SJ-BG090D/300-03☐ (Mitsubishi Electric)

SJ-BG090D/300-03☐ is a Mitsubishi Electric SJ-BG series built-in AC spindle motor, intended for ultra-high-speed precision machining applications where the motor is integrated directly into the spindle assembly.

This model belongs to the 90 mm-class BG built-in spindle family, optimized for:

• high rotational speed
• compact spindle construction
• low vibration
• high precision contour machining

🔧 Model code breakdown

So:

SJ-BG090D/300-03☐ = 90 mm built-in spindle motor for ~30,000 rpm precision machining with D-type configuration

🔧 Typical specifications (BG090D/300 class)

Based on Mitsubishi SJ-BG spindle family data and configuration patterns: (mitsubishielectric.com)

⚙️ What “090D” means

Within the BG family:

The D-type version is generally associated with:

• improved structural stiffness
• enhanced thermal behavior
• better stability during long high-speed operation

⚙️ What “☐” means

The square placeholder:

☐ = optional OEM/machine-builder configuration code

It may define:

• encoder type
• connector orientation
• cooling arrangement
• bearing preload
• balancing grade
• custom machine option

🏭 Typical applications

SJ-BG090D/300-03☐ is commonly used in:

• high-speed mold & die machining
• graphite machining
• precision milling
• PCB drilling
• compact high-speed machining centers
• precision finishing operations

It is selected when machines need:

• ⚡ very high spindle speed
• 🎯 precision contour accuracy
• 📉 low vibration
• 🧱 excellent rigidity in compact spindle form

⚖️ Position in Mitsubishi spindle lineup

🧠 Simple explanation

SJ-BG090D/300-03☐ is a 30,000 rpm-class built-in spindle motor designed for compact, ultra-high-speed precision machining with enhanced rigidity and thermal stability.