Hollow Motor Shaft

-- Steady & Reliable Manufacturer --

A hollow motor shaft has a continuous bore running through its center, offering two key advantages over a solid shaft: it is significantly lighter (typically 30–50% mass reduction), and it allows cables, pneumatic lines, laser beams, or coolant to pass through the motor axis — a feature essential in many automation and robotics designs.

Fenglan machines hollow shafts from seamless tube stock or from solid bar that is gun-drilled after OD turning. Both routes achieve the concentricity between bore and OD (typically ≤ 0.03 mm TIR) needed for balanced high-speed rotation. Wall thickness as thin as 3 mm is achievable on standard grades.

Specification

Outer Diameter	20 mm – 150 mm
Bore Diameter	8 mm – 120 mm (wall thickness ≥ 3 mm)
Length	50 mm – 1,500 mm
OD–Bore Concentricity	≤ 0.03 mm TIR (standard); ≤ 0.015 mm (precision)
OD Tolerance	h6 (bearing seats); h8 (general)
Bore Surface Finish	Ra 1.6 μm honed or reamed (standard); Ra 0.8 μm on request
Material	45# steel, 40Cr alloy steel, 304/316 SS, 6061-T6 Al
Manufacturing Method	Seamless tube + OD turning, or solid bar + gun-drill boring
Additional Features	External keyways, splines, threads, flanges compatible
MOQ	5 pcs; 1 pc prototype

Application

Hollow motor shafts are the standard choice in systems where through-bore access or weight reduction is a design priority:

Torque motors and direct-drive rotary stages — through-bore for cable, encoder wiring, or pneumatic lines
Robotic joint actuators — routing power and signal cables through the joint axis without external trunking
Spindle motors (machine tools) — pull-through drawbar mechanism for tool clamping
Hollow shaft encoders — shaft passes through the encoder body for direct-mount feedback
Lightweight drive systems — UAV motor shafts, racing machinery, weight-sensitive portable equipment
Laser and optical systems — co-axial beam delivery through the motor for laser cutting rotary axes

Advantage

Through-bore access — enables clean, protected cable/pipe routing through the motor axis, eliminating external cable drag chains
30–50% weight saving vs. equivalent solid shaft, directly reducing rotor inertia and improving dynamic response
Lower rotor inertia — critical for servo systems requiring high acceleration/deceleration rates
Precision concentricity — ≤ 0.03 mm OD–bore TIR ensures balanced rotation at high speed
Both manufacturing routes available — tube-based for standard sizes (faster lead time); gun-drilled for non-standard bores with maximum material integrity
Compatible with external features — keyways, splines, and flanges can be combined with the hollow bore in one machining run

Payment & Shipping

We accept T/T (bank transfer), L/C at sight, PayPal (samples), and Western Union. A 30% deposit is required to confirm production, with the balance paid before shipment.

Standard lead time is 7–15 business days for regular orders; prototype samples ship within 3–5 days. We ship worldwide via DHL, FedEx, UPS, sea freight (FCL/LCL), and air freight. FOB Changzhou and CIF terms are both available. All goods are packed in export-standard cartons with foam padding or wooden crates for heavy items. A commercial invoice, packing list, and COA are provided with every shipment. For large OEM orders, customized packaging and private-label options are available upon request.

Q: What is the minimum wall thickness for a hollow motor shaft?
A: Our standard minimum wall thickness is 3 mm for steel grades. For aluminum and larger diameters we can go to 2.5 mm. Walls thinner than this are possible but require engineering review for structural adequacy under the intended torque and bending loads.

Q: How do you ensure concentricity between the bore and outer diameter?
A: For tube-based shafts, we turn the OD in the same setup as the bore finishing to maintain concentricity. For gun-drilled parts, the bore is drilled after OD rough turning, and concentricity is verified on a bench V-block or CMM. Standard TIR is ≤ 0.03 mm; ≤ 0.015 mm is achievable for precision grades.

Q: Can you machine keyways or splines on the outside of a hollow shaft?
A: Yes. External features such as keyways, involute splines, and threads are machined on the hollow shaft OD using the same process as solid shafts. The hollow bore does not affect our ability to add these features.

Q: Is a hollow shaft weaker than a solid shaft of the same OD?
A: In bending and torsion, a hollow shaft with a thin wall is only marginally weaker than a solid shaft of the same OD, because most of the stress is carried by the outer material anyway. The significant mass reduction is achieved with minimal strength penalty — this is the same principle used in structural tubing.

Changzhou Fenglan New Materials Co., Ltd.

ABOUT US

Quality is Our Core Competitiveness

Changzhou Fenglan New Materials Co., Ltd.

Founded in 2010, As China Hollow Motor Shaft Manufacturers and Hollow Motor Shaft Company. we are dedicated to manufacturing precision parts for automotive, industrial, and electrical applications. Backed by advanced manufacturing and R&D, we provide high-quality products and trusted solutions to our clients. We provide a wide selection of components to meet diverse industry needs: Electric Shafts: Drive shafts, coil motor shafts, servo motor shafts, water pump motor shafts, industrial motor shafts, and magnetic levitation motor shafts. Hardware: Precision parts for medical equipment, water heater coils, plumbing fittings, and various gas springs. Our commitment is to support our customers with reliable performance and long-term value.

We look forward to working with you

With a strong R&D team, we are ready to take on challenges and bring creative ideas to the market.

Leave your message

Your email address will not be published. Required fields are marked *

Recommended LINS: CNC Machined Motor Shaft Stepped Motor Shaft Stainless Steel Motor Shaft CNC Turned Motor Shaft

Web Menu

Product Search

Language

Exit Menu