BOCI Cutting Head Consumables
BOCI heads are the ones where the model suffix decides the part: the same BLT number can take a different ceramic ring depending on the letters after it. This chart is organised around that.
Why BOCI needs a suffix-level chart
BOCI (Bochu) sells its cutting heads under BLT model numbers, and the model number alone is not enough to pick a ceramic ring. A BLT421 and a BLT421T are different heads: the first takes the M11 ring, the second takes the M8 ring. The same happens across the power ranges — the high-power BLT6xx heads use the M11 ring, the BLT5xx sheet series uses M8.
That is why this page groups the series by ring thread first and lists the models inside each group. If you know the ring thread, you can find your model; if you only know the model number, find the row and the thread follows.
Ceramic rings by BOCI series
| Ring thread | BLT series covered | Note |
|---|---|---|
| M11×0.75 | BLT310; BLT420 / 420S / 440F / 460F; BLT421 / 441 / 461 / 481 / 4101; BLT442 / 462 / 482 / 4102; BLT421S; BLT640 / 641 / 641H / 642H / 661 / 661H / 662H / 681H / 682H / 6101H / 6102H; BLT662M / 682M / 6102M / 662MA / 682MA | The largest group, and the one that covers most mid and high power 2D heads |
| M8×0.75 | BLT310T; BLT421T / 441T / 461T / 421TS / 442T / 462T; BLT520H / 540H / 560H / 510 / 520 | Tube-cutting and sheet series heads |
| M11×0.75-P | BLT442P / 462P / 482P / 4102P | The -P suffix is a distinct ring, not an M11 ring with a different label |
| M11×0.75-S | BLT4122 / 6120H / 6140H; BLTA120M / A140M / A160M / A180M; BLT980MA / 9100MA / 9120MA | High-power and large-format heads |
Two things this table deliberately does not do. It does not give you a nozzle size per model, because the bore is a process decision, not a model decision — two workshops running the same head on different materials land on different bores. And it does not list a protective lens per model, because the lens is matched to the cartridge revision. Both are a conversation, not a lookup.
Nozzles, lenses and the other consumables
| Part | What we hold | What decides the variant |
|---|---|---|
| Ceramic ring | D28-M11, D31-M11, D32-M14 and D19.5-M8 as standard lines, plus the BOCI D40.8-M11 for the large-format heads | Ring thread and suffix (M11, M8, -P, -S), head series |
| Nozzle | D28 and D32 bodies in single and double layer, coated and uncoated, plus E-type; 3D-M8; Bullet; DNE D15 and D17 | Body diameter, thread, bore, layer type |
| Protective window | 20 sizes from 18×2 to 55×9 mm, rated 4–30 kW | Diameter, thickness, power rating, cartridge revision |
| Focus lens | D30 with FL100 / FL125 in stock; 63.5–254 mm to order | Diameter, focal length, coating |
| Body insulator, retaining cap, seals | Common wear parts for BLT-series heads | Head series and revision |
The ring column is the one that matters on a BOCI head. We hold five ring diameters, and the suffix in your model number is what picks between them — not the BLT number on its own.
Ordering
- Read the nameplate. Copy the full model including the suffix letters.
- Tell us the ring thread if the old ring is still readable, or send a photo of it next to a rule.
- We confirm ring, nozzle thread and lens size in one reply.
- Wholesale and OEM packaging available; kits for a full head overhaul can be grouped into one line item.
Where BOCI heads usually go wrong
- Ordering an M11 ring for a T-suffix head. BLT421 and BLT421T are not interchangeable at the ring, and the difference is invisible once the nozzle is fitted.
- Treating -P and -S as cosmetic suffixes. They identify different rings with different seats. A ring that fits but is the wrong suffix will read height badly rather than not fit at all.
- Replacing the ring to fix a height fault that is actually the cable. If the head did not crash, inspect the cable and shield first.
Related categories
Ruiying is an independent supplier of aftermarket laser consumables. Brand names are used only to indicate compatibility and remain the property of their respective owners. We are not affiliated with, authorised by, or endorsed by these manufacturers. Specifications vary between head revisions — please confirm the full model before ordering.