Precision Bore
Repair, On-Site.

A portable line boring machine is a field-deployable system that restores worn cylindrical bores to their original diameter and tolerance without removing the component from the equipment. The machine mounts directly inside the worn bore using adjustable bearing supports, then rotates a precision boring bar driven by a servo motor to cut the bore back to specification. BOS machines combine this boring capability with automatic MIG welding — allowing operators to build up severely worn bores before finish boring, all in one setup.

BOS line boring machines are used on any heavy equipment with cylindrical pin bores — excavators, backhoe loaders, bulldozers, motor graders, stone crushers, cranes, road rollers, mining shovels, haul trucks, marine vessels, wind turbines, railway bogies, and industrial plant machinery. The BOS-DS50 covers bores from 55–160mm for standard construction and earthmoving equipment, while the BOS-DS60 handles 65–600mm for larger mining and industrial applications.

BOS machines deliver ±0.01mm positioning accuracy and Ra 3.2 surface finish — equivalent to workshop lathe results. The servo motor control system provides repeatable feed and rotation control that eliminates operator variation. Ellipticity tolerance of ±0.02mm is achievable on every repair, meeting or exceeding OEM bore specifications. Field conditions do not compromise accuracy — the rigid boring bar and precision bearing supports ensure consistent results regardless of site environment.

The BOS-DS50 handles bore diameters from 55–160mm with a 3100W servo motor, 130 N.m torque, and Ø50mm boring bar — ideal for standard excavators, backhoe loaders, and most common earthmoving equipment. The BOS-DS60 handles 65–600mm with a 3800W motor, 220 N.m torque, Ø60mm bar, and three bearing support configurations for larger bores — suited to large excavators, stone crushers, cranes, and mining equipment. Both offer the same 5-function platform.

No — BOS machines are designed for field deployment without any special facility. You need a standard 220V or 380V power supply (generator compatible), the BOS machine kit, and a trained operator. The machine can be set up on active construction sites, open-cut mines, marine vessels, and remote locations. PR Crane & Earthmovers provides full operator training at the time of purchase to ensure your team can deploy and operate the machine independently from day one.

A straightforward line boring job on a single pin bore typically takes 2–4 hours from setup to completion. When welding is also required — building up a severely worn bore before finish boring — total time is typically 4–8 hours per bore. Compare this to 5–15 days for conventional workshop repair including dismantling, transport, workshop queue time, and reassembly. For fleet operators and mining companies, this time saving directly translates to revenue recovery from equipment returned to service faster.

BOS machines are available across India through PR Crane & Earthmovers, with the head office in Udaipur, Rajasthan and a branch office in Bangalore, Karnataka. Export supply is available to Southeast Asia, Middle East, and Africa. After-sales support includes operator training, spare parts supply, and technical assistance via phone and email. Contact Prakhar Bhardwaj at +91 99015 85506 or prakhar@wearebos.in, or Pankaj Bhardwaj at +91 79768 34856 for enquiries.

Both BOS-DS50 and BOS-DS60 operate on standard 220V or 380V single or three-phase power at 50–60Hz. The DS50 servo motor draws 3100W and the DS60 draws 3800W — a 5–6 kVA generator is sufficient for field operation where mains power is unavailable. This makes BOS machines fully deployable to remote mine sites, offshore vessels, and construction sites without access to permanent power infrastructure. Voltage selection (220V or 380V) can be specified at the time of order.