Con Rod Case Study

Case Study # 1

Part Name Bore Diameter (Crank) Bore Diameter (Pin)

Connecting Rod –Engine 52.126mm 21.014mm

Material                    Material Hardness

C70 S6 Steel (Crank) Bronze Bushing (Pin) 40 - 45 Rc (Steel)

Stock to be Removed Bore Length  (Crank & Pin)

0.076mm              23.65mm

Model Honing Work Stations Pin Honing Tool Abrasive Crank Honing Tool Abrasive Crank Honing Tool Abrasive

Crank Honing Tool Abrasive       3 for Pin, 3 for Crank D252, D181 D427 Water-Soluble Emulsion

Required Tolerances:

Pin Bore Diameter                       Crank Bore Diameter   Roundness Surface Finish (Ra)

21.014mm +/-0.005mm 52.126mm +/-0.0075mm 0.005mm (Pin) 0.008mm (Crank) 0.5umRa(Pin), 1-3um Ra (Crank)

Pin Bore Diameter                         Crank Bore Diameter Roundness Surface Finish (Ra) Processing Time

21.014mm +/- 0.0025mm 52.126mm +/- 0.004mm 0.003mm (Pin), 0.005mm (Crank) 0.3 um Ra(Pin), 1.7 um Ra (Crank) 200 parts (400 bores/hour)

Case Study # 2

Part Name Bore Diameter (Crank) Bore Diameter (Pin)

Connecting Rod – Engine 51.60mm 18.010mm

Material                     Material Hardness

C70 S6 Steel (Crank) Bronze Bushing (Pin) 40 - 45 Rc (Steel)

Incoming Tolerances:

Stock to be Removed Bore Length  (Crank & Pin)

0.076mm                                    23.50mm

Barnes Processing Machine & Tooling: 

Model Honing Work Stations Pin Honing Tool Abrasive Crank Honing Tool Abrasive Coolant

MSSP1000-L3 3 for Pin, 3 for Crank D252, D181 D427 Water-Soluble Emulsion

Pin Bore Diameter                         Crank Bore Diameter Roundness Surface Finish (Ra)

18.010mm +/-0.0075mm 51.600mm +/-0.005mm  0.008mm (Pin) 0.005mm (Crank) Rz6(Pin), Rz2.5 (Crank)

Pin Bore Diameter                          Crank Bore Diameter Roundness Surface Finish (Ra) Processing Time

18.010mm +/- 0.004mm 51.600mm +/- 0.0025mm 0.005mm (Pin), 0.003mm (Crank) <Rz6 (Pin),  <Rz2.5 (Crank) 200 parts (400 bores/hour)

Case Study # 3

Part Name Bore Diameter (Crank) Bore Diameter (Pin)

Connecting Rod – Engine 56,876mm 21.018mm

Material                     Material Hardness

Forged Steel (Crank) Bronze Bushing (Pin) 40 - 45 Rc (Steel)

Stock to be Removed Bore Length  (Crank & Pin)

0.076mm                                     23.85mm

Barnes Processing Machine & Tooling:

Model Honing Work Stations Pin Honing Tool Abrasive Crank Honing Tool Abrasive Crank Honing Tool Abrasive

MSSP1000-L4                              4 for Pin, 4 for Crank D252, D151, D76 D427, D252, D151 Water-Soluble Emulsion

Pin Bore Diameter                         Crank Bore Diameter           Roundness Surface Finish (Ra)

21.018mm +/-0.003mm 56.876mm +/-0.005mm  0.005mm (Pin) 0.008mm (Crank) 0.5umRa(Pin), 1-3um Ra (Crank)

Pin Bore Diameter                           Crank Bore Diameter Roundness Surface Finish (Ra) Processing Time

21.018mm +/- 0.0015mm 56.876mm +/- 0.0025mm 0.003mm (Pin), 0.005mm (Crank) 0.3 um Ra(Pin), 1.7 um Ra (Crank) 300 parts (600 bores/hour)

Case Study # 4

Part Name                                     Bore Diameter (Crank)

Connecting Rod – Diesel Engine 103.50mm

Material                                             Hardness

Steel – Carbon (15B40 Modified) 60 - 63 Rc

Stock to be Removed                       Bore Length

0.050mm – 0.10 (crank end only) 42.0mm

Model Honing Work Stations Honing Tool Abrasive Coolant

HV-5000                        1 57A Oil

Bore Diameter Roundness Surface Finish (Ra) Straightness

+0.0127mm             0.0127mm 0.6 -  2.5um 0.0127mm

Bore Diameter                       Roundness Surface Finish (Ra) Straightness Processing Time/Bore

<0.005mm <0.005mm 1.6 um <0.005mm 25 seconds/bore average

Case Study # 5

Part Name Bore Diameter (Crank) Bore Diameter (Pin)

Connecting Rod             38.07mm, 44.28mm 24.3mm, 28.08mm

Material                       Hardness

Steel Forging, 8620 59 - 63 Rc

Stock to be Removed Bore Length (Crank & Pin) Roundness Straightness (Crank) Straightness (Pin) Surface Finish

0.010mm – 0.015               18.11mm,  26.84mm 0.005mm 0.00127mm 0.00254mm 15 – 20 Ra

Model                                   Honing Work Stations Honing Tool Abrasive Coolant

HV-2000 2 B126-B20 (Crank & Pin) Oil

Bore Diameter (Crank & Pin)          Roundness (Crank & Pin) Surface Finish (Ra) Straightness

0.0127mm 0.0038mm 0.05 – 0.10 Ra (Crank) 0.20 (Pin) 0.00127mm (Crank) 0.00254 (Pin)

Bore Diameter (Crank & Pin) Roundness (Crank & Pin) Surface Finish (Ra) Straightness (Crank & Pin) Processing Time/Bore

0.005mm                                  <0.0038mm 3 Ra (Crank & Pin) <0.00127mm 15 seconds/bore average