Spline Shaft
Product Overview
Yubao Transmission Technology employs CNC gear hobbing, shaping, and thread rolling processes for spline manufacturing. We produce both rectangular splines (GB/T 1144) and involute splines (GB/T 3478, ISO 4156), with spline accuracy reaching Grade 7 (ISO 6H/7H), module range 0.5–3.0mm, and tooth count range 3–100. Combined with precision grinding, spline tooth surface roughness is controlled to Ra≤1.6μm and coaxiality ≤0.03mm, ensuring precise fit with mating sleeves and quiet operation.
Technical Parameters
Basic Parameters (Shaft Universal)
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Outer Diameter |
D |
mm |
21–350 |
h6–h9 |
Spline pitch diameter |
| Total Length |
L |
mm |
≤1500 |
±0.05 |
Including effective spline length |
| Straightness |
— |
mm |
0.01 |
≤ |
Generatrix straightness |
| Cylindricity |
— |
mm |
0.005 |
≤ |
Shaft body outer diameter |
| Radial Runout |
TIR |
mm |
0.008 |
≤ |
Between centers |
| Surface Roughness (Body) |
Ra |
μm |
0.2–0.8 |
≤ |
Ground areas |
| Surface Hardness |
HRC/HV |
— |
55–62 |
— |
Post-heat treatment |
| Material Grade |
— |
— |
Customized |
— |
Common: 20CrMnTi, 40Cr, 16MnCr5 |
| Heat Treatment |
— |
— |
Tempering/Carburizing/Nitriding |
— |
Determined by operating conditions |
| Center Hole Spec |
— |
— |
1.0–12.5 |
— |
Type A/B/C |
Spline-Specific Parameters
| Parameter |
Symbol |
Unit |
Value/Range |
Tolerance |
Notes |
| Spline Module |
m |
mm |
0.5–3.0 |
— |
Common: 0.5, 1.0, 1.5, 2.0 |
| Number of Teeth |
z |
— |
3–100 |
— |
Common: 6, 8, 10 teeth |
| Pressure Angle |
α |
° |
20°/30°/45° |
— |
Typically 30°, 45° |
| Spline Accuracy |
— |
Grade |
7 |
— |
Achievable: ISO 6H/7H |
| Spline Type |
— |
— |
Rectangular/Involute |
— |
Per customer drawing or standard |
| Effective Spline Length |
Ls |
mm |
Customized |
±0.05 |
Working engagement length |
| Coaxiality |
— |
mm |
0.03 |
≤ |
Spline to outer diameter |
| Tooth Surface Roughness |
Ra |
μm |
1.6 |
≤ |
Spline tooth surface requirement |
Machining Capabilities
| Process |
Equipment |
Range |
Accuracy Achieved |
| Spline Rolling |
Thread Rolling Machine (Xingchen ZPA 20–25T) |
Module 0.5–3mm |
Grade 7 accuracy |
| Spline Hobbing |
CNC Hobbing Machine (Ningjiang YK3610V) |
Module 0.5–8mm |
DIN Grade 7 |
| Spline Shaping |
Changji YKS5132 Shaper |
Outer diameter ≤320mm |
Internal splines/special structures |
| Precision Grinding |
Cylindrical/Centerless Grinder |
Length ≤1500mm |
Ra≤0.4μm |
| Heat Treatment |
Carburizing/Induction Hardening |
Case depth 0.5–1.5mm |
Tooth surface HRC 58–62 |
| Inspection |
VICI Vision/Gleason 300GMS |
Full automatic parameter inspection |
100% verification |
Spline Type Description
Rectangular Spline
- Features: Simple processing, selectable centering method (outer diameter, inner diameter, or tooth side centering)
- Applications: General mechanical transmission, medium load conditions
- Standards: GB/T 1144, ISO 14
Involute Spline
- Features: Involute tooth profile, high strength, automatic centering, adjustable fit clearance
- Applications: High-speed, high-torque applications requiring automatic centering
- Standards: GB/T 3478, ISO 4156, DIN 5480
Product Features
- High Torque Capacity: Multiple teeth engage simultaneously with large contact area, 3–5× higher capacity than single-key connections
- Precision Centering: Automatic centering characteristics with coaxiality ≤0.03mm, minimal runout during operation
- Wear Resistant: Carburized and hardened tooth surfaces at HRC 58–62 ensure long wear life
- Low Noise: Precision machined tooth profiles with controlled fit clearance for quiet transmission
- Customizable: Module, tooth count, pressure angle, and spline length can all be flexibly designed per customer requirements
Typical Applications
| Application Sector |
Specific Use |
Spline Specification Example |
| Construction Machinery |
Forklift hydraulic pump drive shaft |
Module 2.0mm, 8 teeth, rectangular |
| Automotive |
Transmission input/output shaft |
Module 1.5mm, involute spline |
| Industrial Reducers |
Reducer input shaft core |
Module 1.0–2.5mm, 6–10 teeth |
| Aerospace |
Actuator transmission shaft |
High-precision involute spline, Grade 6H |
| Agricultural Machinery |
Power take-off (PTO) shaft |
Module 2.0–3.0mm, high torque |
