Focusing on the design, manufacturing processes, heat treatment techniques, and key quality control points for all types of standard and non-standard gears.
| Parameter | Specification |
| Spline Type | Triangular Spline / Serrated Spline |
| Spline Standard | DIN 5481, GB/T, or Custom |
| Number of Teeth | Z=10–40, Customizable |
| Shaft Diameter / Outside Diameter | Customizable |
A triangular spline shaft is a power transmission shaft with triangular spline teeth machined around its outer circumference. It normally works with a matching triangular internal spline sleeve to form a spline pair. Multiple tooth flanks share the transmitted torque, providing a reliable connection. Depending on the application, the shaft can be designed for fixed connections or axial positioning.
Compared with conventional keyed shafts, triangular spline shafts use multiple teeth to distribute the transmitted load. This gives them a compact structure, stable fit, and reliable connection, making them suitable for medium-low-speed, medium-load transmission systems and applications where installation space is limited.
Depending on the equipment and operating conditions, tooth count, tooth profile dimensions, shaft diameter, spline length, fit tolerances, material, and heat treatment can be customized. They are suitable for agricultural machinery, construction equipment, automotive components, gear reducers, and industrial transmission systems.
A triangular spline shaft mainly consists of the shaft body and spline section, with evenly distributed teeth around the outer circumference. The triangular tooth profile is designed according to the required spline specifications. Tooth count, tooth dimensions, shaft diameter, spline length, and fit tolerances can be controlled to match different internal spline sleeves and transmission requirements.
Compared with conventional keyed connections, triangular spline shafts distribute the transmitted load across multiple teeth. This helps reduce localized loading and provides a reliable shaft-to-hub connection within a compact radial space.
A triangular spline shaft normally forms a spline pair with a matching internal spline sleeve. Torque is transmitted through tooth flank contact, while proper tooth geometry and fit design help improve centering and load distribution, resulting in a more stable connection.
Depending on the mating structure and operating requirements, the tooth profile and fit tolerances can be adjusted to provide reliable torque transmission and consistent engagement.
Triangular spline shafts provide good torsional strength, connection rigidity, and positioning performance. They are suitable for medium-low-speed and medium-load transmission applications.
Proper control of tooth geometry, fit clearance, material selection, and heat treatment can improve spline flank wear resistance, fatigue performance, and long-term operating stability.
Triangular spline shafts offer a simple structure, mature manufacturing processes, reliable power transmission, and convenient assembly and disassembly. They are commonly used in agricultural machinery, construction equipment, automotive components, gear reducers, and industrial transmission systems.
Depending on the operating conditions, spline dimensions, fit tolerances, materials, and heat treatment can be customized to meet specific transmission and connection requirements.
| Parameter | Standard Mass-Production Model (General Service) | High-Precision Custom Model (Precision Transmission) |
| Core Transmission Specifications | ||
| Product Type | Triangular Spline Shaft | Precision triangular spline shaft; non-standard designs available |
| Spline Type | Triangular spline / serrated spline | Special tooth profiles and non-standard structures available |
| Spline Standard | Specified according to drawing and mating spline sleeve; DIN, GB, ISO, and other standards supported | Standard spline and non-standard precision designs supported |
| Number of Teeth | Z=10–40, customizable according to torque, shaft diameter, and structural requirements | Optimized for load, service life, and fit accuracy |
| Tooth Profile Parameters | Designed according to spline specification and mating requirements | Tooth profile optimization, flank modification, and precision fit available |
| Shaft Diameter / Outside Diameter | Designed according to transmission load and installation space | Optimized for load capacity, rigidity, and fit accuracy |
| Spline Length | Customized according to engagement length and mating structure | Optimized for load and positioning accuracy |
| Fit Type | Fixed or positioning connection | High-precision fixed and positioning fit |
| Fit & Accuracy Specifications | ||
| Centering Method | Determined according to the applicable standard and mating structure | Precision control of centering accuracy and fit tolerances |
| Accuracy Grade | Customized according to application and applicable standard | High-precision dimensional and fit control available |
| Tooth Profile Accuracy | Standard spline machining | Optimized tooth profile, tooth count, and key dimensional accuracy |
| Fit Accuracy | Standard fit control | Precision control of fit tolerances, concentricity, and clearance |
| Materials & Manufacturing Capabilities | ||
| Material Selection | 45 Steel, 40Cr, 42CrMo, stainless steel, and other materials | 42CrMo, 20CrMnTi, 20CrMo, and other high-performance alloy steels |
| Heat Treatment | Quenching and tempering, induction hardening | Carburizing and hardening, induction hardening, and other surface hardening treatments |
| Machining Processes | Gear milling, hobbing, shaping, and other processes | Precision milling, shaping, sizing, and finishing |
| Surface Treatment | Black oxide, phosphating, and corrosion protection | Precision corrosion protection and special surface treatments |
| Load & Application | ||
| Load & Positioning | Medium-load, fixed or positioning connections | Higher torque, high-precision, continuous-duty connections |
| Typical Applications | Agricultural machinery, construction machinery, general drives, and gear reducers | Automation equipment, machine tools, and precision transmission systems |
| Operating Conditions | Medium-low-speed, medium-load transmission | High-precision, high-reliability, and long-term operation |
| Remarks | The above are standard machining parameter ranges for our triangular spline shafts. Special sizes and non-standard structures can be custom-made according to your drawings or samples. For a quotation, please provide the spline standard, number of teeth, shaft diameter, spline length, material, accuracy requirements, and quantity. | |
High-quality blanks are forged and normalized to eliminate internal stress and stabilize material structure.
Turning, milling and hobbing/shaping are applied to form the target tooth profile with strict accuracy control.
Carburizing quenching or tempering processes to improve tooth surface hardness and core toughness.
Grinding of tooth flanks, bores and datum faces to correct deformation and enhance meshing precision.
Full-dimensional verification by gear measuring center and CMM to qualify products before release.
Professional anti-rust and protective packaging to keep products intact during storage and transit.
High-precision gear grinding delivers tooth surface roughness as low as Ra 0.4, with tight meshing, low vibration and noise for smoother equipment operation.
Premium materials matched with precise heat treatment ensure wear-resistant tooth surfaces and impact-resistant core, cutting maintenance and replacement costs.
Custom solutions for high-speed heavy load, corrosion resistance and food-grade scenarios, eliminating trial-and-error costs in product selection.
Scaled production supports tiered pricing for bulk orders with consistent quality; full-process control guarantees stable lead time and complete after-sales support.
Representative Grade: 45 Steel / C45
45 steel offers a good balance of strength, toughness, and machinability at a moderate cost. After quenching and tempering, it provides good overall mechanical properties. It is suitable for triangular spline shafts used in general machinery, agricultural equipment, and medium-load transmission applications.
Representative Grades: 40Cr, 42CrMo
40Cr and 42CrMo provide high strength, toughness, and fatigue resistance. Quenching and tempering or induction hardening can improve spline flank hardness and wear resistance. They are suitable for automotive transmissions, construction machinery, gear reducers, and medium- to high-load systems.
Representative Grades: 20CrMnTi, 20CrMo
20CrMnTi and 20CrMo develop a hard surface layer and tough core after carburizing and hardening. They provide good wear resistance, fatigue resistance, and impact strength, making them suitable for automotive transmissions, heavy-duty machinery, and spline shafts for continuous operation.
Representative Grade: 38CrMoAl
38CrMoAl can achieve high surface hardness, wear resistance, and dimensional stability after nitriding while retaining good core toughness. It is suitable for precision transmission systems, automation equipment, and triangular spline shafts requiring long-term dimensional stability.
Representative Grades: 304, 316, 420
Stainless steel offers good corrosion resistance and environmental durability. 304 and 316 are suitable for humid and corrosive environments, while 420 can achieve higher hardness and wear resistance after quenching and tempering. It is suitable for food, pharmaceutical, chemical, and other corrosion-sensitive transmission applications.
Representative Grades: QT450, QT500
Ductile iron combines good strength, wear resistance, and vibration damping. It is suitable for larger triangular spline shafts operating at low speeds and under medium loads. Typical applications include general machinery, agricultural equipment, and industrial transmission systems.
In tractors, harvesters, construction machinery, and other power equipment, triangular spline shafts are used in PTO shafts, transmission shafts, and actuating mechanisms for reliable torque transmission. Combined with materials such as 40Cr or 42CrMo and suitable heat treatment, they can support medium loads and long-term operation.
In automotive components and general mechanical transmission systems, triangular spline shafts connect gears, sleeves, and other rotating parts for torque transmission and axial positioning. Their compact design and easy assembly make them suitable for applications where connection reliability and convenient maintenance are important.
In gear reducers, transmission boxes, and industrial power transmission equipment, triangular spline shafts are used to connect input shafts, output shafts, and other transmission components. Proper control of spline dimensions, fit tolerances, and material selection helps improve shaft connection stability for continuous-duty and medium-load applications.
In automation equipment, machine tools, and precision mechanical transmission systems, triangular spline shafts are used where controlled fit clearance and positioning accuracy are required. Optimizing spline dimensions, machining accuracy, and heat treatment can improve operating stability and long-term service performance.
In hydraulic pumps, hydraulic motors, and power actuators, triangular spline shafts connect drive shafts with actuating components for reliable torque transmission. Appropriate material selection and heat treatment based on load and operating conditions can improve spline flank wear resistance and connection service life.
In industrial robots, automated actuators, and mobile equipment, triangular spline shafts connect drive shafts with gears, couplings, and other transmission components. Precise control of spline dimensions and fit tolerances helps meet requirements for repeatable motion, reliable positioning, and stable power transmission.
Inner VCI vacuum anti-rust process fully seals tooth flanks and critical machined surfaces, effectively resisting salt spray and moisture during ocean and air freight to keep precision gears corrosion-free throughout long-distance transit.
We select cost-effective logistics channels with stable transit time and controlled costs. Full logistics tracking is available with real-time status updates to ensure reliable and punctual delivery.
All products are covered by a 1-year warranty. Quality defects caused by non-human factors are fully guaranteed, removing your procurement concerns.
Our professional technical and after-sales team is always available to respond quickly to inquiries and after-sales needs, and efficiently resolve issues during installation and operation.
We support full-parameter OEM/ODM customization based on 2D/3D drawings or physical samples, including module, tooth profile, material and heat treatment specifications. You only need to provide core gear parameters, detailed drawings or physical samples to start the customization process.
You can send physical samples to us via international courier. Upon receipt, we will complete full-dimensional measurement and parameter verification, then arrange sample production after confirming the solution, ensuring the finished product fully matches the original in installation dimensions and transmission performance.
Prototype orders usually ship within 15–25 days, subject to heat treatment and grinding scheduling. Lead time for bulk orders will be confirmed after process finalization, with stable and well-managed production schedules.
We adopt a tiered pricing policy — the larger the order quantity, the more favorable the unit price. All orders follow the same production and quality inspection standards with strict accuracy control. Quality will never be compromised for larger order volumes.
We can include dimensional inspection reports, hardness test records and material certificates with each shipment. For high-precision key projects, professional inspection data from CMM and gear measuring centers is also available.
All products come with a 1-year warranty covering material defects and manufacturing quality issues under normal use. We also have a professional technical team to provide full-process consultation and selection support.
Spur gears feature a simple structure and no axial load, ideal for medium-low speed general transmission with higher cost-effectiveness. Helical gears run smoother with lower noise and higher load capacity, suitable for high-speed heavy-duty applications. We can recommend the optimal solution based on your actual requirements.
+86 184 3796 0706 
info@destinytrans.com 
