Views: 0 Author: Site Editor Publish Time: 2026-08-20 Origin: Site
Within the Xinda XDT portable boring machine family, the XDT40/50 cover small bores of φ45–260 mm, the XDT60 guards medium-size engineering machinery hinge holes at φ65–500 mm, and the XDT90 — with its φ90 × 7.5 m long bar — guards the "long-span, multi-hole, single-setup alignment" segment. But when the job steps up to the class of "large-bore heavy-duty work" — above φ220 mm, deep holes, hard build-up weld layers on cast steel parts, and ferocious cutting reaction forces — the rigidity reserve of the φ90 bar hits its critical point.
Large-bore boring of heavy structural components is a different problem in the maintenance world:
First, the cutting reaction force is ferocious. Boring a cast steel hinge hole at φ400–800 mm, with a 3–5 mm build-up weld layer on the single side, subjects the bar to several thousand newtons of cutting force. At a 6-meter span, deflection of the φ90 bar starts to become pronounced, and roundness drifts from 0.03 mm toward 0.05 mm and worse.
Second, the hole is deep with significant overhang. Jobs like stern tube shafts in shipyards and the roots of electric shovel crowd arms often have depths of 400–600 mm. The φ90 bar, extended out at such overhang, suffers end-face chatter and the surface develops waves.
Third, the workpiece simply cannot be removed. A stern tube is connected to the entire stern structure of the ship; the root of an electric shovel crowd arm is a cast steel part weighing hundreds of kilograms. Remove it and send it to a heavy horizontal borer? Dry dock days run into six figures, and mine downtime burns money by the hour.
The XDT110 is oriented toward "heavy-duty" within the portable boring category; its hardware is configured for "large bore, long span, deep depth of cut":
Boring bar: Made of bearing steel through a special process — high strength, high hardness, high precision, good toughness, with a hard chrome-plated surface that resists rust and wear. It is a notch above ordinary 45# steel bars.
Spindle box mountable at any position on the bar: The power head sits close to wherever the machining face is, reducing bar overhang and enhancing cutting rigidity.
Bearing support: Imported double-row spherical cylindrical roller bearings — high precision and high rigidity.
Facing head: Capable of forward/backward automatic feed with adjustable feed rate, and can be split apart for easy assembly/disassembly in narrow spaces. Confined spaces such as shipyard bottom pits and stern tube tunnel compartments can be entered piece-by-piece and reassembled on site, without the need for a heavy-tonnage crane.
Rapid alignment: Advanced structure with fast installation — critical for large-bore field operations. When the φ110 bar passes through a φ600 hole, alignment must be completed within half an hour.
The XDT110's φ220–800 mm range (extendable up to 1500 mm) covers the domain of "heavy structural components + marine foundations" thoroughly:
⚓ Ship Stern Tubes & Rudder Systems (core scenario)
Stern tube bores of φ400–700 mm, rudder pintle holes of φ250–450 mm, and rudder horn holes — this is the most representative battlefield for the XDT110. Progress must be made fast within the dry dock cycle: the φ110 bar passes through the stern tube, the support base is welded to the parent metal on both sides of the tube, the workpiece stays put, and the hole is re-bored round on site. The facing head's forward/backward automatic feed and splittable design allow piece-by-piece transport and reassembly in confined spaces like stern tube tunnel compartments, without heavy-tonnage crane support.
⛏ Mining Electric Shovels & Heavy Excavators
Electric shovel crowd arm roots at φ300–600 mm, bucket rod ear holes at φ500–800 mm, and mining shovel saddle bearing bores. With 3–5 mm single-side build-up weld on cast steel, the XDT110 takes on ≥3 mm single-side depth of cut head-on, completing deep 400–600 mm holes in one pass without relay setups.
Port Cranes & Heavy Lifting Equipment
Large port crane hinges at φ250–500 mm, and slewing bearing mounting holes at φ400–800 mm. 380 V three-phase power is readily available on site; the φ110 bar's rigidity handles large-bore deep holes with ease.
Metallurgy & Large Equipment Manufacturing
Rolling mill stand window large bores, large hydraulic press column holes, and marine diesel engine block main bearing bores. These jobs weigh from several tons to dozens of tons per piece; removing them for a heavy horizontal borer would take weeks. The XDT110 does it on site, with single-setup alignment for spans ≤6 m.
Offshore Engineering & Heavy Structural Components
Offshore platform pile leg pin holes, jacket node holes, and large floating crane hinge points. With a φ110 bar and welding fixation, the work gets done right on the deck of an offshore platform.
This is the key question in model selection. The division of labor in the large-bore segment of the Xinda XDT family is now clear:
Need a longer span (>6 meters) → Choose the XDT90 (7.5 m φ90 bar); the XDT110's maximum span is 6 meters.
Need greater rigidity, deeper depth of cut, and a mandatory φ110 bar → Choose the XDT110; for bores above φ220 mm, the φ110 bar provides substantially higher rigidity reserve.
Need to machine φ800–1500 mm large bores → The XDT110 is the only choice; the XDT90 tops out at φ800.
The configuration logic for most shipyards and heavy mining repair shops: the XDT90 guards the φ95–800 mm range at 7.5 m long span, while the XDT110 guards bores above φ220 mm that demand φ110 bar rigidity. Together, the two leave no gap across the entire φ95–1500 mm range.
Distilled from the experience of shipyard dock-bottom crews and mining electric shovel maintenance teams:
① Weld the support base to solid parent metal.
When the φ110 bar rotates, the cutting reaction force is substantial. Before tack-welding the support base, use an angle grinder to expose bare metal, and ensure continuous, non-porous welds. Experience from stern tube work in shipyards: weld the support base to solid parent metal to avoid displacement during machining caused by porous welds.
② Do not mix the nylon centering taper sleeves across sizes.
The machine comes with nylon locating taper sleeves; select the corresponding size according to bore diameter. Forcing a φ400 taper sleeve into a φ600 hole throws off self-centering, and the bored hole group ends up offset.
③ Start the facing head feed from the slow setting.
A single-side depth of ≥3 mm on cast steel is the upper limit; actual recommendation is 1.5–2 mm layered passes, with the feed knob starting slow. For large-bore deep-hole cutting, surface quality matters more than depth of cut.
④ Select among three support devices according to working conditions.
The XDT110 offers optional cross / center / plane support fixtures: for deep holes like stern tubes, choose a plane support + center support combination; for open-working conditions like electric shovel crowd arm roots, choose the cross support; for marine foundations, choose the plane support. If the support method is wrong, even the most rigid φ110 bar cannot deliver its full potential.
(This article is compiled from publicly available corporate materials and industry information for reference only. Specific product information and service terms are subject to the official release of the enterprise.)
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