A turret station is a flat face with a bolt pattern and, usually, a coolant port. A tool block bolts to that face and presents a boring bar or a square-shank turning tool at the right height and the right centre. It is the cheapest part of a lathe's tooling and the one that decides whether the tip lands on centre.
Unlike a BMT or VDI holder, a tool block is not a standardised interface. Bolt spacing, block height, coolant routing and the tool centre height are set by the machine builder, and they change between models and sometimes between production years of the same model. That is why this section is organised by lathe rather than by product code: the right block is the one cut for your turret, and no amount of shimming makes a near-miss work.
Round tool block — clamps a round boring bar by its shank, listed by bore diameter. The everyday internal-work block.
Round tool block with middle coolant — the same, with coolant routed through the middle of the block to the bar. Use it where the bar has internal coolant and the turret supplies pressure.
Round tool block with back coolant — coolant fed from the back face instead. Which of the two you need is set by where the port sits on your turret, not by preference.
Rectangle tool block — a square-shank seat for a turning tool, listed by slot size. Outer diameter boring holder is the deep-reach variant on the machines that list one.
Overall dimensions are the catalogue's own, in millimetres, in the order printed (length × width × height). A dash means the catalogue prints no figure for that block; it is confirmed in writing at RFQ.
| Block type | Bore / slot | Overall dimension (mm) |
|---|---|---|
| Round Tool Block with Back Coolant | Ø40 | 106*82*90 |
| Rectangle Tool Block | Slot 25×25 | 106*50*90 |
| Block type | Bore / slot | Overall dimension (mm) |
|---|---|---|
| Round Tool Block with Back Coolant | Ø32 | 83*68*75 |
| Rectangle Tool Block | Slot 20×20 | 83*45*80 |
| Block type | Bore / slot | Overall dimension (mm) |
|---|---|---|
| Round Tool Block with Middle Coolant | Ø20/32 | 78*106*89.5 |
| Round Tool Block with Back Coolant | Ø40/32 | 95*106*64.5 |
| Rectangle Tool Block | Slot 25×25 | 98*106*59.5 |
Source: Mongtec BMT Static Tool Holder catalogue, Ver 2026, "Applicable to Lathes" section.
Match the machine model first, then the bore or slot size to the tool you are holding. If your model is not listed, that does not mean nothing fits — send Mongtec the machine make, model, year and a photograph of the turret face with a rule across it, and the block is identified from the bolt pattern.
Where the coolant enters the block. Middle coolant feeds through the centre to the bar; back coolant feeds from the rear face. It is decided by the port position on your turret, so check the turret before ordering rather than choosing on preference.
No. Bolt spacing and tool centre height are what matter, and a block that is a few millimetres out puts the cutting edge off centre — which shows up as a taper, a poor finish, or a nose-radius that does not cut. Blocks are cheap; scrapped parts are not.
They are the catalogue figures, printed here as they appear, and they are useful for checking clearance in the turret envelope. The ordering specification is the machine and turret. Confirm both in writing at RFQ.