SJ-2B6605TK (Mitsubishi Electric)

SJ-2B6605TK is a Mitsubishi Electric SJ-B series built-in AC spindle motor, used in medium-to-heavy duty CNC machining centers. It is part of the SJ-2B 6600/6605 family, which is designed for high torque, stable cutting, and robust industrial machining performance.

It sits in the same power family as SJ-2B6602TK but with a different winding / speed-torque configuration (05 variant).

🔧 Verified specifications (official Mitsubishi data)

From Mitsubishi SJ-B series specification manual:

Parameter	Value
Continuous rated output	11 kW
Short-time rated output	15 kW (30 min rating)
Acceleration/deceleration output	15 kW (low-speed coil) / 18 kW (high-speed coil)
Actual accel/decel output	18 kW
Base speed	440 rpm / 1000 rpm (coil dependent)
Maximum speed	1500 rpm / 6000 rpm
Continuous torque	239 N·m / 105 N·m
Short-time torque	326 N·m / 143 N·m
Rotor inertia	0.173 kg·m²
Stator OD	Φ254.5 mm class
Rotor inner diameter	Φ110 mm
Cooling	Liquid/oil jacket cooling
Motor mass	~63 kg (stator), ~33 kg (rotor)

🔧 Model code breakdown

Code part	Meaning
SJ	Mitsubishi spindle motor family
2B	SJ-B built-in spindle series
6605	11 kW class, high-torque winding variant
TK	terminal / connector type

So:

SJ-2B6605TK = 11 kW high-torque built-in spindle motor optimized for heavy machining

⚙️ How SJ-2B6605TK differs from 6602TK

Both are in the same 11 kW class, but:

Feature	6602TK	6605TK
Power class	11 kW	11 kW
Torque tuning	Balanced high torque	Higher torque / heavier cutting bias
Speed range	Higher speed capability	Lower speed, stronger cutting force
Rotor inertia	0.133 kg·m²	0.173 kg·m² (higher)

👉 In simple terms:

6605TK is the “heavier cutting / stronger torque” version of the 6600-series.

🏭 Typical applications

SJ-2B6605TK is used in:

vertical machining centers (VMCs)
heavy milling machines
steel and cast iron machining
boring and drilling operations
industrial production CNC systems

It is chosen when machines need:

🧱 very high cutting torque
⚖️ strong low-speed stability
🎯 heavy-duty continuous machining
🔧 robust industrial reliability

⚖️ Position in Mitsubishi spindle lineup

Series	Role
SJ-2B	compact built-in spindle motors (older generation)
SJ-BG	modern high-speed integrated spindles
SJ-DG	high-torque cutting spindles
SJ-DL	external high-speed spindle motors

🧠 Simple explanation

SJ-2B6605TK is an 11 kW built-in CNC spindle motor designed for heavy-duty machining, offering very high torque and strong cutting performance, especially at low to medium spindle speeds.

Mitsubishi M80 Built-IN Spindle Motor SJ-2B6605TK

Description