BMT is not an ISO or DIN standard. It is an industry de-facto standard, so the same nominal size — BMT55, BMT60, BMT65 — can mean different bolt circles on machines from different builders. Several builders skip the nominal size entirely and use their own bolt-hole pattern. The table below lists 38 turret bolt patterns found in published tooling catalogues and the machines that use them.
Mongtec builds driven and static holders for all of these, including the machine-specific ones. Send the machine model and we confirm the fit before quoting →
| Bolt pattern | Machine builder | Example machines |
|---|---|---|
| 30×64 mm | Mori Seiki / DMG MORI | ZL150 |
| 35×76 mm | Mori Seiki / DMG MORI | ZL200 |
| 40×55 mm | Nakamura-Tome | WT100, GTS150, GTS100 |
| 40×55 mm | Muratec | MT100 |
| 44×50 mm | Wasino | A12 |
| 44×60 mm | Takahashi | — |
| 50×50 mm | Biglia | B436Y2, B436 |
| 50×60 mm | Nakamura-Tome | WT150, AS200, WY250, WT100 |
| 52×56 mm | Miyano | — |
| 52×100 mm | Goodway | GS400M |
| 52×100 mm | Mori Seiki / DMG MORI | SL400, UT400 |
| 54×54 mm | Miyano | — |
| 54×70 mm | Muratec | — |
| 55×60 mm | Femco | HL25DM |
| 55×60 mm | EMCO | HL25DM |
| 56×68 mm | Miyano | — |
| 57×54 mm | Wasino | A12 |
| 58×58 mm | Takamaz | XY120 |
| 58×60 mm | Takamaz | XL100 |
| 60×60 mm | Takisawa | LA150 |
| 60×70 mm | Takamaz | X10, XY12 |
| 60×75 mm | Miyano | ABX51, ABX51SYY |
| 62×70 mm | Mori Seiki / DMG MORI | NZ1500, NZ2000 |
| 63×65 mm | Biglia | B465 |
| 64×64 mm | Victor | — |
| 65×73 mm | Okuma | LB3000EX, LB3000 |
| 65×80 mm | Okuma | LT2000EX, LT2000EX16 |
| 68×110 mm | Mazak | QTS200M |
| 69×71 mm | Nakamura-Tome | WT300, WY250L |
| 70×70 mm | Takisawa | EX308, NEX108, NEX108M, FX800 |
| 70×73 mm | Doosan | — |
| 70×73 mm | Victor | — |
| 70×95 mm | Takisawa | — |
| 73×78 mm | Okuma | LT2000EX |
| 78×80 mm | Okuma | LB4000EX |
| 84×94 mm | Mori Seiki / DMG MORI | NL1500, NL1500Y |
| 100×100 mm | Victor | — |
| 125×90 mm | Ikegai | — |
Compiled from published tooling catalogues. A bolt pattern is a physical property of the machine turret, not a proprietary design. Always confirm against the turret drawing for your specific machine and turret version — the same machine model is sometimes shipped with two different turrets.
A BMT turret mounts the holder directly to the turret face with four screws and locates it on keys or a spigot. Two things define the mounting: the bolt pattern (the centre distance between the mounting holes, in mm) and the drive coupling that transmits rotation to the tool. A holder fits only when both match.
Where a builder also publishes a nominal BMT size, use it as a first filter and the bolt pattern as the confirmation. Where no nominal size is published — common on Nakamura-Tome, Okuma, Miyano and Takisawa — the bolt pattern is the only reliable identifier.
No. BMT (Base Mounted Turret) is an industry de-facto standard. It is not published by ISO and it is not published by DIN. VDI, by contrast, is standardised in DIN 69880. This is why two turrets both described as BMT65 can have different bolt circles, key positions and drive couplings.
Because the bolt pattern is what physically decides whether a holder mounts. A nominal size such as BMT60 tells you roughly how big the turret disc is; the bolt pattern — for example 65×73 mm on an Okuma LB3000 EX — tells you where the four screws actually go. Ordering by nominal size alone is the most common cause of a holder that will not bolt on.
Measure the centre distance between the mounting holes on the turret face, or read it from the turret drawing in the machine manual. Send Mongtec the machine model and a photograph of the turret face and engineering confirms it against the drawing. That check is free and takes one email.
Yes. Machine-specific bolt patterns are built to order alongside the standard BMT and VDI ranges, including Mazak 68×110 (S68), Goodway D63, Tsugami TS65 and Takisawa TA60. Describe the operation and the machine.
The full dimensioned drawing is supplied by email once an enquiry is open, so that it matches your actual machine and turret configuration.
All driven tool holder types and turret interfaces · Published article numbers · Live tooling by machine model · Selection guide