In the automotive and motorcycle manufacturing industries, the machining of connecting rod bores is a critical process that directly impacts engine performance and lifespan. When the material involves hardened steel (such as SCM420H at HRC60), achieving strict geometric tolerances and superior surface finishes with a very small machining allowance becomes a significant technical challenge.
Recently, MORE SUPER HARD successfully delivered a high-performance tooling solution for a client struggling with exactly this challenge. Below is a detailed breakdown of how our Custom Electroplated CBN Honing Reamer optimized their production line.
1. Project Overview & Technical Requirements
The client required the final precision finishing of a motorcycle (two-wheeler) connecting rod hole. The preceding operation utilized CBN inserts, leaving an extremely tight allowance for the final honing process.
Detailed Application Parameters:
Workpiece: Motorcycle / Two-Wheeler Connecting Rod
Material: SCM420H (Hardened Alloy Steel)
Material Hardness: HRC 60
Machine Tool: Vertical Machining Center (VMC) with BT40 Spindle
Machine Accuracy: 5 μm
Target Processing Part: Connecting Rod Bore / Hole
Previous Operation Size: Pre-machined with CBN inserts to Ø 32.965 – 32.975 mm
Honing Allowance: 0.01 mm – 0.02 mm
Final Target Dimension: Ø 32.985 mm
Strict Quality Standards:
Surface Finish: Ra ≤ 0.8 μm
Taper Tolerance: ≤ 5 μm
Out-of-roundness (Ovality): ≤ 0.012 mm
2. The MORE SUPER HARD Solution: Custom Electroplated CBN Honing Reamer
Based on an in-depth analysis of the client's strict working conditions and micro-allowance requirements, traditional reaming or grinding tools were insufficient. To meet this challenge, MORE SUPER HARD engineered a Customized Electroplated CBN Honing Reamer, designed to deliver uncompromising precision.
Every detail, from the customized structural design and core material selection to the final adaptive commissioning, fully demonstrates our brand's technical superiority in superhard cutting tools.
Key Product Highlights:
Seamless Machine Integration (BT40 Design):
To avoid any runout issues, we precisely matched the tool's shank design to the customer's VMC-BT40 spindle. This achieves a seamless connection between the tool and the equipment, effectively eliminating the impact of clamping errors on machining accuracy right from the source.
Advanced Proprietary Electroplating Technology:
The core cutter body is coated with premium-grade Cubic Boron Nitride (CBN) abrasives. Relying on MORE SUPER HARD's independently developed and advanced electroplating process, we ensure a remarkably tight and firm bond between the CBN abrasive and the cutter body. This provides the ultra-high hardness and exceptional wear resistance necessary to effortlessly machine the HRC60 SCM420H material.
Extreme 5μm Tool Precision (The Closed-Loop Advantage):
Most crucially, the intrinsic precision of our customized honing reamer is strictly controlled to be within 5 μm. This forms a perfect match with the 5 μm precision of the customer's VMC. By building this integrated "Machine Tool - Cutting Tool" precision closed loop, we provided the core guarantee for stably achieving the tight taper (≤ 5 μm) and ovality (≤ 0.012 mm) requirements.
3. Results and Customer Value
By upgrading to the MORE SUPER HARD Electroplated CBN Honing Reamer, the client successfully achieved the final dimension of Ø 32.985 mm with a flawless Ra 0.8 surface finish.
Beyond just meeting the geometric tolerances, our CBN honing solution delivered two major business benefits:
Extended Tool Life: The superior wear resistance of our electroplated CBN abrasives drastically reduced tool wear during the high-hardness machining process.
Reduced Machining Costs: The extended lifespan and single-pass finishing capability significantly lowered the customer's unit machining cost, maximizing their overall Return on Investment (ROI).
Are you facing challenges with high-hardness bore finishing or struggling to maintain tight geometric tolerances?
At MORE SUPER HARD, we specialize in designing and manufacturing custom CBN and PCD tooling solutions tailored to your exact spindle and material requirements.
Contact our engineering team today to discover how our high-precision honing reamers can optimize your production efficiency.
