4mm MGMN Grooving Holder suitable to MGMN400 pack of 1 40mm facemill cutter you can use any ISO

you can use any ISO inserts of Hitachi Brand Insert RDMT10T3 MOTN

or outside diameter of an object

APKT11T308 ZCCCT carbide insert can fit into the same cutter for this

but 80 mm and 100 mm Cutters are usually standard in this range

If you order one quantity

4mm MGMN Grooving Holder suitable to MGMN400 pack of 1 40mm facemill cutter you can use any ISO4MM MGMN Grooving Holder suitable for MGMN400 MRMN400 Grooving holders are used for parting and grooving in a turning machine. 4 mm grooving holder suitable for the KORLOY profile of the insert, it can fit any insert named MGMN 2 mm T max is the maximum grooving capacity of the holder. If the grooving capacity is 20 mm, it means it can part a round bar by up to 40 mm.