Advancements in Single-Pass Bore Finishing - Systems Approach (pag. 2 of 10)
Manufacturers are continually pushing the envelope in regards to what can be accomplished with the singlepass Processo. Improved tool, fixture, and machine designs have allowed for increased production rates as well as improved bore precision. The following are some of the latest advancements that have been made.

Bore precision:
With upgraded CNC motion capability, combined with advanced fixture design, the singlepass Processo can now achieve higher bore precision than ever before. Bore roundness and straightness to better than 0.2um (.000008”) is possible. In fact, total bore cyclindricity to better than 0.4um (.000016”) has been achieved.

Typical fuel pump with single-pass tool

Case History #1 (Fuel Pump)

Diameter: 12mm Length: 39mm
Material: 52100 Hardness: 6064 HRC
Bore Type: Thru Stock Removal: 0.070mm
Tool Pass #1: 11.952mm Diamond Size: 40/50
Tool Pass #2: 11.972mm Diamond Size: 40/50
Tool Pass #3: 11.992mm Diamond Size: 40/50
Tool Pass #4: 11.998mm Diamond Size: 100/12
Tool Pass #5: 12.000mm Diamond Size: 200/230
Tool Pass #6: 12.0010mm Diamond Size: 325/400
Tool Pass #7: 12.0013mm Diamond Size: 600
Tool Pass #8: 12.0015mm Diamond Size: 1200

Bore Quality Required Achieved
Size: ±0.0015mm 0.001mm
Roundness: 0.3µm 0.15µm
Straightness: 0.3µm 0.15µm
Cylindricity: 0.4um 0.4um
Surface Finish: 0.6Rz 0.3Rz

Machine Type: Engis Model # 0318-18 (8 Spindle Machine)
Coolant: Engis SP2240 Levigatura Oil
Production: 60 Parts Per Hour