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SOP for Die and Punch for Compression Machine

To lay down a procedure for the procurement, inspection, storage, utilization, polishing, stock update and destruction of Dies and punches.

This standard operating procedure shall be applicable to the tabletting section.

The tabletting supervisor is responsible for issuing, storage and utilization of punches and dies.
Q.A inspector is responsible for the inspection of the Dies and Punches.

Die and Punches are tablet tools for control of weight, thickness, hardness and appearance.


  • The user dept. will raise indent as per requirement and indent should be authorized by dept. head and GM. Following should be mentioned in indent: punch size, embossing if any, MOC, concavity and supplier. If it is a repeat order then previous drawing no. should be mentioned.
  • Indent sent to purchase dept. for purchases order generation. Purchase dept. will forward the PO to the supplier.
  • Supplier will send drawing for approval. Drawing to be checked and approved and then it is to be informed to the supplier for go ahead.
  • Suppliers will send the entire set along with inspection record, MOC certificate.

  • Cross check the quantities as per delivery documents of tooling supplier and also for any physical damage to the tooling.
  • Use magnifying glass and inspect the punch tip face closely for any damage or poor finish.
  • Use magnifying glass and inspect punch head for any damage.
  • Check whether the inspection report of tooling supplier is within the limit as per our specification or not.
  • Individually measure all dimensions and cross check with tooling supplier inspection report. If tooling supplier inspection report does not match with our inspection report then our report will be final for deciding acceptance or rejection of punch set.
  • Measure the tip size with micrometer.
  • Measure the Barrel diameter with a Micrometer.

  • Overall length: measure with the vernier calipers from the head to the tip
  • Working length: measure with vernier calipers the tip head.
  • Record the reading in Annexure V.

  • Die height: measure the die height using the micrometer.
  • Die outer diameter: measure with the micrometer.
  • Die inner diameter: measure with the micrometer.
  • Record the detail in annexure IV.
  • Fitting: check whether the punches are fitting properly in the dies.

  • Store dies punch in die punch cabinet after applying food grade oil.

  • Die punch to be utilized in rotation. If we have 25 set and we are using for 16-station machine then first time 1 to 16, second time 2 to 17 like this so that wear and tear will be uniform in all the punches.
  • Record the details of issuance and return in annexure 1 (die punch issuance record). Punch number which is issued to be written in remarks column of annexure 1.
  • Clean the die punch with alcohol before use.
  • After use clean the die punch with diesel and apply food grade oil and store in storage cabinet.
  • Record the die punch utilization in annexure II.

  • Barrel: The barrel needs to be polished only when found corroded or discolored.
  • Fix the head and half of the barrel on the chuck.
  • Polish the barrel with Scotch Brite Sheet or 600 grit emery sheet while rotation.
  • Excessive polishing of the barrel reduces the barrel diameter. Take necessary care.
  • Tip face: shape the felt bobs as per the punch tip concavity.
  • Fix the bob in the polishing motor and apply the correct grade compound on the punch.
  • Start polishing the machine and gently press the punch face on the bobs and this result in good face finish.
  • For embossed punches nylon brushes are preferred.
  • Polishing the punches after every 50 million tablet is compressed or there is sticking problem in the tablet and record the details in remarks column of annexure II.

  • Destruction of die and punches to be done in the following cases.
  1. If punch tip is damaged.
  2. If there is continuous sticking even after polishing.
  3. Burr formation in the die.
  4. If punch head is damaged.
  5. After 500 million tablets is compressed.
  • Take authorization in annexure III before destruction.
  • Fill die punch destruction record and die punch stock statement annexure IV before punch destruction.

Die punch file
  • Die punch file consists of following document.
  1. Purchase order copy.
  2. Approved drawing of punch set.
  3. Inspection report from the supplier.
  4. MOC certificate from the supplier.
  5. Annexure II die punch utilization.
  6. Annexure III authorization of die punches destruction.
  7. Annexure IV die punch stock statement.
  8. Annexure V.
  9. Annexure VI die inspection record.

GM : General Manager
MOC : Material of Construction
PO : Purchase Order

Annexure I : Die punch issue & return register.
Annexure II : Die punch utilization.
Annexure III : Authorization of die punches destruction.
Annexure IV : Die punch stock statements.
Annexure V : Punch inspection records.
Annexure VI : Die inspection records


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