Technical Advices - SUGINO MACHINE

» What is Superoll processing?

» Processing conditions

» How to adjust and set tool diameter (SH/SB series)

» Variations in internal diameter

» Effects of Superoll processing

» Replacing consumable parts

For internal surface processing with the Sugino SUPEROLL the tool diameter is set at a larger value than the diameter of the hole before processing.

Either the tool (or the workpiece) is rotated and fed for the burnishing operation.
This difference between the tool diameter and that of the preprocessed hole is termed the "burnishing value".
Relations between the burnishing value, surface roughness and variations in internal diameter for various types of metals are shown in the diagram below.

Generally, surface roughness improves as the burnishing value increases. For S45C (JIS) material the best surface finish is obtained with a burnishing value of .00158" [0.04mm] ~ .00275" [0.07mm].

On the other hand, surface roughness will deteriorate at a higher burnishing value, which is attributed to the fact that roller pressure increases at higher burnishing values causing surface peeling. Although the optimum burnishing value will differ depending on the material and wall thickness a value of about 3 ~ 5 times the surface roughness before burnishing will result in the best finished surface. With SUPEROLL processing the internal diameter will increase simultaneously with improvement in the surface finish. After SUPEROLL processing, the internal diameter will not permanently expand to the exact set tool diameter. Elasticity of the material will rebound within the diameter of the hole and it will controllably decrease dimensionally after making an expanding pass on the work piece and removing the tool.

Variations in the internal diameter will differ according to the work piece material. With nonferrous materials such as aluminum or bronze the degree of variations in the internal diameter increases almost linearly as the burnishing value increases. With nonferrous materials the sizing (dimensional specification) function is high, enabling finished measurement dispersions of less than .000394" [0.01mm] to be attained as against dispersions of .00118" [0.03mm] in the internal diameter before processing.

For steel and cast iron the burnishing value is within the range of .00158" [0.04mm] ~ .00275" [0.07mm]. There are almost no variations with these materials internal diameters so the sizing function is not as evident as in the case of aluminum or bronze. For steel and cast iron 60 ~ 70% of the dispersions in measurement present in the preprocess work are corrected.

Relations between burnishing value surface roughness and
variations in internal diameter for each material

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