Technical guide

Cap torque test method for screw capping projects

Use this guide to prepare a better capping-machine brief where repeatable closure torque, opening force and bottle handling matter.

Why torque testing matters

A screw capping machine is not chosen only by cap diameter or advertised speed. The real test is whether the bottle, cap and filled pack can be tightened consistently without thread damage, cross-threading, leakage, deformation or poor opening experience for the end user.

Torque testing helps turn a vague requirement such as “tight enough” into a practical machinery brief. It gives the supplier a starting point for comparing a semi-automatic screw capper, an inline spindle capper, a chuck-style route or a capping setup with additional bottle support.

Samples and cap data

Prepare production bottle samples, filled-weight examples, closure samples and any liner or tamper-evident variants. Lightweight bottles, tall bottles, soft sidewalls and decorated containers may behave differently once they are full, labelled and travelling on a conveyor.

Record cap outside diameter, cap height, thread finish, bottle diameter, bottle height, closure material, liner type and any required orientation. If there are multiple caps or bottle sizes, group them by family so the changeover route can be assessed properly.

Practical test method

Start with hand-applied samples that represent acceptable production packs. Measure the removal torque across a useful sample size, then compare those values with leak performance, user opening experience and visual pack quality. The aim is not simply the highest number; it is a reliable range that protects the pack and suits production.

When automatic capping is tested, compare removal torque after the pack has travelled through the capping station, not just immediately after contact. Check for skewed caps, damaged threads, cap scuffing, bottle twist, label disturbance and any inconsistent feed behaviour.

What to send Lancing UK

Send the measured torque range, bottle and cap samples, target output, filling status, cap feeding preference and line layout. If torque is not yet known, send good and bad examples so the machinery discussion can begin from real packs rather than assumptions.

A stronger torque brief helps Lancing UK advise whether your project is better suited to a compact semi-automatic capper, an inline spindle capping machine, a cap feeding system or a wider line integration route.

Quick answers

Do all screw caps need the same torque?

No. Torque depends on the cap, bottle, liner, thread finish, product, fill weight and end-use requirements.

Can torque be checked before choosing a capper?

Yes. Testing hand-applied samples and supplied bottle/cap examples is often the best first step.

Does higher torque always mean a better seal?

Not always. Excessive torque can damage threads, deform bottles or make packs difficult to open.

Related pages

Useful next pages

Use these pages to connect the guide with capping machine specifications, cap feeding and quote preparation.

Spindle Capping Machines UKCompare UK spindle capping machines for screw caps, pumps and trigger sprayers. Semi-automatic, compact and inline automatic capper rou.
Screw Capping Machines UKUK screw capping machines for bottles, jars, pumps, trigger sprayers and threaded caps. Compare semi-automatic, compact and inline auto.
Cap Tightening Machines UKCap tightening machines UK for screw caps, pumps and trigger sprayers. Compare semi-automatic torque heads, compact cappers and automat.
How to Specify Cap TorqueGuide to specifying cap torque for screw capping machines, including bottle samples, closure materials, liners and acceptance limits.

Ready to shortlist?

Send the bottle, cap and target output.

Lancing UK will help identify the most suitable capping route for your product, closure and production target.

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