Tool Holder BT / BBT40 Weldon / Side Lock
Shipping costs are not included in the price.
Shipping costs are not included in the price.
Weekly deals
5-axis vise with hard jaws
Self-centering machine vise. Hard jaws included.
excl. VAT
Regular price:
Lowest price in the 30 days before the reduction:
Time left
Offer ends 06.11.2026 23:59. Offer applies to the vise + hard jaws bundle only.
Ask about the product
The administrator of personal data is Kortools. We process it to respond to your inquiry. More information regarding the processing of personal data can be found in privacy policy.
Select a product variant:
Individual variants may differ in price
Product code: 8ABB-9804D
Product description
BT30 BT40 BT50 SLN Weldon socket
The BT SLN Weldon milling holder in the MAS 403 / JIS B 6339 standard is intended for mounting shank end mills and other cutting tools with a cylindrical shank. The design of the holder ensures greater mounting stiffness than in the case of classic collets, which translates into more stable operation during machining.
The clamping system is easy to use and allows quick clamping and disassembly of the tool. Thanks to the secure mounting, the cutter does not rotate in the holder during heavier machining, which may occur when mounting in collets.
The holder is particularly suitable for milling requiring greater stiffness, stability and safe transmission of torque.
BBT40 – BT40 with flange face contact (BIG-PLUS)
Variants whose code starts with BBT40- have a BBT40 taper. This is a BT40 taper to JIS B 6339 (MAS 403) with a flange face that contacts the spindle face in a BIG-PLUS spindle. The holder is then seated on the taper and on the flange face at the same time (taper and face contact). This gives a stiffer and more stable seating, especially at high spindle speeds, a repeatable position after every automatic tool change, higher machining accuracy and a better surface finish.
In a standard BT40 spindle (without BIG-PLUS) a BBT40 holder works like a standard BT40 holder: it is seated on the taper only. For such a spindle the lower-priced variant with the code BT40- in the same size is sufficient, if it is on the list.
Before purchasing, check in the machine documentation whether the spindle has the BIG-PLUS system (BBT40). The pull stud is selected in the same way as for BT40 (M16 thread), according to the spindle requirements.
| Taper | BBT40: BT40 with flange face contact (JIS B 6339), for BIG-PLUS spindles; works like BT40 in a standard BT40 spindle |
| Tool shank type | Weldon (side-lock) |
| Bore diameter | 6–40 mm (depending on variant) |
| Clamping screws | 1 screw (Ø6–20 mm) or 2 screws (Ø25–40 mm) |
| Length L | 63 mm (Ø6 and Ø8: 50 mm; Ø25: 90 mm; Ø32: 100 mm; Ø40: 120 mm) |
| Holder runout | ≤ 0.005 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) |
| Material | case-hardened alloy steel (case depth 0.8 ± 0.2 mm) |
| Hardness | HRC 56–60 |
| BBT40 taper | taper tolerance < AT3, surface roughness Ra < 0.2 µm |
| Pull stud thread | M16 (as BT40) |
| Standard | JIS B 6339 (BBT taper), DIN 6359 / DIN 1835-B (Weldon bore) |
BBT40 balance grade: at least G6.3. Many BBT40 holders of this type 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.
BBT40 – dimension table
| Variant | d [mm] | D [mm] | L [mm] | M (screw) | Number of screws |
| BBT40-SLN06-L50 | 6 | 25 | 50 | M6 | 1 |
| BBT40-SLN08-L50 | 8 | 28 | 50 | M8 | 1 |
| BBT40-SLN10-L63 | 10 | 35 | 63 | M10 | 1 |
| BBT40-SLN12-L63 | 12 | 42 | 63 | M12 | 1 |
| BBT40-SLN14-L63 | 14 | 44 | 63 | M12 | 1 |
| BBT40-SLN16-L63 | 16 | 48 | 63 | M14 | 1 |
| BBT40-SLN18-L63 | 18 | 50 | 63 | M14 | 1 |
| BBT40-SLN20-L63 | 20 | 52 | 63 | M16 | 1 |
| BBT40-SLN25-L90 | 25 | 65 | 90 | M18×2 | 2 |
| BBT40-SLN32-L100 | 32 | 72 | 100 | M20×2 | 2 |
| BBT40-SLN40-L120 | 40 | 80 | 120 | M20×2 | 2 |
d – bore diameter (tool shank), D – body diameter, L – length from the flange face (spindle side) to the holder front face, M – clamping screw thread.
Check the full designation of the selected variant. Example: BBT40-SLN12-L63 is a BBT40 taper, a Weldon bore Ø12 mm and length L = 63 mm.
BBT40 – questions
What is the difference between BBT40 and BT40?
BBT40 has the same taper as BT40, but in a BIG-PLUS spindle it also contacts the spindle with the flange face. This taper and face contact makes the seating of the holder stiffer. A standard BT40 holder is seated on the taper only.
Does BBT40 fit a standard BT40 spindle?
Yes. In a standard BT40 spindle a BBT40 holder works like a standard BT40 holder (contact on the taper only). The benefit of the face contact is available only in a BIG-PLUS spindle.
How do I tell a BBT40 variant from a BT40 variant?
By the code: BBT40 variants start with BBT40- (e.g. BBT40-SLN12-L63), standard BT40 variants with BT40- (e.g. BT40-SLN12-L63).
Select a pull stud
For a BT holder compare BT pull studs in the appropriate size.
Confirm the selection against the spindle requirements: head profile and angle, thread, length, bore and seal.
Related products
-
C74F-C524A
Pull Studs 0.00BT30/BT40/BT45/BT50 pull stud (retention knob) for JIS B 6339 tool holders, 45°/60°/90°, through and non-through variants, variants with O-ring
BT30-45, for JIS B 6339 holders - non-through, M12, L43 mm, angle 45° BT30-60, for JIS B 6339 holders - non-through, M12, L43 mm, angle 60° BT30-90, for JIS B 6339 holders - non-through, M12, L43 mm, angle 90° BT30C-45, for JIS B 6339 holders - through bore, M12, L43 mm, angle 45° BT30C-60, for JIS B 6339 holders - through bore, M12, L43 mm, angle 60° + 31 morePrice €3.65Price €2.96without VATShipping costs are not included in the price.
Bestsellers
-
Bestseller
JCD modular drill with replaceable tip - internal cooling, for deep holes | GrotXD
JCD C20-100-3D Ø10~10.9 JCD C20-110-3D Ø11~11.9 JCD C20-120-3D Ø12~12.9 JCD C20-130-3D Ø13~13.9 JCD C20-140-3D Ø14~14.9 + 61 morePrice €69.52Price €56.52without VAT -
Price €17.09Price €13.90without VAT
-
Price €7.07Price €5.74without VAT
-
Price €7.52Price €6.12without VAT
-
Bestseller
Other Accessories 0.00CNC Chip Fan / Chip Blower
Complete CNC chip fan Kit: blades, springs, pins and screwsPrice €53.56Price €43.55without VAT -
Bestseller
Ball Nose End Mills 0.002-Flute Carbide Ball Nose End Mill - HYPERCUT
Ø1xR0.5x4Dx50L Ø1.5xR0.75x4Dx50L Ø2xR1x4Dx50L Ø2.5xR1.25x4Dx50L Ø3xR1.5x3Dx50L + 26 morePrice €10.09Price €8.21without VAT -
Bestseller
2-Flute End Mills 0.002-Flute Carbide End Mill for Aluminium
Ø1x3x4Dx50L Ø1.5x4x4Dx50L Ø2x6x4Dx50L Ø2.5x7.5x4Dx50L Ø3x9x3Dx50L + 31 morePrice €5.33Price €4.33without VAT -
Bestseller
2-Flute End Mills 0.002-Flute Carbide End Mill for Steel 55 HRC - TiSiN - Solid Carbide
Ø6x24x6Dx75L Ø8x25x8Dx75L Ø4x20x4Dx100L Ø5x30x5Dx100L Ø6x30x6Dx100L + 31 morePrice €4.38Price €3.56without VAT -
Bestseller
Ball Nose End Mills 0.002-Flute DLC Coated Carbide Ball Nose End Mill| DuraEdge Alu
Ø1.0xR0.5x4Dx50L Ø1.5xR0.75x4Dx50L Ø2.0xR1x4Dx50L Ø2.5xR1.25x4Dx50L Ø3.0xR1.5x3Dx50L + 34 morePrice €7.85Price €6.38without VAT -
Bestseller
2-Flute End Mills 0.002-Flute End Mill for Aluminium | VHM | Miniature Ø0.3 - Ø0.9
Ø0.3x2x4Dx50Lx2T Ø0.3x3x4Dx50Lx2T Ø0.3x4x4Dx50Lx2T Ø0.4x2x4Dx50Lx2T Ø0.4x3x4Dx50Lx2T + 28 morePrice €7.95Price €6.47without VAT -
Bestseller
Ball Nose End Mills 0.002-Flute TiSiN Coated Carbide Ball Nose End Mill
Ø1xR0.5x4Dx50L Ø1.5xR0.75x4Dx50L Ø2xR1x4Dx50L Ø2.5xR1.25x4Dx50L Ø3xR1.5x3Dx50L + 38 morePrice €7.24Price €5.89without VAT -
Bestseller
3-Flute Carbide Corner Radius End Mill for Aluminium| AL DLC
Ø1xR0.1x4Dx50L Ø1xR0.2x4Dx50L Ø1xR0.3x4Dx50L Ø1.5xR0.1x4Dx50L Ø1.5xR0.2x4Dx50L + 137 morePrice €5.89Price €4.79without VAT -
Bestseller
3-Flute End Mills 0.003-Flute Carbide End Mill VHM Z-3 for Aluminium| TriMill AL
Ø1x3xD4x50L Ø1.5x5x4Dx50L Ø2x6x4Dx50L Ø2.5x8x4Dx50L Ø3x9x3Dx50L + 41 morePrice €5.08Price €4.13without VAT -
Bestseller
Countersinks 0.003-Flute Countersink Fi4.5-fi60, 90° - HSS-CO - 5% Kobaltu | Straight Shank
Ø4.5 x 4 x 90° x 40L Ø5 x 5 x 90° x 45L Ø6.3 x 5 x 90° x 45L Ø8.3 x 6 x 90° x 50L Ø10.4 x 6 x 90° x 50L + 12 morePrice €4.79Price €3.89without VAT -
Bestseller
3-Flute End Mills 0.003-Flute DLC Coated Carbide End Mill | TriMill DLC AL
Ø1x3x4Dx50L Ø1.5x5x4Dx50L Ø2x6x4Dx50L Ø2.5x8x4Dx50L Ø3x8x3Dx50L + 38 morePrice €5.05Price €4.10without VAT -
Bestseller
3-Flute End Mills 0.003-Flute HRC65 DLC Coated Carbide End Mill, U-Shaped Flute, for Aluminium | DuraEdge3 Alu
Ø1x3x4Dx50L Ø1.5x5x4Dx50L Ø2x6x4Dx50L Ø2.5x8x4Dx50L Ø3x9x3Dx50L + 40 morePrice €6.73Price €5.47without VAT
