Cutting Tools Reference Library · Technical Reference
Taper Shank (Morse Taper) Drills
Taper shank drills have a Morse taper shank with a tang that seats directly in a machine spindle or in a sleeve. This sheet covers how to identify them, how sleeves and sockets adapt them and how to remove them safely.
Draft, open for review. Check every value against the governing standard and the manufacturer’s data before use.
What it is
A taper shank drill has a body like a twist drill and a shank ground to a Morse taper. The taper is self-holding: friction between the taper and the spindle bore drives the drill. A flat tang at the end of the shank fits a slot in the spindle. The tang keeps the drill from slipping out and gives a place for a drift to push the drill out. Taper shank drills are made from small sizes up to large diameters. Drill sizes are covered with other twist drills in ANSI B94.11M and in DIN 345. The tapers themselves are defined in ASME B5.10 and ISO 296.
How to identify
The shank is tapered, not round, and ends in a flat tang. The Morse taper number (MT1, MT2, MT3 and up) is usually marked on the shank or listed in the catalog. Larger drills use larger tapers, but the drill size range for each taper varies by maker. Measure the large end of the taper and compare it to the Morse taper dimensions chart if the marking is worn.
Parts of a taper shank system
| Part | What it does | Notes |
|---|---|---|
| Drill body and flutes | Cuts the hole | Same point and finish options as other twist drills |
| Morse taper shank | Locates and drives the drill | Taper number set by drill size |
| Tang | Prevents slip; drift contact point | Do not use the tang as the main drive |
| Sleeve | Steps a smaller taper up to a larger spindle | For example an MT2 drill in an MT3 spindle |
| Socket | Extends or steps a taper | Longer than a sleeve |
| Drift | Wedge driven through the spindle slot to remove the drill | Use the correct drift, not a screwdriver |
Key points
- Confirm the spindle taper on the machine before ordering. A drill press, lathe tailstock and radial drill may each be different.
- Sleeves let one machine run several taper sizes. Stock common sleeve combinations.
- Clean the taper and the spindle bore. Chips or burrs on the taper cause runout and spinning.
- A drill that spins in the taper damages both the shank and the spindle. Replace galled sleeves.
- Hold the drill when drifting it out so it does not fall onto the table.
Common mistakes
- Ordering by drill diameter without confirming the Morse taper number.
- Assuming a sleeve is the same as a socket.
- Running large taper shank drills at speeds meant for small drills. See the SFM to RPM chart.
- Hammering a drill out from the cutting end instead of using a drift.
Governing standards: ANSI B94.11M (twist drills); ASME B5.10 and ISO 296 (machine tapers); DIN 345 (taper shank twist drills). See the Morse taper dimensions chart.
Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.
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