BT40 MAS 403 Weldon holder with coolant channels Ø6–40 mm
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5-axis vise with hard jaws
Self-centering machine vise. Hard jaws included.
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Product code: 9D39-4278B
Product description
BT40 MAS 403 Weldon holder with coolant channels, Ø6–40 mm
Weldon (side-lock) milling holder with a BT40 (MAS 403 BT / JIS B 6339) taper and coolant channels. The tool is clamped by the side flat of the shank (Weldon, DIN 1835 B) and a clamping screw, so the cutter does not rotate in the holder even in heavy milling. Coolant supplied through the spindle centre flows through channels to the front face of the holder, around the tool, and reaches the cutting zone even when the tool has no internal coolant channels.
Available bore diameters: 6, 8, 10, 12, 14, 16, 18, 20, 25, 32 and 40 mm. Length L = 50 mm (Ø6 and Ø8), 63 mm (Ø10–20), 90 mm (Ø25), 100 mm (Ø6–20 and Ø32) and 120 mm (Ø40). Select the variant when purchasing.
Applications
- clamping end mills, drills and other tools with a Weldon flat shank (DIN 1835 B)
- milling with coolant delivered onto the tool from the holder front face, also with tools without internal coolant channels
- roughing and heavy machining: rigid clamping, the tool does not rotate in the holder
- CNC milling machines and machining centres with a BT40 spindle (MAS 403 BT) and through-spindle coolant
Specification
| Taper type | BT40 (MAS 403 BT / JIS B 6339) |
| Tool clamping | Weldon (side-lock): shank flat and clamping screw |
| Bore diameter d | 6–40 mm (depending on variant) |
| Clamping screws | 1 screw (Ø6–20 mm) or 2 screws (Ø25–40 mm) |
| Coolant | AD version: coolant through the spindle centre exits through channels at the holder front face, around the tool |
| Holder runout | ≤ 0.005 mm |
| Balance grade | G6.3 at 15,000 rpm |
| Material | alloyed case-hardened steel (carburized depth 0.8 ± 0.2 mm) |
| Hardness | HRC 56–60 |
| Taper | taper tolerance < AT3, surface roughness Ra < 0.2 µm |
| Standard | MAS 403 BT / JIS B 6339 (taper), DIN 6359 / DIN 1835 B (Weldon bore) |
Balance grade: G6.3 at 15,000 rpm. If you need a finer balance grade (G2.5) for higher speeds, write to us before purchasing.
Coolant: AD version (coolant through the spindle centre). If your spindle supplies coolant through the flange (form B), write to us before purchasing.
Dimension table
| Variant | d [mm] | D [mm] | L [mm] | M (screw) | Number of screws |
| BT40-SLA06-50K | 6 | 25 | 50 | M6 | 1 |
| BT40-SLA06-100K | 6 | 25 | 100 | M6 | 1 |
| BT40-SLA08-50K | 8 | 28 | 50 | M8 | 1 |
| BT40-SLA08-100K | 8 | 28 | 100 | M8 | 1 |
| BT40-SLA10-63K | 10 | 35 | 63 | M10 | 1 |
| BT40-SLA10-100K | 10 | 35 | 100 | M10 | 1 |
| BT40-SLA12-63K | 12 | 42 | 63 | M12 | 1 |
| BT40-SLA12-100K | 12 | 42 | 100 | M12 | 1 |
| BT40-SLA14-63K | 14 | 44 | 63 | M12 | 1 |
| BT40-SLA14-100K | 14 | 44 | 100 | M12 | 1 |
| BT40-SLA16-63K | 16 | 48 | 63 | M14 | 1 |
| BT40-SLA16-100K | 16 | 48 | 100 | M14 | 1 |
| BT40-SLA18-63K | 18 | 50 | 63 | M14 | 1 |
| BT40-SLA18-100K | 18 | 50 | 100 | M14 | 1 |
| BT40-SLA20-63K | 20 | 52 | 63 | M16 | 1 |
| BT40-SLA20-100K | 20 | 52 | 100 | M16 | 1 |
| BT40-SLA25-90K | 25 | 65 | 90 | M18×2 | 2 |
| BT40-SLA32-100K | 32 | 72 | 100 | M20×2 | 2 |
| BT40-SLA40-120K | 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.
Read the complete designation of the selected variant. For example, BT40-SLA16-63K means a BT40 taper, a Weldon (SLA) holder for a Ø16 mm shank and length L = 63 mm, K – with coolant channels.
How to select
- Check that the spindle has a BT40 interface (MAS 403 BT), not SK40.
- Bore diameter d = tool shank diameter (e.g. an end mill with a Ø16 shank = variant SLA16).
- The tool shank must have a Weldon flat (DIN 1835 B); the clamping screw presses on this flat.
- The holder coolant channels work when the spindle supplies coolant through the centre (AD version).
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.
How does it differ from a standard Weldon holder?
It has channels through which the coolant from the spindle exits at the holder front face, around the tool. In a standard Weldon holder the coolant flows only through the centre, so it reaches the cutting edges only through the tool's internal channels.
Does the tool need a Weldon flat?
Yes. The holder clamps shanks with a flat to DIN 1835 B (Weldon). For shanks with an inclined flat (Whistle Notch, DIN 1835 E) choose a Whistle Notch holder.
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.
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