Buyer guide

Screw Capper Torque Guide

Understand the practical torque questions to answer before choosing a screw capping machine.

Screw capping machine supplied by Lancing UK

How to choose the right route

Torque is one of the main reasons to use a screw capping machine. Too little torque can lead to loose caps and leakage risk, while too much torque can damage threads, distort caps or make the pack difficult to open.

The correct setting depends on closure design, neck finish, liner, product risk and customer requirements. A trial with real samples is often the safest way to confirm the route.

Confirm cap diameter and closure type.
Check whether the cap has a liner or tamper feature.
Define acceptable opening and closing torque range.
Use representative bottles and caps for trials.

Planning points

What to check before shortlisting

Bottle and cap fit

Confirm the bottle neck finish, cap thread, closure height and required finished-pack result.

Real output target

Check target bottles per minute or bottles per hour and whether the operator can sustain the workflow.

Integration needs

Decide whether the capper is standalone or needs to connect to filling, labelling or conveyors.

FAQs

Common questions

What information is needed for a quotation?

Send bottle dimensions, cap type, cap diameter, target output, product type, photographs and whether cap feeding or line integration is required.

Can Lancing UK review samples?

Yes. Representative bottles and caps help confirm grip, torque, cap presentation and changeover requirements.

Can the machine be linked into a filling line?

Many screw capping machines can be supplied as standalone equipment or planned as part of a filling, capping, labelling and conveyor line.

Need a screw capper recommendation?

Send photos, samples or dimensions and Lancing UK will help shortlist the most suitable machinery route.

Send an enquiry Call 01494 623015

Test method

Build a repeatable screw-cap torque test around the finished pack.

A numeric machine setting is not a universal closure specification. The target must come from the approved bottle, cap, liner, product and quality requirement. The test method should distinguish the setting used to apply the cap from the result measured on the finished pack.

1. Define the pack and condition

Record bottle and cap references, supplier batch, liner or wad, fill level or test weight, product around the neck, temperature where relevant and the time between application and measurement. These conditions can change removal behaviour.

2. Confirm thread engagement before measuring

Inspect the thread start, cap angle and final cap height. Reject cross-threaded, cocked or visibly damaged samples from the torque study and investigate the process cause; otherwise the number can hide a poor closure.

3. Record application and removal separately

Document the machine head, chuck or spindle setup and the capping setting used. Then record the measurement device, fixture, direction, rate and elapsed time used for removal testing. Use one agreed procedure consistently rather than comparing results from different methods.

4. Add closure-integrity checks

Where the pack requires them, inspect liner compression, tamper-feature condition, cap height, leakage and the consumer opening experience. A cap can meet torque while failing another critical pack requirement.

5. Link the result to a timed run

Confirm that the accepted result is maintained during normal bottle flow, cap replenishment and line stops. Record outliers, cross-threading, cap slip and bottle movement so tooling or handling causes are not treated as random torque variation.

Use a controlled record: the bottle-cap torque-test checklist can be used with the torque setup support and sample trial route.

Torque FAQ

Questions about screw-cap torque control.

Is application torque the same as removal torque?

No. The torque applied by the machine and the torque measured when opening are related but not identical. Time, liner compression, product, temperature and the test method can change the removal result.

Can Lancing give one torque number for every cap size?

No. The accepted value belongs to the specific bottle, closure, liner, product and quality requirement. It should be agreed and validated with the production pack.

Why should cap height be checked with torque?

A cross-threaded or partially engaged cap can produce a misleading torque result. Height and visual engagement help confirm that the closure reached the correct position.

How often should torque be checked?

The production quality plan should define frequency. Checks are particularly useful after start-up, changeover, tooling adjustment, cap-batch change or a capping fault.

What should be recorded during a torque trial?

Record the pack, cap batch, liner, filled condition, machine and tooling, settings, line speed, sample timing, measurement device/method and the accepted range.

Can torque alone prove closure integrity?

No. Depending on the pack, liner condition, cap height, thread engagement, leakage, tamper feature and opening experience may also be required.

Closure acceptance

Separate application torque, removal torque and closure integrity.

A cap can feel tight and still be cross-threaded, sitting high, damaging the liner or creating an opening result that changes after storage. Torque is useful only when it is tied to the complete finished-pack requirement and a repeatable test method.

Measurement or inspection	What it indicates	Variables that can distort the result	What to record
Application setting	The machine setting or clutch condition used while the cap is tightened.	Chuck grip, cap surface, bottle rotation, head speed, spindle pressure and thread start.	Machine, tooling, format settings, operator or feed method and the sample identity.
Immediate removal torque	The force required to open the pack soon after application.	Delay before testing, tester method, temperature, operator technique and cap or liner recovery.	Time from capping to test, equipment used and result for each labelled sample.
Conditioned removal torque	How the closure behaves after the agreed storage or conditioning period.	Product contact, temperature, fill condition, liner compression, neck finish and material relaxation.	Conditioning duration, environment, pack orientation and any leakage or deformation.
Cap height and seating	Whether the closure has followed the thread and reached the intended final position.	Cross-threading, damaged threads, tilted placement, liner thickness and tamper-band engagement.	Reference measurement or accepted visual sample from several points in the run.
Liner and neck inspection	Whether the sealing surfaces remain undamaged and correctly compressed.	Product contamination, burrs, neck-finish variation, overtightening and cap-supplier variation.	Photographs, leak result and any change in liner or neck appearance.
Closure integrity	Whether the finished pack meets its practical sealing, tamper and consumer-opening requirement.	Transport, storage, induction sealing, product chemistry and the test procedure used.	The approved quality method, pass/fail decision and retained accepted and rejected samples.

Build a controlled test sequence

Agree the finished-pack checks before adjusting the capper.
Use production bottles, caps and liners from identifiable batches.
Confirm the cap starts correctly and the bottle is held without distortion.
Apply caps at the proposed production settings.
Label samples in run order and retain the machine setup.
Test at the agreed immediate and conditioned intervals.
Investigate outliers for thread, cap, bottle or tooling causes rather than averaging them away.

Do not publish a universal torque figure

The appropriate result belongs to the specific cap, liner, neck finish, product and quality requirement. Where a closure supplier or existing approved pack provides a target, use that as the starting evidence. Lancing should then confirm whether the chosen chuck, single-head or spindle system can reproduce the required finished-pack result without damage.

Use the bottle-cap torque-test checklist to prepare samples and the thread-engagement guide when caps sit high or cross-thread.

Link the torque test to machine selection

A bench or semi-automatic chuck capper can make it easier to isolate one bottle and cap at a time, which is useful during development and varied batch work. An automatic single-head system adds controlled bottle presentation and can be paired with cap feeding where manual placement is not sustainable. A belt or spindle capper applies tightening progressively during continuous transfer, so the bottle support, cap pre-placement and speed relationship form part of the torque result.

Define the boundary of the trial

State whether the test covers only cap tightening or also includes induction sealing, tamper evidence, leak performance, transport conditioning or consumer opening. If product residue can reach the neck finish, trial filled production samples using the agreed safe procedure. Keep rejected samples that demonstrate cross-threading, liner damage, cap marking or bottle distortion because they help identify the true operating window.

Send an approved pack and the test method used to release it.

Where no target exists, provide closure drawings, supplier information and the finished-pack risks that the capping trial must control.

Discuss torque testing Compare capping methods

Result before setting

Separate the accepted closure result from the machine setting used to achieve it.

A machine setting, application torque reading and later removal result are related but not interchangeable. Record the pack condition, timing, device/method, thread start, cap height and liner or tamper condition with each result.

Evidence	What it confirms	What it does not prove alone
Machine setting	The configured drive, clutch, head or spindle condition for the trial.	That every cap was correctly engaged or that the pack will remain accepted over time.
Immediate opening/removal check	The pack behaviour using the stated method shortly after application.	Longer-term liner, material or storage effects.
Cap height and thread engagement	Whether the closure appears seated and started on the intended thread.	Leakage, tamper performance or opening experience by itself.
Timed good-pack run	Whether the accepted result is repeatable through normal production events.	Suitability for untested component batches or formats.

When readings and pack condition disagree, use the defect troubleshooting guide before increasing or decreasing the machine setting.