Contact Sales on +44 (0)1472 240940
Berlin Packaging expands its presence in EMEA with the acquisition of BlueSky.
Contact Sales on +44 (0)1472 240940
Berlin Packaging expands its presence in EMEA with the acquisition of BlueSky.
A cap may look secure. A pump may appear to fit. A sprayer may feel tight by hand. But if the torque is not right, the finished pack can still leak, loosen, crack, fail a seal or become difficult for the customer to open.
For brand owners, contract fillers and manufacturers, correct torque application is an important part of packaging quality.
It affects product protection, customer experience, production efficiency and the reliability of the finished pack.
Whether you are applying screw caps, pumps, sprayers, child-resistant closures, tamper-evident caps or lined closures, torque should be considered before full production begins.
Closure torque is the rotational force used to apply or remove a closure from a bottle, jar or container.
In packaging, torque is usually measured in inch-pounds or newton centimetres, depending on the equipment and production setup.
There are two main torque measurements to understand:
| Torque type | What it means |
|---|---|
| Application torque | The force used to apply the closure to the container |
| Removal torque | The force needed to remove the closure after it has been applied |
Both matter.
Application torque affects how securely the closure is fitted during production. Removal torque affects how the customer experiences the pack when opening it.
A closure that is too loose may leak. A closure that is too tight may damage the container or frustrate the customer.
Correct torque helps the closure do its job.
The closure needs to seal the product, protect the contents and remain secure through filling, handling, storage, transport and customer use.
If torque is too low, the pack may experience:
If torque is too high, the pack may experience:
The aim is to find the correct torque window: secure enough to protect the product, but not so tight that the pack becomes damaged or difficult to use.
Application torque and removal torque are related, but they are not the same.
Application torque is the force applied when the closure is fitted to the container during production.
Removal torque is the force required to open the closure later.
Removal torque can change after application. This can happen because of material relaxation, liner compression, product interaction, temperature changes, storage time and transport conditions.
For example, a closure may be applied correctly on the filling line, but after storage or transit the removal torque may be higher or lower than expected.
That is why torque testing should not only happen at the point of application. It should also be checked after storage, conditioning and transport where relevant.
Torque is influenced by more than the capping machine setting.
Several packaging and production factors can affect how a closure performs.
These include:
This is why there is no single universal torque setting that works for every closure and container.
A 28mm cap on a PET bottle may require a different approach from the same size cap on a glass bottle. A lined closure may behave differently from an unlined closure. A child-resistant closure may need additional validation to confirm both safety and usability.
One of the most common reasons to control torque is leakage prevention.
If the closure is under-tightened, the seal may not be secure enough. This can allow product to leak during transport, storage or use.
Leakage is especially problematic for:
However, over-tightening is not the answer.
Too much torque can damage threads, distort the container neck, compromise the liner or make the closure difficult to remove.
The correct torque setting is about balance, not simply making the closure as tight as possible.
Torque affects the customer’s first interaction with the product.
If a cap is too loose, the customer may question whether the pack has leaked or been opened. If it is too tight, the customer may struggle to use the product.
This is especially important for:
A closure should feel secure, but still usable.
For brands, this is part of perceived quality. A product can be well formulated and well designed, but a poor opening experience can still damage the impression of the pack.
Torque recommendations vary depending on the closure, container material, liner, product and production process.
The table below should be treated as a starting point only, not a universal specification. Always check supplier guidance, machinery settings and product-specific testing requirements before production.
| Recommended Application Torque Values | ||
| Rigid Caps on Plastic Containers | Rigid Caps on Glass Containers | |
| Size | Torque | Torque |
| (mm) | (Inch/Lbs) | (Inch/Lbs) |
| 18 | 7 – 10 | 8 – 12 |
| 20 | 8 – 12 | 10 – 14 |
| 22 | 8 – 12 | 10 – 16 |
| 24 | 9 – 15 | 12 – 16 |
| 28 | 10 – 18 | 14 – 18 |
| 30 | 12 – 20 | 16 – 24 |
| 33 | 12 – 21 | 18 – 27 |
| 38 | 15 – 25 | 20 – 30 |
| 43 | 17 – 27 | 22 – 36 |
| 48 | 19 – 30 | 24 – 36 |
| 53 | 21 – 36 | 25 – 40 |
| 58 | 23 – 40 | 28 – 45 |
| 63 | 25 – 43 | 30 – 45 |
| 66 | 26 – 45 | 30 – 45 |
| 70 | 28 – 50 | 35 – 50 |
| 89 | 36 – 60 | 45 – 60 |
| 120 | 48 – 70 | 60 – 70 |
These values are useful for initial guidance, but they should not replace testing with the actual closure, container, liner and product.
Torque testing checks whether closures are being applied consistently and correctly.
It helps confirm that the closure is neither too loose nor too tight.
Torque testing can help identify:
For production teams, torque testing is a practical quality control step. It helps spot issues before they become filled stock, customer complaints or rejected batches.
Torque testing should be carried out using calibrated equipment.
A torque tester measures the force required to apply or remove a closure. Testing can be manual or automated depending on the production setup.
A practical testing process may include:
For products where leakage, child resistance, tamper evidence or transport durability is critical, torque testing should be part of a wider pack validation process.
Torque validation means confirming that the selected torque setting works for the complete pack.
This is more than checking that a cap can be tightened.
Validation should consider:
A closure may pass an initial torque test but still fail later if the pack is exposed to heat, vibration, pressure changes or product interaction.
That is why validation should be based on real conditions wherever possible.
For contract fillers, this is especially important because the filling process, capping equipment and customer specification must all align.
Lined closures and induction seals need particular attention.
If the torque is too low, the liner or seal may not make proper contact with the container neck. If the torque is too high, the liner may be over-compressed or the closure may become difficult to remove.
For induction-sealed packs, torque can affect how the seal sits before induction and how the closure behaves after sealing.
Buyers and fillers should check:
The closure, liner and container should be specified together.
Child-resistant and tamper-evident closures can be more sensitive to torque settings than simple screw caps.
If the torque is wrong, the closure may not perform as intended.
For child-resistant closures, incorrect torque may affect opening performance, user accessibility or compliance testing.
For tamper-evident closures, incorrect torque may affect band engagement, first-opening evidence or seal integrity.
Brands and fillers should consider:
These closures should always be tested as part of the complete pack.
Torque issues can show up in different ways.
| Problem | Possible cause |
|---|---|
| Cap leaks | Torque too low, liner issue, poor neck fit or product residue |
| Cap is difficult to open | Torque too high, thread issue, liner compression or storage effect |
| Closure cracks | Over-tightening, material mismatch or unsuitable cap design |
| Bottle neck deforms | Excessive torque, weak neck finish or material issue |
| Tamper band does not engage | Incorrect closure fit, torque issue or application problem |
| Induction seal fails | Closure, liner, torque or sealing process issue |
| Removal torque changes over time | Material relaxation, storage conditions or liner behaviour |
The solution depends on the cause. Simply increasing or reducing torque without understanding the issue can create a different problem.
Before full production, brands and fillers should confirm:
The right torque setting should be part of the pack specification, not decided informally on the line.
BlueSky supplies bottles, jars, caps, closures, pumps and sprayers for personal care, healthcare, home care, food, beverage, animal health and contract filling applications.
The team can support with:
BlueSky can help customers identify suitable packaging components and provide guidance where available.
Final torque settings and validation should always be confirmed by the brand owner, filler or manufacturer using the actual components, product and production process.
Correct torque application helps protect product quality, reduce leakage risk and improve the customer experience.
Whether you are specifying screw caps, tamper-evident closures, child-resistant closures, pumps or sprayers, BlueSky can help you choose packaging components that work together.
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Speak to the BlueSky team →
Our expert team is ready to assist you with your packaging needs.
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