SJ-2B6603TK (Mitsubishi Electric)

SJ-2B6603TK is a Mitsubishi Electric SJ-B series built-in AC spindle motor, used in medium-to-heavy duty CNC machining centers. It belongs to the SJ-2B 6600-series, which is designed for high torque, stable low-speed cutting, and industrial-grade machining loads.

It sits in the same family as SJ-2B6602TK but uses a different winding/configuration (03 variant) that changes its torque–speed characteristics.

🔧 Verified specifications (official Mitsubishi data)

From Mitsubishi SJ-B series specification manual:
(Mitsubishi Electric CNC Spindle Motor Table)

Parameter	Value
Continuous rated output	15 kW (low-speed coil) / 15 kW (high-speed coil)
Short-time rated output	22 kW (30 min rating)
Acceleration/deceleration output	22 kW (standard)
Actual accel/decel output	26.4 kW
Base speed	600 rpm / 1200 rpm (coil dependent)
Maximum speed	1500 rpm / 6000 rpm
Continuous torque	239 N·m / 119 N·m
Short-time torque	350 N·m / 175 N·m
Rotor inertia	0.173 kg·m²
Frame size	160–295 mm class
Cooling	Liquid / oil jacket cooling
Drive unit	MDS-D2-SP-320

🔧 Model code breakdown

Code part	Meaning
SJ	Mitsubishi spindle motor family
2B	SJ-B built-in spindle series
6603	15 kW class, high-torque winding variant
TK	terminal / connector type

So:

SJ-2B6603TK = 15 kW high-torque built-in spindle motor optimized for heavy-duty machining

⚙️ How SJ-2B6603TK differs from 6602TK

Feature	6602TK	6603TK
Power class	11 kW	15 kW class behavior
Torque tuning	Balanced	Higher torque / heavier cutting focus
Inertia	0.133 kg·m²	0.173 kg·m² (higher)
Application	Medium-heavy machining	Heavy-duty machining

👉 In simple terms:

6603TK is the stronger, heavier-cutting variant in the 6600-series.

🏭 Typical applications

SJ-2B6603TK is used in:

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

It is selected when machines need:

🧱 high cutting force
⚖️ strong low-speed torque stability
🎯 continuous heavy-duty machining
🔧 rigid spindle performance under load

⚖️ 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-2B6603TK is a 15 kW-class built-in CNC spindle motor designed for heavy-duty machining, optimized for high torque and stable cutting performance under industrial loads.

Mitsubishi M80 Built-IN Spindle Motor SJ-2B6603TK

Description