K390-551
A direct replacement for the Summa 390-551, with no holder modification needed. Single edge drag blade for kiss cutting on Cutworx Apex, Esko, Gerber / MCT, Summa, and Zund flatbed cutting systems.
Sold individually.
Direct OEM replacement
The K390-551 is a direct replacement for the Summa 390-551 blade. Same form, same fit, same geometry. Compatible with the Summa tangential knife holder 395-322. No holder modification needed before you put it to work.
What is kiss cut cutting?
Kiss cutting means the blade cuts through the face material (the vinyl, film, or label stock) without cutting through the liner underneath. The finished piece peels cleanly from the sheet. This blade is built specifically for kiss cut work. It is not a through-cut blade.
Fine grain tungsten carbide
The K390-551 is made from fine grain tungsten carbide. Carbide holds an edge significantly longer than steel in demanding production environments. On a machine running vinyl and adhesive-backed media all day, that means fewer blade changes, more consistent cut quality, and less downtime between runs.
Common questions
How do I know this fits my machine?
The K390-551 replaces the Summa 390-551 and is compatible with the Summa tangential knife holder 395-322. If you are running a Cutworx Apex, Esko, Gerber / MCT, Summa, or Zund cutting system and need to confirm fit before ordering, contact us. We will tell you exactly what you need.
What materials does it cut?
This blade is designed for kiss cutting self-adhesive vinyl, masking film, transfer paper, polyester, polycarbonate, window prep vinyl, magnetic media, and 3M VHB. For materials outside this list, or if you are cutting thicker stock and questioning whether this is the right geometry, reach out before you order.
What do the cutting angle and wedge angle mean?
The K390-551 features a 35 degree cutting angle and a 40 degree wedge angle. The 35 degree cutting angle helps the blade track smoothly through the material with reduced drag, while the 40 degree wedge angle provides the ideal balance of sharpness and edge durability. Together, they deliver clean cuts, excellent detail reproduction, and consistent liner protection in demanding production environments.
How do I know when to replace it?
Watch cut quality, not a clock. If the blade is dragging through material instead of slicing cleanly, tearing at corners, or leaving the liner attached when it should peel, it is time to swap it out. Carbide holds an edge longer than steel, but it does not last forever, especially on abrasive media or high-volume runs.
Getting the most from your cutting table
A fresh blade is a good start. But if you are going through blades faster than expected, or cut quality has become inconsistent, the blade is rarely the whole story. Cut depth, speed, pressure, and machine condition all affect how long a blade lasts and how clean it cuts.
It is worth asking: When was your machine last serviced? Are your parameters dialed in for this material? Is this the right blade geometry for what you are cutting? Could your operators use time with someone who runs these machines every day?
Flatbed Tools offers machine service, preventive maintenance, operator training, and workflow consulting. If something is not cutting right, reach out. We have probably seen it before.