Replacing a hydraulic pump or motor and need the shaft to fit the coupling or sleeve you already have? The spline must be exactly the same: same standard, same number of teeth and same pitch. This guide explains how SAE, DIN 5480 and DIN 5482 splines are written in catalogues and how to recognise them on the part.
The three families you will meet most
| SAE (inch) | DIN 5480 (metric) | DIN 5482 (metric) | |
|---|---|---|---|
| Where it is used | Pumps and motors with SAE mounting flange | European piston pumps and motors | European gear pumps and gearboxes |
| How it is written | Size letter, teeth and pitch: "SAE B 13T 16/32 DP" | W (shaft) or N (hub), diameter, module, teeth, tolerance: "W30x2x14x9g" | B (shaft) or A (hub) and two numbers in mm: "B17x14" |
| Profile | 30° involute, flat root, side fit | Involute | Involute |
An SAE spline and a DIN spline do not fit each other, even when the diameter looks the same: one is in inches and diametral pitch, the other in millimetres and module.
SAE splines (SAE J744 and SAE J498 / ANSI B92.1)
The letter (A, B, C, D) is the flange and shaft size of SAE J744. The number of teeth (T) and the diametral pitch (DP, for example 16/32) identify the spline.
| Size | Teeth | Diametral pitch |
|---|---|---|
| SAE A | 9 | 16/32 DP |
| SAE A (variant) | 11 | 16/32 DP |
| SAE B | 13 | 16/32 DP |
| SAE B-B | 15 | (see manufacturer's data sheet) |
| SAE C | 14 | 12/24 DP |
| SAE C-C | 17 | 12/24 DP |
| SAE D | 13 | 8/16 DP |
Indicative information. Check the marking on the part or the manufacturer's data sheet.
The same sizes also exist as keyed shafts, with the diameter in inches: B-B 1" (25.4 mm), C 1 1/4" (31.75 mm), C-C 1 1/2" (38.1 mm), D 1 3/4" (44.45 mm).
Indicative information. Check the marking on the part or the manufacturer's data sheet.
DIN 5480 splines
Example: W30x2x14x9g. W means shaft (male) and N means hub (female); 30 is the reference diameter in mm; 2 is the module; 14 is the number of teeth; 9g is the tolerance.
Sizes found in piston pump and motor catalogues:
| Designation | Diameter (mm) | Module | Teeth |
|---|---|---|---|
| W18x1.25x13 | 18 | 1.25 | 13 |
| W20x1.25x14 | 20 | 1.25 | 14 |
| W25x1.25x18 | 25 | 1.25 | 18 |
| W30x2x14 | 30 | 2 | 14 |
| W35x2x16 | 35 | 2 | 16 |
| W40x2x18 | 40 | 2 | 18 |
| W45x2x21 | 45 | 2 | 21 |
| W50x2x24 | 50 | 2 | 24 |
Indicative information. Check the marking on the part or the manufacturer's data sheet.
Large equipment uses bigger sizes, such as N120x3 or N150x5 on hubs.
DIN 5482 splines
Example: B17x14. B means shaft (male) and A means hub (female); the two numbers, in millimetres, identify the spline size. It is the most common spline on European group 1 and 2 gear pumps: for example B17x14 with 9 teeth, and B22x19 or B28x25 on larger sizes.
In catalogues the same pair of numbers appears with A on the hub and B on the shaft: an A40x36 hub takes a B40x36 shaft.
Tool: Identify the shaft of a pump or motor, step by step.
How to identify the spline on the part
- Look for the part number. The nameplate or the pump code often already states the shaft (for example "04" = SAE B 13 teeth on Casappa Polaris pumps). With the code, the manufacturer's data sheet gives the right shaft.
- Count the teeth. Mark one tooth with paint and count round.
- Measure the outside diameter of the spline with a caliper.
- Inches or millimetres? With the number of teeth and the diameter, compare with the tables above. If the diameter comes out as a round inch value (7/8", 1", 1 1/4"), it is most likely SAE; if it is a round millimetre value (17, 25, 30), it is most likely DIN.
- Check the flange. An SAE B shaft normally comes with an SAE B flange; a DIN shaft with a European or German flange.
Can't identify the shaft? Send us a photo of the shaft and the flange, with the number of teeth and the measured diameter. The Hidro Orfão technical team will help you find the right gear pump, motor or splined sleeve.
See also
Sources
- Parker Hannifin, F11/F12 Hydraulic Pump & Motor (MSG30-8249/UK, 2025).
- Casappa, Gear products (Polaris, Kappa, Plata).
- Dinamic Oil, Energy gearbox catalogue.
- Sauer-Danfoss, Gear pumps and motors (520L0557).
- Parker / Denison, P1 axial piston pumps.