SOP for Handling Punches and Dies (Tablet Tooling)

In short: This example SOP shows how a tablet department can control compression tooling (punches and dies) from purchase to disposal. It is for production, QA and engineering staff. Tooling is product-contact equipment, so GMP expects it to be fit for purpose, kept clean and maintained, with records. All limits and frequencies below are example in-house criteria to be set under your own quality system.

This is an illustrative template. Adapt every limit, frequency and annexure to your own tooling drawings, machines, products and quality system before use.

1. Objective

To describe how punches and dies used on tablet compression machines are ordered, received, checked, stored, issued, cleaned, polished and finally disposed of, so that they stay fit for use and do not harm tablet quality.

2. Regulatory basis

Punches and dies are equipment that touches the product, so the general equipment requirements apply:

• 21 CFR 211.67 requires equipment and utensils to be cleaned and maintained at appropriate intervals to prevent malfunction or contamination, under written procedures covering responsibility, schedules and methods, with records of cleaning and maintenance (see 21 CFR 211.180 and 211.182).
• EU GMP Part I, Chapter 3 (Premises and Equipment), paragraphs 3.34 to 3.36 expect equipment to be designed, located and maintained to suit its purpose, repair and maintenance not to endanger product quality, and equipment to be cleaned by detailed written procedures and stored clean and dry.
• EU GMP Part I, Chapter 5 (Production), paragraph 5.19 expects cross-contamination to be prevented through equipment design and effective, reproducible cleaning processes.

Neither document prescribes tooling-specific limits such as punch-height tolerance, polishing frequency or tooling life. Those are set by the site (from the tooling supplier’s specification, product experience and risk assessment) and are labelled “example in-house criterion” in this SOP.

3. Scope

This SOP applies to procurement, receipt, use, cleaning, maintenance, polishing and disposal of all punch and die sets (new and in use) and the related tools, the punch height checking kit and the punch polishing kit, in the tablet department.

4. Responsibility

5. Procedure

5.1 Ordering new punches and dies

New set or new supplier

1. The supplier prepares drawings for the upper punch, lower punch and die from the specification or from a sample set.
2. After the drawing is approved, the supplier sends a sample set (one upper punch, one lower punch, one die).
3. The department head approves the sample set after a trial on the machine.
4. The approved standard specification for the product’s tooling is recorded in the standard-specification annexure.
5. The purchase department raises the purchase order for the full set, authorised by the unit head, stating:
   • the number of sets needed for the machine. Example in-house criterion: a number of sets slightly above the number of stations to allow rotation, e.g. 31 sets for a 26-station machine, 37 for 32 stations, 60 for 55 stations;
   • the tooling type (for example D or B type);
   • the material of construction (for example high-carbon high-chromium steel or oil-hardened non-shrinkable steel);
   • engraving or laser marking on each punch: serial number, manufacturer’s short code, month and year of manufacture, punch size in mm, and any special features (embossing, break line, bevelled edge, chrome plating, groove for rubber cups).
6. On receipt, check the consignment against the specification and the sample set, and also check appearance and finish, damage (cracks or chips), working length (punch height), and fit of punches and dies on the machine. Record the observations in the receipt annexure.
7. The supplier should provide the drawing, a material-of-construction certificate and an inspection report with each set.

Repeat order from the same supplier

Place the order with the supplier who made the earlier set. Give one set to the supplier as a sample, and repeat the checks above.

5.2 Checking punches and dies

Check each punch and die individually against the standard specification, including the engraved details. If the supplier has provided all test documents, the set may be taken into use after in-house verification and QA approval.

Punches

Dies

Insert the upper and lower punch into each die to confirm they move freely.

Frequency (example in-house criterion). QA certifies a new punch set before first use. Visual checking is done after every batch and whenever the set is fitted to or removed from the machine.

5.3 Punch height checking

1. Take the set from the punch cabinet, clean the punches as per the cleaning SOP and arrange them in serial-number order.
2. Assemble the punch height checking equipment and clean its platform.
3. Place the calibrated standard hob on the platform below the dial, and set the dial indicator to zero. Recheck the zero against the standard hob.
4. Place each punch head down, tip up, and move the tip surface against the dial pointer. Note the minimum constant reading, which is the deepest point of the tip surface. On an embossed tip with a break line, set the pointer on a plain surface at the same location on every punch.
5. Record the variation in height of all punches in the punch height record.
6. Discard a punch whose working length is outside the in-house tolerance. Example in-house criterion: more than 0.003 inch from the standard height for round punches and more than 0.005 inch for other shapes.
7. Clean the platform, dismantle the equipment and return the parts to their drawer.

Frequency (example in-house criterion). Check at the earlier of the tablet-count interval below or one year.

One set means one upper punch, one lower punch and one die.

5.4 Polishing

Polish punches when a burr or claw appears on the tip, the tip turns black or rough, sticking or picking occurs, or the tablets look dull.

Polish dies when a ring forms inside the bore, the bore turns black, corrosion appears, or wear or drag is seen.

Polish as and when the above problems are seen, using the approved equipment and compounds. Remove all polishing residue by cleaning afterwards.

5.5 Issue and receipt of punch sets

Issue

1. Choose the set according to the product and machine, take it from the cabinet and clean it per the cleaning SOP.
2. Check the number of punches and dies and their suitability (tip, body, embossing).
3. Issue exactly the quantity needed for the machine, return spares to their drawer, and enter the issue in the punch stock card.
4. To spread wear evenly, rotate the sets. Example in-house criterion: rotate through the available sets at each product changeover or weekly, whichever is earlier (for example, first use stations 1 to 26, next time 6 to 31, and so on).

Receipt

1. After the batch or production plan is complete, dismantle punches and dies from the machine.
2. Clean as per SOP, check each piece, and store in the cabinet drawer or box with a thin film of food-grade oil of an approved specification.
3. Record the number received in the punch stock card.

5.6 Cleaning

• Clean punches and dies as per the separate cleaning SOP. For campaign manufacturing, example in-house criterion: clean the set after 5 batches or 3 days, whichever is earlier. Any campaign interval should be supported by your cleaning validation (see principles of cleaning validation).
• Dust caps: carry in a clean polybag to the wash area, immerse fully in water for about half an hour (scrub if needed), wash with filtered potable water, rinse with purified water and dry with filtered compressed air.

5.7 Storage and transport

Use a punch trolley to move tooling between storage and the compression room. Store punches in plastic sleeves in their cabinet. Calibrate the dial gauge and the standard hob every year (example in-house criterion); see the SOP for calibration.

5.8 Disposal

Dispose of a set when it becomes incomplete because too many pieces were rejected, or when a piece is unusable because of tip, head or body damage or corrosion.

1. Collect the defective punches and dies and incomplete sets.
2. Record details in the destruction record and prepare a scrap transfer note.
3. Deface the pieces with a grinder and transfer them to the scrap yard.
4. Do this only after approval by the head of production or QA and the unit head, with safety precautions.

Report any tooling damage found during use as a deviation (see handling of incidents and deviations), especially if broken pieces could have entered a batch.

6. Records and retention

Keep the height checking records, stock cards, certification records and destruction records as GMP records. Retain them for at least 1 year after the expiry date of the respective product batch (EU GMP Part I, Chapter 4, paragraph 4.11, which also requires 5 years after QP certification if longer; 21 CFR 211.180(a)), and longer if local law or the marketing authorisation requires.

7. Training and distribution

Operators and tool-room staff are trained on this SOP under the site’s training SOP. The SOP is distributed under the site’s document-control SOP.

8. Annexures

• Annexure I: Punch height checking record
• Annexure II: Punch stock card
• Annexure III: Punch and die destruction record
• Annexure IV: Standard specification
• Annexure V: Punch and die certification

9. Abbreviations

Frequently asked questions

Is there a regulatory limit for punch height variation? No limit is set in 21 CFR 211 or EU GMP Chapter 3 or 5. Tolerances come from the tooling standard and the supplier’s drawing, and the site sets its own limit as an in-house criterion.

How often should tooling be inspected? The regulations do not give a number. Many sites inspect visually after each batch and measure at set tablet-count intervals, justified by the product and tooling type.

Why do sticking and picking matter for GMP? They indicate tip wear or damage that can change tablet appearance, weight or content. Treat repeated occurrences through deviation and maintenance records.

References

1. US FDA, 21 CFR Part 211 (Current Good Manufacturing Practice for Finished Pharmaceuticals), sections 211.67, 211.180 and 211.182, as published in the eCFR (checked October 2026).
2. European Commission, EudraLex Volume 4, EU GMP Part I, Chapter 3: Premises and Equipment, paragraphs 3.34 to 3.36 (version of 13 August 2014, in operation from March 2015).
3. European Commission, EudraLex Volume 4, EU GMP Part I, Chapter 5: Production, paragraph 5.19 (version of 13 August 2014).
4. European Commission, EudraLex Volume 4, EU GMP Part I, Chapter 4: Documentation, paragraph 4.11 (record retention).