Look up the mounting-hole diameter, screw thread and Torx wrench size for APKT, APMT and SEHT milling inserts — then confirm which cutter body pocket takes that insert.
1 Find your insertType the full designation, e.g. APKT1604PDER or APMT1135.
2 Read the rowHole diameter, screw thread, screw length and wrench size.
3 Confirm the pocketMatch the cutter body series before ordering.
Full reference table — all insert classes (no search needed)
Insert class
Common designations
Mounting hole
Screw thread
Screw length
Torx wrench
Matching cutter body
Hole diameters from published insert dimension tables. Screw threads cross-checked against currently listed replacement screws and the insert mounting-hole diameter.
Three ways people order the wrong screw
Sizing by the size code alone. APKT1135 and APKT1604 share the APKT prefix but use different hole diameters (2.80 mm vs 4.50 mm) and different screws. The size digits are not the screw size.
Treating APKT and APMT as interchangeable. K and M are different tolerance classes. The insert may seat badly in a pocket cut for the other class.
Mixing up screw length. The same M4 thread is sold in 8 mm and 9 mm lengths with a D5.7 head. Too long and the screw bottoms out before the insert seats.
Before you order — 5-point self check
Write the complete designation. Include radius digits and the suffix (PDER, PDFR-MA, AFTN). APKT160408 is not APKT1604.
Measure the mounting hole with a pin gauge or calipers. 2.80 mm points to M2.5; 4.50 mm points to M4.
Compare the old screw. Measure thread diameter, overall length and head diameter against the table.
Check the pocket, not just the insert. Seat the insert in the body by hand — it should sit flush with no rock before you torque anything.
Torque to the insert supplier value. Over-tightening cracks the insert; under-tightening lets it move and breaks the edge.