotor movement, caseback clearance, dial-side clearance, and proper retention.
Supporting pages:
→ Movement Height vs Case Thickness
→ Axial Clearance
→ Hand Stack Height and Clearance Requirements
Rotor Clearance and Caseback Planning
The ETA 2824-2 is an automatic movement, so rotor clearance is a core design requirement.
The caseback must not be lowered only to reduce external case thickness.
It must protect the rotor envelope and allow for:
rotor movement
rotor endshake
movement manufacturing variation
caseback tolerance
gasket compression
shock behaviour
assembly variation
surface finishing effects
Rotor interference can cause scraping, poor winding performance, noise, drag, visible wear, and movement damage.
The caseback is therefore not simply a rear cover.
It is part of the movement-protection and axial-clearance system.
Supporting pages:
→ Rotor Clearance Requirements for Automatic Movements
→ Watch Caseback Design and Fit
→ Water Resistance Engineering in Watch Cases
Stem Height and Crown Alignment
The stem height of the ETA 2824-2 defines where the crown and stem axis must pass through the case.
The crown tube position should not be chosen from external styling first.
Incorrect crown and stem alignment can cause:
stem bending
rough winding feel
poor setting action
keyless works stress
case tube misalignment
crown sealing problems
premature wear
movement shift during use
Because the ETA 2824-2 includes hand-winding as well as automatic winding, crown feel and stem alignment remain important.
The case must define the crown tube position from the movement datum.
Supporting pages:
→ Crown and Stem Alignment in Watch Cases
→ Crown Tube Positioning & Geometry
→ Crown Tube Installation & Tolerances
Dial, Hands, Date, and Crystal Stack
The ETA 2824-2 commonly includes central hours, minutes, central seconds, and date.
The dial-side stack must account for:
dial thickness
dial seating height
date window alignment
dial support
hand stack height
hand-to-crystal clearance
rehaut height
crystal internal clearance
crystal retention geometry
The case cannot be designed only from the movement body.
The dial, hands, date display, rehaut, and crystal must be resolved as part of the complete case stack.
If the dial-side stack is uncontrolled, the hands may contact the crystal, the date window may misalign, or the total case height may increase unnecessarily.
Supporting pages:
→ Dial Seat Geometry
→ Hand Stack Height and Clearance Requirements
→ Dial to Crystal Clearance
Movement Securing and Retention
The ETA 2824-2 must be retained securely inside the case.
The securing system must prevent:
radial movement
axial lift
rotation
dial shift
stem loading
caseback pressure transfer
movement stress during assembly
Movement securing may involve a movement holder, spacer ring, clamps, screws, retaining ledges, caseback control, or a combined system.
The movement should not be allowed to float radially.
It should not be compressed accidentally between the dial side and caseback.
Retention must be designed deliberately as part of the internal case architecture.
Supporting pages:
→ Movement Securing Methods
→ Axial Retention & Movement Stack Control
→ Internal Case Geometry & Movement Cavity Sizing
ETA 2824-2 and SW200-1 Case Design Relationship
The ETA 2824-2 is especially useful because it helps explain the SW200-1 case-design category.
The Sellita SW200-1 is commonly treated as an ETA 2824-2 alternative in many watch design contexts. From a case architecture perspective, both movements sit in the same broad 25.60 mm automatic category, with similar case-design concerns: radial clearance, axial clearance, rotor clearance, crown/stem alignment, movement securing, and caseback planning.
That does not mean every component or detail should be assumed identical.
A case should always be designed from the exact movement data being used.
But the ETA 2824-2 helps explain why SW200-1-style case architecture belongs to a familiar standard automatic movement class.
Supporting pages:
→ SW200-1 Dimensions & Technical Data
→ SW200-1 Case Design Guide
→ SW200-1 Case Design Constraints
ETA 2824-2 Compared With ETA 2892-A2
The ETA 2824-2 and ETA 2892-A2 both sit in the 25.60 mm diameter class, but they create different vertical case-design problems.
The ETA 2824-2 is commonly listed at approximately 4.60 mm high, while the ETA 2892-A2 is commonly listed at approximately 3.60 mm high. Caliber Corner lists the ETA 2824-2 at 4.6 mm thickness, and public technical listings commonly describe the ETA 2892-A2 as approximately 3.60 mm high.
That difference affects:
case thickness potential
caseback depth
rotor clearance planning
dial-side stack freedom
stem height relationship
overall proportion control
thin-case design strategy
The ETA 2824-2 is not the thinner option.
It is the more standard automatic reference for robust, familiar case architecture.
Supporting pages:
→ ETA 2892-A2 Dimensions & Technical Data for Watch Case Design
→ ETA 2892-A2 Case Design Guide
→ Movement Height vs Case Thickness
What the Manufacturer Data Does Not Tell You
Manufacturer movement data gives essential dimensions, but it does not design the watch case.
The datasheet does not fully define:
how much radial clearance to use
how the movement should be retained
how much rotor clearance is safe
how the caseback should be shaped
how gasket compression affects total height
how the dial stack should be controlled
how machining tolerance affects fit
how finishing changes dimensions
how the crown tube should be integrated into the case
how the case should be validated before production
The published ETA 2824-2 dimensions are the starting point.
They are not the complete case architecture.
Supporting pages:
→ Watch Movement Dimensions Explained
→ Watch Case Design Fundamentals
→ Watch Case Design System
Common ETA 2824-2 Case Design Mistakes
Common mistakes include:
treating 25.60 mm as the finished case cavity size
forgetting rotor clearance
using movement height as the only case-thickness input
placing the crown visually instead of from the stem axis
allowing the movement to float radially
using uncontrolled caseback compression as retention
ignoring dial and hand clearance
misaligning the date window
underestimating gasket compression
failing to plan tolerance stack behaviour
assuming ETA 2824-2 and SW200-1 cases are automatically interchangeable without checking details
Most of these failures come from treating the movement as a component to insert into a case rather than the foundation that defines the case.
Supporting pages:
→ Why Most Watch Case Designs Fail
→ Failure Cascade Analysis
→ Design Validation Checklist
Case Design Implications
For ETA 2824-2 case design, the case should be planned around:
25.60 mm movement diameter
4.60 mm movement height
controlled radial clearance
automatic rotor clearance
caseback depth
stem height and crown tube position
dial-side stack height
date display alignment
hand-to-crystal clearance
movement securing
gasket compression
manufacturing tolerances
assembly sequence
The ETA 2824-2 is especially useful where a standard automatic movement architecture is required.
But the movement only provides the foundation.
The case architecture determines whether that foundation becomes functional, manufacturable, and reliable.
HorologyCAD Design Position
Within the HorologyCAD system, the ETA 2824-2 is best understood as a standard 25.60 mm automatic reference movement.
It is useful for explaining:
standard automatic case architecture
relationship to SW200-1-style case design
radial and axial clearance planning
automatic rotor clearance
caseback depth
crown alignment
movement holder design
date and dial-side stack control
manufacturable automatic case geometry
The ETA 2824-2 should not be approached as a generic automatic movement.
It should be approached as a reference calibre that defines a familiar but still constraint-driven case design problem.
A correct ETA 2824-2 case begins with the movement dimensions, but it must continue through clearance planning, stem alignment, rotor protection, movement retention, sealing, tolerance control, and validation.
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