Description
G Series PTO Drive Shaft – German-Standard Round Tube for Precision Power Transfer
The G Series PTO drive shaft is built around the German-standard round tube profile — the same geometry specified by leading European driveline engineers. Round tubes provide the most concentric and balanced rotating assembly of any PTO shaft design, minimizing vibration and maximizing bearing life in both the shaft and the driven implement’s gearbox. Ten models spanning G2 to G50 deliver torques from 450 Nm to 3,700 Nm, covering everything from mid-range disc mowers to large-scale forage processing equipment.
Preferred industries: Precision agriculture, dairy farming, grain harvesting, biomass processing, municipal works, and industrial power take-off applications.
At a glance: Precision-ground round tubes · German DIN standard tolerances · Forged yokes with induction-hardened splines · Sealed heavy-duty cross kits · Complete CE safety shield assembly.
G Series Full Specification Table
| Model | Cross (mm) | Outer Tube | 540 RPM Kw | 540 RPM Pk | 540 RPM Nm | 1000 RPM Kw | 1000 RPM Pk | 1000 RPM Nm | MP (NM) |
|---|---|---|---|---|---|---|---|---|---|
| G2 | 23.8×61.3 | 50×2.5 G35-18 | 15 | 21 | 270 | 23 | 31 | 220 | 450 |
| G4 | 27×74.6 | 50×2.5 G35-18 | 26 | 35 | 460 | 40 | 55 | 380 | 780 |
| G5 | 30.2×80 | — | 35 | 47 | 620 | 54 | 74 | 520 | 1050 |
| G6 | 30.2×92 | 60×3 G40-14 | 47 | 64 | 830 | 74 | 100 | 710 | 1450 |
| G7 | 30.2×106.5 | — | 55 | 75 | 970 | 87 | 118 | 830 | 1800 |
| G8 | 35×106.5 | 65×3.5 G45-16 | 70 | 95 | 1240 | 110 | 150 | 1050 | 2250 |
| G38 | 38×105.6 | 65×3.5 G45-16 | 78 | 105 | 1380 | 123 | 166 | 1175 | 2500 |
| G42 | 42×104.5 | — | 79 | 107 | 1400 | 122 | 166 | 1175 | 2500 |
| G50 | 50×118 | 75×4 G55-20 | 119 | 162 | 2095 | 182 | 248 | 1740 | 3700 |
How Round-Tube PTO Shafts Achieve Superior Balance
Unlike profiled tubes (triangular, lemon, star) that rely on geometric interlocking for torque transfer, the G Series round tube transmits torque via a precision keyway or spline machined along the inner bore. The advantage is perfect concentricity — round tubes can be ground to surface finishes below Ra 1.6 µm, ensuring the rotating assembly is as balanced as a machined crankshaft. This balance translates directly into reduced vibration at the tractor PTO bearing, lower noise at the operator’s station, and extended gearbox input-shaft bearing life on the implement.
Complete assembly components: Tractor-end yoke (push pin or quick release) · Outer round tube with welded yoke · Inner round tube with welded yoke · Implement-end yoke · Precision cross kits with quad-lip seals · Safety shield assembly (inner & outer guard cones and tubes) · Safety chains · Spring pin hardware.
Advantages That Define the G Series
Precision Ground Tubes
Outer diameter ground to h8 tolerance and inner bore to H8 provides a sliding fit with minimal radial play — essential for high-speed 1,000 RPM applications.
Vibration-Free Operation
Round geometry eliminates the inherent mass imbalance of profiled tubes, resulting in less than 0.5 mm/s vibration at rated RPM on properly aligned installations.
European DIN Standard
Tube dimensions follow German DIN standards (G35, G40, G45, G55 series), ensuring seamless interchangeability with European OEM equipment.
Quad-Lip Sealed Crosses
Cross kits feature four-lip contact seals that provide double the sealing area of standard single-lip designs, extending service life in wet or dusty environments.
Versatile Torque Range
From the compact G2 at 450 Nm to the robust G50 at 3,700 Nm, the G Series covers virtually every PTO-driven machine in a modern fleet.
Construction Details & Material Grades
G Series round tubes are manufactured from seamless E355+SR (EN 10305-1) precision steel tubing, which is then ground on the OD and honed on the ID to achieve the tight clearance fit required for smooth telescoping under load. The keyway is broached to DIN 6885 profile. Yokes are produced from 42CrMo4 (AISI 4140) drop forgings, normalized at 860 °C, quenched, and tempered to achieve a tensile strength of 1,000 MPa. Bearing bores are induction-hardened to HRC 60. Cross kits use 100Cr6 (AISI 52100) bearing steel with a surface hardness of HRC 62, ensuring maximum rolling contact fatigue resistance. All zinc plating meets ISO 4042 Class A requirements with a minimum 12 µm coating thickness for outdoor corrosion resistance.
Application Guide – Where the G Series Excels
| Equipment | Model Range | Application Insight |
|---|---|---|
| High-Speed Disc Mower | G4 – G6 | Mowers running at 1,000 RPM demand the balance and low vibration that only a round-tube shaft provides. |
| Precision Planter | G2 – G5 | Seed metering accuracy depends on smooth, jerk-free PTO input; G Series round tubes deliver exactly that. |
| Center-Pivot Irrigator Drive | G5 – G7 | Long continuous run times at moderate torque; ground tubes resist wear for thousands of operating hours. |
| Combine Header Drive | G6 – G38 | Cutting header demands instant torque response and minimal driveline backlash — hallmarks of the G Series. |
| Slurry Tanker Pump | G38 – G50 | Pumping viscous slurry at high flow rates requires sustained torque; the G50 handles peak loads effortlessly. |
| Industrial Generator Drive | G7 – G42 | PTO-driven generators need the lowest possible vibration to maintain stable electrical output frequency. |
Selecting the Ideal G Series Model
- Confirm the implement’s German tube standard: Check the implement manual for the existing tube designation (e.g., G35-18, G40-14, G45-16, G55-20). Match this to the G Series spec table.
- Verify torque demand: Cross-reference the implement’s required input power (kW) and PTO speed with the G Series torque columns.
- Measure installation geometry: Record minimum and maximum centre-to-centre distances. Ensure adequate telescopic overlap (minimum one-third of tube engagement length).
- Identify connection types: Specify spline profile and yoke style for both tractor and implement ends. Common options include 1-3/8" 6-spline, 1-3/8" 21-spline, 1-3/4" 6-spline, and 1-3/4" 20-spline.
- Assess speed sensitivity: If the driven implement is speed-sensitive (generators, precision planters), the G Series round tube is the preferred choice over any profiled alternative.
- Plan maintenance access: Ensure grease fittings on cross kits are accessible after installation for routine lubrication.
For complex multi-shaft or custom-length requirements, contact our technical department directly.
Brand Replacement Compatibility
The G Series is engineered as a dimensional equivalent for round-tube PTO shafts from these respected manufacturers:
- Walterscheid – GKN Walterscheid round-tube series
- Bondioli & Pavesi – Round profile assemblies
- Elbe Gelenkwellen – German-specification cardan shafts
- SKF (Couplings Division) – Round tube PTO products
- Spicer – European agricultural driveshaft range
The brands listed above are trademarks of their respective owners. References are made exclusively to communicate product compatibility and are not intended to suggest any partnership or endorsement.
Source individual G Series components — round tubes, yokes, cross kits, and safety shields — through our parts catalog.
Quality Standards & Service Guarantee
ISO 9001:2015
Full quality system certification with annual third-party audits covering forging, machining, heat treatment, and assembly.
CE Declaration
Each shaft carries a Declaration of Conformity per EU Machinery Directive 2006/42/EC, shipped with the product.
18-Month Warranty
Extended warranty reflects the premium materials and precision manufacturing of the G Series. Hassle-free claim processing.
G Series Frequently Asked Questions
What does the “G” designation mean in German tube standards?
The “G” prefix denotes the German (Gelenkwelle) tube standard. The number following (e.g., G35, G40, G55) indicates the nominal inner diameter of the outer tube in millimeters. The second number specifies wall thickness class.
Is the G Series only for European equipment?
While the G Series follows German DIN tube standards commonly found on European implements, it is equally suitable for any application requiring a round-tube PTO shaft — including North American, Australian, and Asian equipment that specifies round tube connections.
How does the keyway transmit torque in a round tube?
A longitudinal keyway broached into both the inner and outer tubes, along with a matching key, locks the tubes rotationally while allowing free axial sliding. This method provides a large shear area for torque transfer with zero backlash.
Can G Series shafts be used at 1,000 RPM continuously?
Yes. The precision-ground round tubes and dynamically balanced assembly make the G Series the preferred choice for sustained 1,000 RPM operation, producing less heat and vibration than profiled alternatives.
What is the lead time for custom G Series orders?
Standard models ship from stock within 3–5 business days. Custom tube lengths or non-standard yoke combinations typically require 15–20 business days.
How do I maintain the round tube sliding fit over time?
Apply a thin coat of lithium EP2 grease to the inner tube surface at every lubrication interval. Avoid using anti-seize compounds, which can attract abrasive dust. If the tubes develop excessive play (> 0.5 mm), replace as a matched set.
Global Field Reports – G Series in Action
“We run G6 shafts on our disc mowers at 1,000 RPM for 10 hours a day during the grass season. The vibration level is noticeably lower than the triangular shafts they replaced — our operators noticed the difference immediately.” — Haymaking contractor
“As a European dealer, dimensional compatibility with Walterscheid round-tube specs is critical. The G Series matches every measurement we checked — tube OD, bore, keyway width — within tolerance.” — Driveline specialist, farm equipment supplier
“G38 shafts on our slurry tankers. Pumping thick dairy effluent puts enormous sustained torque on the driveline. Two seasons in, and the cross kits are still perfectly smooth.” — Dairy farm engineer
“We specified G4 shafts for our precision vegetable planters. The smooth round-tube rotation translates to more consistent seed spacing — we measured a 12 percent improvement in planting uniformity.” — Horticultural operations manager
“Importing G50 shafts for our biomass chipping operation. The heavy-duty cross kits and German-standard tubes handle eucalyptus logs without complaint. We’ve halved our driveline maintenance budget.” — Biomass energy project coordinator
Let’s Build a Partnership
The G Series represents our premium PTO shaft offering, engineered for customers who accept no compromise on precision and durability. Whether you are an OEM integrator, a national distributor, or a single-farm buyer, we provide the same level of technical support and product quality. Reach out today to discuss pricing, lead times, and custom configurations.
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