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BT40 MAS 403 slim shrink fit chuck 3°, Ø3–16 mm

Kortools

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€76.36

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BT40-SFS03-90

BT40-SFS04-90

BT40-SFS06-90

BT40-SFS08-90

BT40-SFS10-90

BT40-SFS12-90

BT40-SFS16-90

BT40-SFS03-120

BT40-SFS04-120

BT40-SFS06-120

BT40-SFS08-120

BT40-SFS10-120

BT40-SFS12-120

BT40-SFS16-120

BT30-SFS03-80

BT30-SFS04-80

BT30-SFS06-80

BT30-SFS06-120

BT30-SFS08-80

BT30-SFS08-120

BT30-SFS10-80

BT30-SFS10-120

BT30-SFS12-80

BT30-SFS12-120

BT30-SFS16-80

BT30-SFS16-120

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Product description

BT40 MAS 403 slim shrink fit chuck 3°, Ø3–16 mm

Slim shrink fit chuck with a BT40 taper to MAS 403 BT (JIS B 6339) taper. The clamping section has a 3° angle (standard shrink fit chuck: 4.5°), so the chuck is narrower at the front: for a Ø6 mm shank the front diameter D is 12 mm (standard: 21 mm). A cylindrical-shank tool is clamped without a collet: the heated bore of the chuck expands, the shank is inserted to the set depth, and as the chuck cools down it clamps the shank around its full circumference. The tool is removed after heating the chuck again.

A shrink fit chuck requires an induction shrink fit unit: without heating, the tool cannot be inserted or removed. The shrink fit unit is not included.

Available for shank diameters Ø3–16 mm in lengths L = 90 and 120 mm. Select the variant when purchasing. Diameters Ø3 and Ø4 mm have no stop screw thread (G “–”): set the tool by its insertion depth.

Applications

clamping end mills, drills and reamers with cylindrical shanks, most often made of solid carbide, especially small diameters
machining in deep and narrow cavities: the slim 3° clamping section reduces the risk of collision
precise machining: holder runout ≤ 0.003 mm
high tool clamping force

Specification

Taper type	BT40 (MAS 403 BT / JIS B 6339)
Tool clamping	shrink fit, slim clamping section with a 3° angle
Tool shank diameter d	3, 4, 6, 8, 10, 12 or 16 mm (depending on variant)
Tool shank	cylindrical, with a diameter equal to d of the variant
Chuck diameter at the front face D	9–22 mm (depending on variant)
Length L	90 or 120 mm (depending on variant)
Holder runout	≤ 0.003 mm
Balance grade	at least G6.3 (many pieces are balanced to G2.5 at 25,000 rpm: ask us and we will check the label of the specific piece)
Coolant	AD version (central coolant supply)
Tool projection setting	thread G for a stop screw in the bore (dimension table), adjustment range 10 mm; the smallest diameters have no thread G (“–” in the table)
Tool insertion and removal	induction shrink fit unit (not included)
Standard	MAS 403 BT / JIS B 6339 (taper)

Balance grade: at least G6.3. Many shrink fit chucks of this series are balanced to G2.5 at 25,000 rpm (more precise). If you need G2.5 for high spindle speeds, write to us before purchasing — we will check the label of the specific piece before shipping.

Coolant: AD version. If your spindle supplies coolant through the flange (form B), write to us before purchasing.

Dimension table

Dimension drawing – BT40 MAS 403 slim shrink fit chuck 3°, Ø3–16 mm

Variant	d [mm]	D [mm]	D1 [mm]	L [mm]	L3 [mm]	L2 [mm]	L1 [mm]	G
BT40-SFS03-90	3	9	15.3	90	63	60.2	–	–
BT40-SFS03-120	3	9	18.3	120	93	88.3	–	–
BT40-SFS04-90	4	10	16.3	90	63	60.2	–	–
BT40-SFS04-120	4	10	19.3	120	93	88.3	–	–
BT40-SFS06-90	6	12	18.3	90	63	60.2	36	M5
BT40-SFS06-120	6	12	21.3	120	93	88.3	36	M5
BT40-SFS08-90	8	14	20.3	90	63	60.2	36	M6
BT40-SFS08-120	8	14	23.3	120	93	88.3	36	M6
BT40-SFS10-90	10	16	22.3	90	63	60.2	42	M8×1
BT40-SFS10-120	10	16	25.3	120	93	88.3	42	M8×1
BT40-SFS12-90	12	18	24.3	90	63	60.2	47	M10×1
BT40-SFS12-120	12	18	27.3	120	93	88.3	47	M10×1
BT40-SFS16-90	16	22	28.3	90	63	60.2	50	M12×1
BT40-SFS16-120	16	22	31.3	120	93	88.3	50	M12×1

d – bore diameter (tool shank), D – chuck diameter at the front face, D1 – diameter at the base of the 3° tapered section, L – length from the flange face (spindle side) to the chuck front face, L3 – length from the front surface of the flange to the chuck front face, L2 – length of the 3° tapered section, L1 – maximum shank insertion depth, G – thread of the stop screw for setting the tool projection (adjustment range 10 mm), N – stop screw adjustment range (10 mm), R – fillet radius at the flange (3 mm), “–” – no thread.

Read the complete designation of the selected variant. For example, BT40-SFS12-90 means a BT40 taper, a slim 3° shrink fit chuck (SFS) for a Ø12 mm shank and length L = 90 mm.

How to select

Check that the spindle has a BT40 interface (MAS 403 BT), not SK40.
Diameter d = tool shank diameter (e.g. an end mill with a Ø12 shank = a variant with “12” in the code). The shank must be cylindrical.
Choose the slim version for small tools and deep, narrow cavities; under heavy load a shorter, thicker 4.5° chuck is stiffer.
An induction shrink fit unit is needed to insert and remove the tool.

FAQ

Will it fit my machine?
The holder has a BT40 taper to MAS 403 BT (JIS B 6339). Before purchasing, confirm that the standard, size and pull stud match the machine spindle requirements. BT40 and SK40 are different tapers, so the designation “40” alone is not sufficient to confirm the selection.

Do I need a shrink fit unit?
A shrink fit chuck requires an induction shrink fit unit: without heating, the tool cannot be inserted or removed. The shrink fit unit is not included.

Which tools can be clamped?
Tools with a cylindrical shank with a diameter equal to d of the selected variant, most often made of solid carbide. The insertion depth must not exceed L1 from the dimension table.

How does it differ from a standard shrink fit chuck?
It has a slim clamping section with a 3° angle instead of 4.5°, so it is narrower at the front (for Ø6 mm: D = 12 mm instead of 21 mm). This makes work in deep and narrow cavities easier. The tool clamping method is the same.