The TK Threading Kit turns a Maucotools portable line boring machine into a threading machine: it cuts internal threads on site — and external ones with the dedicated tool holders — at standard pitches from 1.5 to 3 mm and a 45 mm minimum diameter. It fits the Ø40 mm boring bar range: LBM250, LBM400, LBM600, OB200, OB400 and START160.
Out in the field the sequence is almost always the same: welding overlay on the worn seat, boring back to size, and then a thread is needed. Threaded seats in fabricated structures, studs, tie rods, connections on valve bodies. Until now that last step meant a second piece of equipment, or sending the component back to the workshop.
What the TK Threading Kit is
The TK Kit is a variable-pitch attachment that lets a portable line boring machine carry out tapping and internal threading on the component while it stays in place, with nothing to strip down. Add the dedicated tool holders and the same set-up cuts external threads as well.
This is not a generic adapter. It is a complete assembly of dies, tools and adjustments, sized specifically for the Ø40 mm boring bar used across the range.
The key figures:
- Boring bar Ø: 40 mm (1.57")
- Standard thread pitches: 1.5 · 2 · 2.5 · 3 mm
- Minimum thread Ø: 45 mm (1.77")
- Total gross weight: around 8 kg
Those four standard pitches cover most of the threaded seats a maintenance team runs into. For anything else the kit is customisable on request: the pitches are agreed at the order stage, to match the thread being restored. Specifications and contents are on the TK Kit product page.
One point worth settling straight away, because it raises the wrong expectations: the 45 mm minimum diameter is a limit of the kit, not of the machine. An LBM250 still bores from Ø22 mm, but with the TK fitted it will not thread below 45 mm.
Overlay, boring, thread: the step that used to fall outside
The value of the kit is not in the threading itself — any properly equipped workshop can cut a thread. It lies in where the thread is cut.
With Dual System technology, one machine builds the worn seat back up by welding and then bores it to nominal size, without moving the component and without realigning between the two operations. The method is set out step by step in our guide to welding overlay on worn seats.
There was still a break in the cycle, though. Whenever a job finished on a threaded seat, either everything came apart and the component went off to the workshop, or a second machine was brought in and the position had to be found again by hand.
With the TK Kit that stage stays on the component: the line boring machine is already centred on the bore it has just machined, and the thread is cut from that same reference.
It is a question of tooling as well. A tap driven into a tough surface on rough alignment will break — and it will break inside the hole.
Perfect alignment with the freshly bored hole prevents tool breakage even in the hardest materials: the thread starts on the very axis that produced the bore, not on an axis picked up again by eye.
What is in the case
The kit runs to 13 line items on the parts list, for a total gross weight of around 8 kg:
- 1× bar holder block
- 1× male die and 1× female die for each of the four pitches (1.5 · 2 · 2.5 · 3 mm)
- 1× sleeve
- 1× 16 mm tool adjustment ring nut
- 3× threading tools, lengths L = 40, 60 and 100 mm
- 3× threading inserts
Eight kilos travels in one hand. That is the difference between "we'll load it next time" and "it's already in the van": the kit rides along with the machine without eating into the payload, and it is on hand even on the jobs where threading was never quoted for.
Which line boring machines it fits
The TK Kit works with every Maucotools portable line boring machine built around the Ø40 mm boring bar:
- LBM250 DUAL SYSTEM — boring range Ø22–250 mm, 1.8 kW, 20 and 40 mm boring bars
- LBM400 DUAL SYSTEM — Ø42–400 mm, 1.8 kW, 40 mm bar
- LBM600 DUAL SYSTEM — Ø42–600 mm, 1.8 kW, 40 and 60 mm bars
- OB200 — Ø22–200 mm and OB400 — Ø42–400 mm
- START160 — Ø22–160 mm
A single kit covers the whole Ø40 bar range. A workshop running an LBM400 alongside an LBM250 does not buy two accessories, and never has to work out which tooling belongs to which machine: the TK moves from one bar to the other, with the set-up change that involves and nothing more.
The exclusions, to be clear: the LBM600X and LBM800X are not on this list. They run a 60 mm boring bar, outside the scope of the TK Kit.
If you are weighing up which machine in the range covers the diameters across your plant, the configurator cross-references working range, drive and kits and returns a complete configuration in a few steps.
Where an in-situ thread earns its keep
The recurring situations are few, and they come back unchanged in very different industries:
- Earthmoving: threaded connections on excavator booms and frames, bolt seats on plates and mounts that will not come off the machine
- Hydropower: studs on turbine covers and flanges, where the station stays down until the unit is closed back up
- Oil & Gas: threaded seats in valve bodies, connections on skids and process structures
- Heavy fabrication: tie rods, stud seats and threaded connections on structures welded in place
External threading takes care of the other half of the caseload: rods, pins and shanks whose thread has been ruined by tightening or corrosion and which, once built back up by welding, have to be re-cut to size. On the TK this is done by adding the dedicated tool holders: the machine and the kit stay the same, only the tooling at the working end changes.
The common denominator never changes: the component is too big, too built-in or too awkward to remove, and the thread is the last small detail holding up everything else. If you are starting from scratch and want to know how a portable machine is chosen by diameter and by sector, the criteria are set out in our complete guide to line boring.
TK Threading Kit: frequently asked questions
Which thread pitches does the TK Kit cut?
The standard pitches are 1.5 · 2 · 2.5 · 3 mm, with one male die and one female die for each pitch. Because it is a variable-pitch kit, other pitches can be supplied on request and are agreed at the order stage.
What is the minimum threading diameter?
45 mm (1.77"). That is a limit of the kit, not of the line boring machine: a machine that bores from Ø22 mm carries on doing so, but with the TK Kit fitted it will not go below 45 mm of threaded diameter.
Does the TK Kit cut external threads as well?
Yes, with the dedicated tool holders added. In its standard composition the TK is equipped for tapping and internal threading; fit the specific tool holders and the same line boring machine cuts external threads too. For the right configuration for the component in hand, refer to the Maucotools technical department.
Can it be used on the LBM600X or the LBM800X?
No. The TK Kit is sized for the Ø40 mm boring bar and fits the LBM250, LBM400, LBM600, OB200, OB400 and START160. The LBM600X and LBM800X run a 60 mm bar: for threading requirements on those models, the Maucotools technical department is the point of contact.
The TK Kit does not change the way anyone works with a Maucotools portable line boring machine: it completes it. The overlay, boring and threading sequence now closes on the spot, on the same machine and off the same centring, and the component never leaves the plant.
Contents, compatibility and the technical datasheet are on the TK Threading Kit page; for non-standard pitches and bespoke configurations, the Maucotools technical department will advise.
As with any in-situ machining work, welding overlay and threading must be carried out in line with the manufacturer's instructions and the safety rules in force on site.
