I have a face(spider) mill that uses SPMT inserts. I need to buy inserts but there are so many different types. I mainly will be milling aluminum, cast iron, mild steel and plastic. Whatever inserts that are in there work well, but there isn't any marking on them and I bought the mill used. Can anybody suggest some inserts that are responably priced?

What company made the cutter, and what is the I.C. (inscribed circle) size fo the SPMT insert needed?

The cutter is made by Iscar, I don't know what the IC number is.

try E-bay, but you'll need the ic, thickness and you'll need to know what chip breaker you want

You should be able to get some nomenclature off the cutter body. Those letters and numbers will tell exactly which inserts you need in terms of I.C and thickness. You will probably have to get Iscar inserts because more & more, the cutter manufacturer uses proprietary inserts for milling cutters.

An SPMT insert from Iscar may not be the same size as one from Kennametal. I know this is a problem with APKT inserts.