Machining examples for slide boring bars

When using our slide boring bars to produce complex workpiece contours, the possibilities are virtually endless! Take a look at our examples to see which challenges we've already successfully met with our customers.

Workpiece: hydraulic block

Machining with a rotary-driven slide boring bar

The adjusting spindle is driven by the machine-side transverse feed unit. The slide boring bar is used in hydraulic block manufacturing to machine the transition from the main hole to the transverse hole. The slide stroke is 18 mm with an external diameter of 50 mm. You can change the indexable insert seats to match the machining process (Semi, Finish).

The modular design enables the boring bar to be extended using an adapter. The boring bar is 458 mm in length (HSK100 flange to cutting edge), with an adapter of 790 mm.

Operational sequence:

  • Enter workpiece vertically and position counter bearing
  • Retract to centre of transverse hole
  • Spindle to machining speed
  • Excavate the transition (forwards and backwards) 
  • Boring bar to centre of transverse hole
  • Spindle stop
  • Move out of the hole vertically
  • The counter bearing is removed from the bearing hole

Cutting data:
n = 260 rpm 
vc = 116 – 130 m/min 
vf = 52 mm/min
f = 0.20 mm/rev 
fz = 0.10 mm/rev

    1. Counter bearing 
    2. Slide 
    3. Adapter interface

Workpiece: engine block

Machining: cylinder bore in engine blocks with cooling water-controlled fine-boring system

The cutting edges are extended by supplying the tool with 40 bar (TCS). The pressure is released at the bottom of the hole, allowing the cutting edges to return to their previous position. The tool can be moved out of the fit at high speed G0 without affecting the contour! Cutting adjustment is performed via the machine control system/spindle.

  • Central cutting adjustment
  • Cutting edge removal above TCS 40 bar

Material 3.3206 (AlSi7MgCu0.5)

Cutting data:
vc = 500 m/min
vf = 1415 mm/min
ap = 0.35 mm in radius
f = 0.75 mm/rev
n = 1887 rpm
Radius surface Rz 25.8

Workpiece: gearbox housing (bearing seats)

Machining: finish-machining bearing seats with a bridge tool

  • Finish-machine bearing seats to Ø 80H7 / Ø 100H7
    with a bridge tool
  • Axially retract the counterboring cutting edges
  • Face turning with transverse feed

Cutting data:
Ø 80 / 100 mm
vc = 400 m/min
n = 1591 rpm
f = 0.11 mm/rev
vf = 175 mm/min

Workpiece: gearbox housing

Machining: highly complex multi-purpose tool for machining gearbox housings in one pass

  • Boring the hole Ø 25/220/227 mm and outer Ø 46 with rigid cutting edges
  • Face turning with transverse feed Ø 226 / 206 mm
  • Face turning of the bearing blind hole Ø 220 mm and
    external face turning Ø 46 mm
  • Housing base is also grooved with a
    grooving insert

Cutting data:
Ø 25 – 227 mm
vc = 161 – 1450 m/min
n = 2000 rpm
f = 0.1 mm/rev
vf = 200 mm/min

Workpiece: pipe end machining

Machining: different operations combined with fixed and actuated snap-on tools

  • Chamfering of the hole
  • Internal turning with undercut for thread run-out
  • External chamfering and spotfacing with fixed snap-on tools
  • Thread turning (combing) in several steps
  • It is possible to machine different workpieces by exchanging the central tools

Cutting data:
Ø 94 mm
vc = 220 m/min
n = 1350 rpm
f = 0.12 mm/rev
vf = 162 mm/min

Workpiece: bearing housing

Machining: multi-purpose tool for rough turning, finish turning and face turning

  • Rough turning with Ø 40 mm boring bar and 1×45° chamfer as well as outer Ø 95 mm and Ø 86 mm step 
  • Remove cutting edges 
  • Transverse feed on face and face turn pre-grooved step

Cutting data:
Ø 50 mm / Ø2 110 mm
vc = 180 m/min
n1 = 1150 rpm
n2 = 520 rpm
f = 0.15 mm/rev
vf1 = 172 mm/min
vf2 = 80 mm/min

Workpiece: cylinder head/valve seat

Machining: producing the valve seats and tappet guide in a single operation

  • Copy milling the protective countersink 120° by actuating the machine axis and the transverse feed unit (coordinated to one another)
  • Sealing seat 90°–30’ by actuating the transverse feed unit
  • Protective countersink 60° 
  • Reaming of the tappet guide

Cutting data:
Ø 38.6 – 23 mm
vc = 242 – 144 m/min
n = 2000 rpm
f = 0.08 mm/rev
vf = 160 mm/min

Workpiece: shaft machining

Machining: facing slide for external machining of long shafts

Facing slide with central hole for workpiece leadthrough (if required it is possible to mount the rotating centring tip)

Cutting data:
Ø 37 – 12 mm
vc = 260 – 34 m/min
n = 2240 rpm
f = 0.1 mm/rev
vf = 224 mm/min