Slim 90° Right Angle Head (DK90-BT50 ER Mini Nut Series)

Key Technical Features and Material Standards

• Slim Mini Nut Design: Features low-profile M-type mini collet nuts (ER11M, ER16M, ER20M, ER25M) without external hex protrusions. This reduces the nose swing clearance diameter down to D50 mm, allowing deep entry into narrow slots and internal bores where standard angle heads collide.
• Heavy-Wall QT500-7 Ductile Iron Housing: Cast from premium QT500-7 Ductile Iron and subjected to artificial aging and stress-relief heat treatment. The monoblock body provides high dynamic rigidity and vibration damping required for extended gage lengths up to 300 mm.
• Gleason Precision Ground Bevel Gears: Manufactured from 20CrMnTi Alloy Steel, gas-carburized and quenched to HRC 58-62, and ground to ISO Grade 4 precision on Gleason CNC grinders. Ensures gear transmission backlash ≤ 15 arcmin and running noise ≤ 70 dB under full operational load.
• Preloaded High-Capacity Bearings: Supported by preloaded, high-precision P4 class angular contact ball bearings (NSK/FAG) arranged to absorb axial thrust and radial cutting loads during deep-reach milling.

2D/3D Technical Drawings and CAD Download Center

Technical Specifications

Model	Input Shank	Spindle Output	Gage Length (L)	Max. Speed	Gear Ratio	Passing Dia. (D)	Clamping Range	Tapping Capacity	Max. Torque	Net Weight	Stock Status
DK90-BT50-ER11M-60	BT50	ER11M	60 mm	6,000 RPM	1:1	D55 mm	Ø1.0 – Ø7.0 mm	M5 – M6	8.8 Nm	11.201 kg	Always in Stock
DK90-BT50-ER11M-100	BT50	ER11M	100 mm	6,800 RPM	1:1	D55 mm	Ø1.0 – Ø7.0 mm	M5 – M6	8.8 Nm	11.528 kg	Always in Stock
DK90-BT50-ER11M-140	BT50	ER11M	140 mm	6,000 RPM	1:1	D55 mm	Ø1.0 – Ø7.0 mm	M5 – M6	8.8 Nm	11.869 kg	Always in Stock
DK90-BT50-ER11M-210	BT50	ER11M	210 mm	6,000 RPM	1:1	D55 mm	Ø1.0 – Ø7.0 mm	M5 – M6	8.8 Nm	12.412 kg	Always in Stock
DK90-BT50-ER11M-300	BT50	ER11M	300 mm	6,000 RPM	1:1	D50 mm	Ø1.0 – Ø7.0 mm	Thread Milling	10.8 Nm	14.200 kg	Always in Stock
DK90-BT50-ER16M-100	BT50	ER16M	100 mm	8,000 RPM	1:1	D77 mm	Ø1.0 – Ø10.0 mm	M5 – M8	18.0 Nm	12.231 kg	Always in Stock
DK90-BT50-ER16M-170	BT50	ER16M	170 mm	8,000 RPM	1:1	D77 mm	Ø1.0 – Ø10.0 mm	M5 – M8	18.0 Nm	13.152 kg	Always in Stock
DK90-BT50-ER20M-100	BT50	ER20M	100 mm	6,000 RPM	1:1	D85 mm	Ø1.0 – Ø13.0 mm	M5 – M10	30.0 Nm	3.500 kg	Always in Stock
DK90-BT50-ER20M-150	BT50	ER20M	150 mm	6,000 RPM	1:1	D85 mm	Ø1.0 – Ø13.0 mm	M5 – M10	30.0 Nm	3.500 kg	Always in Stock
DK90-BT50-ER20M-180	BT50	ER20M	180 mm	6,000 RPM	1:1	D85 mm	Ø1.0 – Ø13.0 mm	M5 – M10	30.0 Nm	14.500 kg	Always in Stock
DK90-BT50-ER25M-100	BT50	ER25M	100 mm	6,800 RPM	1:1	D110 mm	Ø1.0 – Ø16.0 mm	M6 – M14	46.0 Nm	12.232 kg	Always in Stock
DK90-BT50-ER25M-170	BT50	ER25M	170 mm	6,800 RPM	1:1	D110 mm	Ø1.0 – Ø16.0 mm	M6 – M14	46.0 Nm	15.600 kg	Always in Stock

Quality Assurance and Testing Standards

Before dispatch, every DK90-BT50 ER Mini Nut series angle head undergoes a 100% Quality Inspection Protocol:

• Static and Dynamic Runout Test: Spindle taper runout is checked with a high-precision dial indicator, held to ≤ 0.005 mm at the spindle nose and ≤ 0.015 mm at 4D distance.
• 60-Minute Continuous Run-In: Tested continuously at full rated operational speed for 60 minutes. Housing temperature rise must remain ≤ 25°C above ambient temperature.
• Anti-Backlash Calibration: Verified with angular encoders to confirm transmission backlash remains ≤ 15 arcminutes under rated load.

Target Industries and Industrial Applications

• Deep Mold and Die Cavities: Machining internal sidewalls, slider tracks, and angled ejector pin channels in large forged steel mold blocks where standard nuts cause tool clearance collisions.
• Heavy Machinery and Pump Housings: Finishing lateral internal features, valve pockets, and deep seal grooves inside large cast iron and steel housings.
• Aerospace and Defense Structural Parts: Deep-pocket side milling and thread milling on large structural frames made of aerospace-grade aluminum or titanium forgings.

CNC Machine Compatibility

Optimized for large Vertical Machining Centers (VMC), Horizontal Machining Centers (HMC), and Gantry Milling Machines. Compatible spindle shanks include:

• Spindle Standards: BT50 / BBT50 (Double Contact) / SK50 / CAT50 / HSK100A.
• Typical Machine Brands: Compatible with Mazak, Haas, Okuma, Doosan / DN Solutions, Makino, and JTEKT / Toyoda machine tools.

B2B Industrial Packing and Shipping Standards

• Anti-Rust Protection: Coated with heavy-duty anti-rust oil and vacuum-sealed in a high-barrier VCI (Vapor Corrosion Inhibitor) bag accompanied by industrial desiccant packs.
• Shock Absorption: Cradled inside custom-contoured, high-density polyurethane protective foam inserts to isolate the BT50 taper and long housing from transport shock.
• Export Outer Casing: Due to the heavy unit weight (up to 15.600 kg), each unit is packed in an ISPM 15-compliant, Fumigation-Free Plywood Wooden Case with reinforced metal edge locks.
• HS Code: 8466.10.10.00 or 8466.30.00.90.
• Lead Time: Standard models are shipped within 5-7 working days. Custom positioning blocks are shipped within 15-20 working days.
• Shipment Ports: Shanghai / Ningbo / Tianjin Port, China.
• Incoterms Supported: FOB, CIF, EXW, FCA, DDU, DDP.
• Express Delivery: Shipped via international air freight or ocean LCL/FCL containers depending on weight requirements.

Technical Setup and Stop Block Alignment Guide

codeText

       ┌──────────────────────────────────────┐
       │     MACHINE TOOL SPINDLE FACE        │
       └──────────────────┬───────────────────┘
                          │ (Spindle Centerline)
                          │ 
                          ▼◄──────  G  ──────►[STOP BLOCK]
                       ┌─────┐                    │
                       │Taper│                    │ (Locking Bore)
                       └─────┘                    ▼
                          │               ┌───────────────┐
                     ┌────┴────┐          │ Positioning   │
                     │  Body   ├──────────┤ Pin (D18/D20) │
                     │  Casing │          └───────────────┘
                     └─────────┘

1. Stop Block Mounting: Securely bolt the heavy-duty stop block to the front face of the VMC or HMC machine spindle.
2. Verify Center Distance (G-Dimension): Confirm that the center-to-center distance between the machine spindle and positioning pin socket matches your ordered G-Distance (commonly 80mm, 110mm, or 135mm on BT50 machines).
3. Indicate Side Runout: Chuck a ground test arbor into the ER mini nut collet. Sweeping a dial indicator along the arbor horizontally, adjust the stop block’s locking bolts until parallelism is aligned within 0.015 mm per 100mm.
4. Confirm ATC Clearances: Run a manual tool changer (ATC) test cycle at low speed to verify the automatic arm smoothly grabs, seats, and releases the BT50 taper without physical interference.

Technical FAQ