Large bores. Precision concentric. ±0.005 mm.

Diameter above 50 mm (reamers become expensive and unwieldy above this size). Position-critical bores where drift matters (drilling wanders slightly, boring corrects). Roundness-critical applications (boring achieves better roundness than drilling). Bores where dimensions change multiple times during development (boring can adjust to any diameter; reamers are fixed-size).

Machining multiple bearing bores in a single straight-line pass with a long boring bar. Essential for engine crankshaft bearings, camshaft bearings, transmission gear shafts. The bar spans all bore locations, ensuring they're perfectly concentric (within ±0.01 mm). Cannot be achieved by boring each bore independently — individual errors would compound to unacceptable misalignment.

Standard CNC boring: ±0.01 mm position tolerance, adequate for most precision applications. Jig boring: dedicated ultra-precision boring machine with lead screw accuracy of ±0.002 mm, temperature-controlled environment, specialized for position-critical bores. Used for: injection mold plates, precision tooling, aerospace tooling plates where bore positions must be within 0.005 mm of specified location.

Boring produces excellent roundness — typically 0.005 mm on standard production. For critical cylindricity (round both in cross-section and along length), boring with rigid boring bar setup + cylindrical grinding for finish is the path. Hydraulic cylinder bores often boring + honing for optimal combination of dimensions and surface finish.

Boring takes longer than drilling per inch of depth. Boring cycle time: 100–500 mm/min feed rate. Drilling: 500–1500 mm/min. For shallow holes, drill is faster; for deep holes or precision, boring is required regardless of time. Boring cost is justified by accuracy, not speed.

Our line boring capacity: up to 2 m span across multiple bearing houses, bore diameter 50–300 mm. Larger via specialty partners. For line bored engine blocks, crankcases, and multi-bearing assemblies, plan 7–14 day lead time including setup, boring cycle, and inspection. Line boring is a specialty operation — setup time is significant but production quality is exceptional.