Product Overview

Many machine shops possess a large inventory of high-quality, large-diameter cutting tools (such as heavy-duty end mills, shell mill arbors, or large twist drills) that utilize a traditional Morse Taper (MT) shank. The SK to MTB Adapter provides a highly rigid and precise method to utilize these tools in modern DIN 69871 (SK/DAT) CNC milling machines. The "MTB" designation specifically refers to Morse Taper tools that have an internal thread at the rear of the shank. These tools are secured into the adapter using a built-in draw screw, which positively locks the taper and completely prevents the tool from pulling out during heavy milling or radial loads.

Key Features & Advantages

• Positive Draw-Thread Locking (MTB): Unlike tang-style (MTA) adapters used only for drilling, the MTB adapter features an internal draw screw that threads directly into the back of the Morse Taper tool. This guarantees absolute security against tool pull-out during aggressive milling operations.

• High Precision Runout: Both the external SK machine taper and the internal Morse Taper bore are precision-ground simultaneously. We guarantee a maximum Total Indicator Runout (T.I.R.) of ≤ 0.005mm (5 microns), ensuring excellent concentricity and extending the life of your cutting tools.

• Maximum Rigidity: Forged from premium alloy steel (such as 20CrMnTi) and case-hardened to HRC 56-60. The robust, single-piece construction of the adapter body absorbs heavy machining vibrations, preventing chatter and ensuring superior surface finishes.

• Protects Spindle Accuracy: By using a dedicated, high-quality adapter, you protect your machine's expensive spindle taper from the wear and tear associated with frequently changing large, heavy Morse Taper tools.

• High-Speed Dynamic Balancing: Dynamically balanced to G6.3 @ 15,000 RPM to protect your machine's spindle bearings and ensure smooth operation during modern CNC machining cycles.

Why Partner with Pingyuan Zhenghao Machinery?

• Direct Manufacturer Savings: Bypass trading companies and source precision CNC reduction sleeves directly from our factory for highly competitive wholesale pricing.

• Complete SK Spindle Compatibility: We manufacture adapters for the most common European-style V-flange tapers: SK40 (the industry standard) and SK50 (for large, heavy-duty horizontal and vertical mills).

• Full Morse Taper Range: Available to accommodate all standard MTB shank sizes: MT1, MT2, MT3, and MT4, covering a vast range of tool diameters.

• Strict Quality Control: Every adapter is inspected using taper gauges (AT3 standard) to verify the exact angle and contact area of both the internal MT bore and the external SK taper.

Frequently Asked Questions (FAQ) - Selection Guide

Q1: What is the difference between an MTA and an MTB Morse Taper Adapter?

A: This is a critical distinction:

• MTA (Morse Taper with Tang): The tool has a flat "tang" at the end. It relies purely on friction to hold the tool and the tang prevents rotation. MTA is strictly for drilling and reaming (axial loads only). If you try to mill with an MTA tool, the side loads will cause the taper to loosen and the tool will fall out.

• MTB (Morse Taper with Drawbar Thread): The tool has an internal threaded hole at the rear. The adapter has a built-in screw that pulls the tool tightly into the taper. MTB is designed for milling (radial loads) because the screw positively locks the tool in place, preventing pull-out.

Q2: How do I know which MTB size I need (MT1, MT2, MT3, MT4)?

A: You must measure the large end diameter of the Morse Taper shank on your cutting tool:

• MT1: Approx. 12.065mm (0.475")

• MT2: Approx. 17.780mm (0.700")

• MT3: Approx. 23.825mm (0.938")

• MT4: Approx. 31.267mm (1.231") Match this size to the corresponding SK40 or SK50 adapter.

Q3: Does the adapter include the locking draw screw?

A: Yes, all of our SK MTB adapters come fully assembled with the internal draw screw required to secure your threaded Morse Taper tool.

Q4: Can I use this holder in a BT40 or CAT40 machine?

A:No. While SK40, BT40, and CAT40 all share the same 7/24 taper angle, the V-flange design (for the automatic tool changer) is completely different. This SK (DIN 69871) adapter will only work correctly in a machine spindle designed for SK/DAT tooling.

Securely integrate your heavy-duty Morse Taper tooling into your CNC process with our Precision SK MTB Adapters.

Contact our sales team today for a complete catalog and bulk pricing.