It is crucial to understand that , even though they both describe metric involute splines. The fundamental difference lies in the design approach. DIN 5480 is based on a reference diameter independent of the module, while ISO 4156 is based on the module series . This leads to different tooth profiles, dimensions, and tolerance systems. For pressure angles of 37.5° and 45°, ISO 4156 is the applicable standard, as DIN 5480 is limited to 30° pressure angles.
| Symbol | Meaning | Description | | :--- | :--- | :--- | | | Reference diameter | = m * z | | d B | Major diameter | Outer diameter of external spline | | d b | Minor diameter | Inner diameter of external spline | | d a | Root diameter | Internal spline minor diameter | | p | Circular pitch | = π * m | | α | Pressure angle | 30° or 37.5° |
DIN 5480 is the German standard for . Unlike parallel-sided splines (often covered by DIN 5464), involute splines have teeth with an involute profile—similar to gears.
Here is what each segment means:
Most technical guides, such as the Doppler Gear Decoder or the eAssistant Handbook , provide tables for standard sizes. Standard Sizes (Examples) Number of Teeth ( N30 x 2 N50 x 2 Design Considerations
You can use these dimensions to design and manufacture splines according to the DIN 5480 standard.
) are equal in standard profiles where no profile shift is applied). p=π×mp equals pi cross m Base Diameter ( ): din 5480 spline dimensions pdf
The major and minor diameters (tip diameters for external and internal splines) depend heavily on the specific fit type selected (e.g., flat root or fillet root). Approximates Internal Spline Minor Diameter ( di2d sub i 2 ): Approximates 3. DIN 5480 Nomenclature and Designation Codes
To understand the data inside a DIN 5480 dimensions PDF, you must know how the primary geometric values are derived. The system uses a module ( ) and the number of teeth ( ) to establish basic sizes. Given standard value (e.g., 1, 2, 5) Number of Teeth Given integer Reference Diameter Base Diameter Circular Pitch Tip Diameter Formulas (Vary by Fit):
DIN 5480 profiles are split into external splines (shafts) and internal splines (hubs). They feature specific tip and root diameter limits to ensure proper clearance during engagement. Shaft (External Spline) Dimensions : The maximum outside diameter of the shaft. Root Diameter ( df1d sub f 1 end-sub It is crucial to understand that , even
⚠️ Note: Free PDFs often contain summarized tables. For certified production or legal compliance, purchase the full standard from DIN.
db=d×cos(30∘)=d×0.866025d sub b equals d cross cosine open paren 30 raised to the composed with power close paren equals d cross 0.866025 External Spline (Shaft / "W") Nominal Sizes:
A typical spline callout looks like this: . W (Welle): Denotes a Shaft (External spline). N (Nabe): Denotes a Hub (Internal spline). 120: The Reference Diameter . 3: The Module ( 38: The Number of Teeth ( 8f: The Tolerance Class (defining the fit). Key Dimensional Differences This leads to different tooth profiles, dimensions, and
Before locking in a non-standard tooth count, check with your machine shop to ensure they have the appropriate hob or broach tool to avoid custom tooling surcharges.
The DIN 5480 standard is a series of technical specifications developed by the Deutsches Institut für Normung (DIN) that defines the geometry, dimensions, and tolerances of involute splines. Unlike many other standards that define splines directly by a module and number of teeth, DIN 5480 uses a unique and powerful concept: the reference diameter.