This is a holder made of Super Invar.

Super Invar is a material that specializes in even lower thermal expansion near room temperature
compared to regular Invar. It is an alloy with a high amount of nickel and cobalt mixed with iron,
making the material cost very high. It is also called super invariable iron, indicating its low thermal expansion.
It is used for special applications in precision machine parts, and this holder is one of them.

The processing surface of Invar tends to leave cutter marks compared to steel materials,
but it is possible to process shapes similar to steel.
However, it is a difficult material to handle,
so processing Invar includes various know-how from tool selection to processing conditions.
If you have any inquiries about processing difficult materials, please feel free to contact us.