Round bar machining techniques
The SuperFlex range includes polyurethane solid rod. This material can be machined with ease, and is available in 70, 80, 90 & 95 Shore "A" Hardness.
SuperFlex solid rod is available in production colours of dark blue or red.
These helpful hints will ensure safe, accurate maching of polyurethane rod.
- Tool: Parting tool must be in the form of a razor sharp knife blade. The machining tool should have a 30 degree rake on the leading or top edge. Use of light oil will assist deep parting off.
- Surface: 500 ft/min e.g. - 2000 RPM on 1" bar.
- Length Ratio:Simplest to machine with 2:1 diameter to length ratio, e.g., 2" solid rod projects 4" out of chuck. (The poly rod will move away from the tool if any lower).
- Travelling Steady:Don’t use traveling steady when machining long tubular lengths. The friction created where the steady comes into contact with the rod, will melt the polyurethane.
- Mandrel:When machining outside diameter on long tubular parts, machine on a "Mandrel".
- Drilling:When drilling, force drill into rod to create required internal diameter, then allow drill to dwell for a smooth finish. The polyurethane material will actually melt to size.
It is also possible to grind polyurethane with great accuracy. A grinding attachment can be mounted on the toolpost of a lathe, whilst the pu is turned.
Special Note:When working with 70 Duro, for best results and for ease of machining, place rod to be worked on, into the freezer section of a refrigerator the night before.
- When machining any polyurethane component DO NOT INHALE any vapour or smoke which could be created.
- Always wear protective clothing and glasses.