BOCI BLT442 Consumables: M11 Ring and the Shared 4-Series Module
BLT442 sits in the same consumable family as the 421 — with two exceptions
Read against BOCI's official consumable tables, the BLT442 is unusually well documented, which is not true of every model: the ceramic ring is the standard M11×0.75 4-series ring, and the sensor module (the protective-window cartridge) is shared with BLT421 / 441 / 461 / 481 / 4101 / 421S / 462 / 482 / 4102 / 4122 — the 442 is named in that same row.
The two exceptions are the ones that cause wrong shipments: the -P variant takes a different ring (M11×0.75-P, shared only with 442P / 462P / 482P / 4102P), and the T variant moves to the M8×0.75 ring that the tube-cutting range uses.
Consumables by position
| Position | What the 442 takes | What decides the variant |
|---|---|---|
| Ceramic ring | M11×0.75 (4-series ring); -P variant uses M11×0.75-P; T variant uses M8×0.75 | The suffix on the nameplate — 442 / 442P / 442T are three different rings |
| Sensor module / window cartridge | The same module row as the 421 / 441 / 461 / 481 / 482 | Cartridge revision, not the model number |
| Focus module | Listed in the -200 group together with 441 / 461 / 481 / 462 / 482 | Focal length group printed on the module |
| Nozzle | F-series nozzles (S1.2-F … D2.0-F, single and double layer) for the flat head; T-series for the T variant | Body diameter, thread, bore, layer type |
| Sealing ring / body parts | Shared 4-series body and sealing ring, as on the 421 | Head revision |
Note what is deliberately absent: a power rating and a window size per model. BOCI publishes the family rows, not a per-model datasheet, and a focal length printed on a module is more reliable than a number on a web page.
How to confirm a BLT442 order
- Read the full suffix. 442, 442P and 442T are three different rings; the difference is invisible once the nozzle is on.
- Photograph the old ring next to a rule and the old window out of its cartridge.
- Copy the focal group from the focus module marking (-200 group or not).
- We confirm ring, module group and nozzle thread in one reply.
Where BLT442 orders go wrong
- Treating -P as a packaging suffix. It is a different ring with a different seat; a ring that fits but is the wrong suffix reads height badly rather than not fitting at all.
- Ordering a T-series nozzle for a flat 442. The T range is the tube-cutting body; the F-series flat nozzle will not seat on it.
- Buying a module because the window hazes. A window that hazes within a shift is usually gas or contamination; the module is the expensive way to find that out.
FAQ
Does the BLT442 use the same window module as the BLT421?
Yes, in the official table the 442 appears in the same sensor-module row as the 421 / 441 / 461 / 481 / 482. The window inside may still differ by revision, which is why we ask for the old window measurement.
What is the difference between BLT442 and BLT442P?
The ring. The -P variant is listed as a separate ring row (M11×0.75-P) shared with 442P / 462P / 482P / 4102P. Ordering an M11 ring for a -P head gets you a part that seats but reads height incorrectly.
Sources
BOCI consumable tables (bochu.com/pro_en/consumable), read 2026-11-09: ring rows, sensor-module row, focus-module row, nozzle rows. Part numbers not reproduced.
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.