Machining with a lathe has unique challenges.

Inconsistencies in surface roughness

Shortened life for cutting tips

Adding a grinding process with another machine

Superoll™ is the answer.

ROLLER BURNISHING

What is Superoll?

Superoll is a full line of roller burnishing tools that create smoother finishes through compressing the surface - without removing material.

LEARN MORE

Explore example case studies

See Example Cases

Quality and Precision

These hardened and highly polished tools integrate into machining centers to eliminate secondary processes such as grinding and honing, without removing any material.

A Mirror-Like Finish

Ideal for processing with shorter cycle times to improve productivity and reduce costs.

What is Surface Roughness? How is it Calculated?

Surface roughness is the geometrical fine irregularities on the surface of an object. In turning, it refers to the height of the peaks and valleys formed by transferring the tip shape of the cutting.

How to calculate theoretical surface roughness [Rz]

F: Feed amount per rotation (mm/rev)
R: Nose R size of cutting tip (mm)

However, does the actual surface roughness match the theoretical roughness in your production site?

Let's explore reasons why they may not match

Why the actual surface roughness does not match the theoretical roughness:

REASON 1: Build-up edge deteriorates the surface roughness.

Machining under inappropriate conditions causes built-up edges at the tip of the cutting tip.

As a result, the machined surface does not have a regular shape, and deviates from the theoretical shape.

Surface property measurement data — machined by
a cutting tip with build-up edge.

"Build-up edge" is the phenomena in which a tiny part of the work piece adheres to the cutting tip edge during cutting, and changes the shape of cutting edge. The slower the feed rate, the better the surface roughness, but the more likely it is that adhesion will occur. Thus, machining with high speed rotation will be required.

Why the actual surface roughness does not match the theoretical roughness:

REASON 1: Build-up edge deteriorates the surface roughness.

Machining Conditions

Work piece: Φ30 SCM440

Cutting tip: Carbide / Nose R 0.4

Coolant: Not used

Peripheral speed: 50 -250m/min

Feed: 0.05 - 0.3mm/rev

Cutting amount: 0.4mm *Fixed

Why the actual surface roughness does not match the theoretical roughness:

REASON 2: Wear of the cutting tip.

Surface roughness gradually gets worse due to the wear of cutting tip.

Surface Roughness After Machining Data Chart

Therefore, when aiming for Rz 3.2 in mass production — assuming that it will gradually deteriorate — appropriate feed rate will be 0.07 mm/rev, and then required peripheral speed will be 450 mm/min (4,775 rpm).

However, if the cutting speed (peripheral speed) is faster, the tool life will be shortened significantly due to the increase in cutting temperature. In addition, slowing the feed rate increases flank wear, which leads to a shorter tool life.

Surface Roughness Calculator →

Enter your values in the calculator below to determine Rz and Ra. NOTE: As a guideline or simple conversion - though with less accuracy - we convert Rz into Ra by dividing into 4.

Challenges and Solutions

Explore real-world examples of how Superoll can simplify and improve your process.

Case Example One:

Automate Unstable Works

Problem

The workpiece is too long for high-speed machining. The vibrations at high speed resulted in an uneven finish and surface roughness.

Conventional Way

Achieved dimensional accuracy only by machining at a low speed. But sandpaper hand-finishing was required to meet surface roughness specifications, and uniformity is lacking as hand-finishing varies by worker.

With Superoll

No hazardous waste. The process is fully automated which results in a uniform finish every time. Stable surface roughness. Reduced cycle time.

Case Example Two:

Reduction of cutting tip replacement frequency

Problem

Problem: The cutting tip life was significantly short due to surface roughness

Conventional Way

The cutting tip needed to be replaced frequently due to the rough surface texture.

With Superoll

Because the Superoll uses compression instead of cutting, the tool life is extended up to four times longer than conventional cutting tips. This saves time and money.

Case Example Three:

Optimizing the Machining Conditions for Crankshafts

Image of Superoll Machining Burnishing Crank Shaft

Problem

A low rotation speed is needed to maintain balance during the machining process.

Conventional Way

The necessary low rotation speed required a separate grinding step and the purchase of an expensive secondary machine.

With Superoll

Surface stability is achieved without the use of a secondary machine.

Case Example Four:

Integrate the Machining and Grinding Process Together

Problem

Low speed machining leads to edge buildup. Edge buildup leads to scratches.

Conventional Way

Required visual inspection for all parts.

With Superoll

Allows the machining to be done at high peripheral speed with a fast feed. This creates no edge buildup. No edge buildup = no scratches = no need for inspection. Saving time and labor costs.

Comparing Conventional Methods with Using Superoll in your Lathe

Rough Machining + Dimensional Finish + Surface Finish

Lathe Machining the Conventional Way

Input your text here! The text element is intended for longform copy that could potentially include multiple paragraphs.