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Product guide

Res-Lok concealed window restrictor

Identify the Res-Lok outward-opening casement restrictor, check compatibility, and read the supplied fitting, key-release and maintenance guidance. Match the handed version and window profile before fitting.

Model / family
Res-Lok concealed restrictor · 105 mm arm
Version
1.0

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Original UPVCSTORE product photograph showing two mirrored Res-Lok concealed restrictors and their keys; pictured quantity does not determine the selected order option.

Identify your hardware

The Res-Lok is a concealed mechanical opening restrictor fitted between the sash and frame. The supplied guide identifies the designer and manufacturer as J Banks & Co Ltd. It automatically engages and locks when the window closes, and is released with a dedicated key.

Match the handed version: JBC327 is Left Hand; JBC328 is Right Hand. Compare the manufacturer code and labelled left/right drawing with the required hardware. If unsure of the orientation, request identification help before selecting or fitting.

It is described as stainless steel with zinc alloy components in a self-colour finish. Its nominal restricted opening is approximately 100 mm; the source FAQ says the exact opening depends on the window size and fitting position.

The supplied guide’s safety section states that Res-Lok is not a child-proof barrier and cannot guarantee prevention of a fall. Keep keys away from children, move climbable furniture away from windows, supervise children, and check the restrictor’s condition and operation.

This guide applies to

The supplied UPVCSTORE product guide covers the J Banks Res-Lok concealed, key-locking restrictor for outward-opening casement windows, with a 105 mm arm and Left Hand or Right Hand versions. It does not identify a hardware revision or publication date. Match the current supplied hardware before using this guide.

Match the handed version: JBC327 is Left Hand; JBC328 is Right Hand. Compare the manufacturer code and labelled left/right drawing with the required hardware. If unsure of the orientation, request identification help before selecting or fitting.

Check compatibility

The supplied guide lists these compatible window types and materials:

  • Side-hung outward-opening casement windows.
  • Top-hung outward-opening casement windows.
  • uPVC windows with a Eurogroove.
  • Aluminium casement windows.
  • Timber casement windows.

This version is not suitable for tilt-and-turn windows, inward-opening windows or vertical sliding sash windows. The PDF directs tilt-and-turn users to a different Res-Lok version and sliding-sash users to a sash stop.

The guide describes retrofit use where the sash-to-frame gap and profile suit the device. For a top-hung window it places the restrictor on one side of the sash; match the required handed hardware using the manufacturer code and labelled drawing.

Match the handed version: JBC327 is Left Hand; JBC328 is Right Hand. Compare the manufacturer code and labelled left/right drawing with the required hardware. If unsure of the orientation, request identification help before selecting or fitting.

The PDF says each window needs one restrictor. The product selector currently offers Left Hand, Right Hand and 1 Pair; confirm the selected quantity rather than assuming every order contains a pair.

For care homes, hospitals and other settings with vulnerable occupants, the supplied guide advises contacting UPVCSTORE before ordering because a higher-strength restrictor may be needed. Where permanent guarding is required, it says this restrictor is not a substitute.

Measurements

Dimensions transcribed from the supplied PDF specification; confirm against the current hardware and window profile:

  • Arm length: 105 mm.
  • Frame part width: 16 mm.
  • Screw centres: 37 mm.
  • Restricted opening: approximately 100 mm.
  • Recommended screws: 4 mm (No.8) countersunk head, sized to suit the window profile; screws are not supplied.

The original page 3 fitting and handing drawing is retained in the fitting task. Confirm the correct hand before using it to identify a version.

The PDF reports independent testing in accordance with BS EN 14351-1:2006, Clause 4.8, for load-bearing capacity of safety devices. Its safety section reports a 350 N push-force threshold. These are attributed source statements, not independent certification of a window, installation or project.

Fitting overview

4 steps
When this task applies

The Res-Lok concealed, key-locking restrictor for outward-opening side-hung or top-hung uPVC, aluminium and timber casement windows. Confirm the hand, frame/profile suitability and current hardware match before fitting.

Match the handed version: JBC327 is Left Hand; JBC328 is Right Hand. Compare the manufacturer code and labelled left/right drawing with the required hardware. If unsure of the orientation, request identification help before selecting or fitting.

What you need

  • Drill
  • Screwdriver
  • 4 mm (No.8) countersunk-head screws sized to suit the window profile; not supplied
Before you start

Read the safety information before fitting or using this restrictor. A window restrictor is not a child-proof barrier and cannot guarantee that a fall will be prevented.

  • Keep the key out of children’s reach.
  • Move climbable furniture, including beds, sofas and chairs, away from windows.
  • Supervise children around open windows.
  • Check that the restrictor is fitted correctly and still working properly.

The supplied guide says this restrictor is not a substitute for permanent guarding where guarding is required. It directs uncertain users to Building Control, the window manufacturer or a qualified building professional.

For care homes, hospitals, supported living and other settings with vulnerable occupants, the supplied guide says a higher-strength restrictor may be required. It reports a 350 N push-force threshold for Res-Lok and refers to setting-specific HSE guidance. Contact UPVCSTORE before ordering for these settings; these source claims have not been independently certified by this conversion.

For a window used as a fire escape route, the supplied guide says to keep the key where it allows fast access in an emergency and to check applicable fire-safety requirements with the fire safety officer or Building Control if unsure.

  1. Check the kit and choose suitable fixings

    Before this step

    Match the handed version: JBC327 is Left Hand; JBC328 is Right Hand. Compare the manufacturer code and labelled left/right drawing with the required hardware. If unsure of the orientation, request identification help before selecting or fitting.

    The supplied PDF describes one restrictor in the ordered hand, one stud plate with adjustment packers if fine-tuning is needed, and one key per kit. Screws are not included.

    The current product selector offers Left Hand, Right Hand and 1 Pair, while its description refers to a pair. Check the chosen option and expected quantity with UPVCSTORE before ordering.

    The PDF recommends 4 mm (No.8) countersunk-head screws sized to suit the window profile. Ask UPVCSTORE if you are unsure which screws to use.

  2. Align the restrictor body and stud plate

    The fitting overview in the supplied PDF says that the restrictor body fixes into the window frame and the small stud plate fixes onto the sash. Both halves must line up correctly for the lock to engage.

    When the window is closed, the stud sits inside the arm of the restrictor. The arm pivots out as the window opens, and its stop catches at approximately 100 mm of opening.

    Original Res-Lok PDF drawing showing sash and frame fitting positions, stud plate dimensions and left-hand and right-hand assemblies; orientation must be confirmed before choosing a hand.

  3. Fix into suitable material

    Before this step

    The PDF provides a fitting overview, not profile-specific drilling instructions. It does not give exact hole positions, required clearances, screw length or tightening torque. If you are not confident, the guide recommends a local window fitter or handyperson.

    For uPVC windows, the supplied fitting overview says to fix into the steel reinforcement inside the profile where possible. For timber and aluminium, fix into solid material.

  4. Test the restrictor before considering fitting complete

    • Open the window and check that it stops at the restricted opening.
    • Turn the key and check that the restrictor releases.
    • Close the window and check that it re-locks.
    Expected result

    The window stops at its restricted opening, releases with the key and re-locks when closed, as described in the supplied guide.

Completion checks

Before considering the job complete, test restricted opening, key release and automatic re-locking on closing. Both halves must align correctly for the lock to engage.

Open, release and re-lock the window

3 steps
When this task applies

A correctly fitted Res-Lok concealed restrictor matching the outward-opening casement version in this guide.

What you need

  • Supplied Res-Lok key
Before you start

Read the safety information before fitting or using this restrictor. A window restrictor is not a child-proof barrier and cannot guarantee that a fall will be prevented.

  • Keep the key out of children’s reach.
  • Move climbable furniture, including beds, sofas and chairs, away from windows.
  • Supervise children around open windows.
  • Check that the restrictor is fitted correctly and still working properly.

The supplied guide says this restrictor is not a substitute for permanent guarding where guarding is required. It directs uncertain users to Building Control, the window manufacturer or a qualified building professional.

For care homes, hospitals, supported living and other settings with vulnerable occupants, the supplied guide says a higher-strength restrictor may be required. It reports a 350 N push-force threshold for Res-Lok and refers to setting-specific HSE guidance. Contact UPVCSTORE before ordering for these settings; these source claims have not been independently certified by this conversion.

For a window used as a fire escape route, the supplied guide says to keep the key where it allows fast access in an emergency and to check applicable fire-safety requirements with the fire safety officer or Building Control if unsure.

  1. Open the window to the restricted position

    As the sash swings outwards, the hidden arm extends. A stop on the arm catches against the lock body when the window reaches roughly 100 mm of opening. The window stops there until released.

    Expected result

    The window stops at the restricted opening. The source FAQ says the exact distance depends on the window size and where the restrictor is fitted.

  2. Release the restrictor with the supplied key

    Before this step

    The supplied guide also describes full opening for emergency escape. For an escape-route window, keep the key accessible quickly in an emergency and confirm the applicable fire-safety requirements. Keep the key out of children’s reach.

    Insert the supplied key into the small key barrel on the restrictor body and turn it. The arm releases so that the window can open fully for cleaning or decoration.

  3. Close the window to re-engage the restrictor

    As the sash returns to the closed position, the restrictor automatically re-engages and locks itself. The next opening is restricted again; the guide describes no separate manual re-locking step.

    Expected result

    The restrictor re-engages on closing and the next opening stops at the restricted position.

Completion checks

After closing the window, check that the restrictor has re-engaged and that the next opening is restricted again.

Routine checks and maintenance

2 steps
When this task applies

The fitted Res-Lok concealed restrictor described in the supplied guide.

Before you start

Continue to keep the key out of children’s reach, keep climbable furniture away from windows and supervise children around open windows. The restrictor does not replace these precautions.

  1. Check the fixings, engagement and key release

    The supplied guide recommends periodic checks and says “every few months” in its FAQ.

    • Check that the fixings are still tight.
    • Check that the restrictor engages when the window closes.
    • Check that the key releases the restrictor cleanly.

  2. Keep the mechanism clean and moving smoothly

    The supplied guide recommends a light wipe and a tiny amount of dry lubricant if needed. Its FAQ says to use a small amount of dry lubricant if the restrictor feels stiff.

Completion checks

The fixings remain tight, the restrictor engages on closing and the key releases it cleanly.

Troubleshooting

If you are unsure whether it fits: send UPVCSTORE photographs of the window open and closed, including the sash-to-frame gap, and ask for suitability and handing confirmation.

If you lose a key: the supplied guide says replacement Res-Lok keys are available from UPVCSTORE.

If operation feels stiff: the supplied guide recommends a light wipe and a small amount of dry lubricant if needed. Check that fixings remain tight, engagement works on closing and the key releases cleanly.

The supplied PDF does not provide a fault-repair procedure for failure to engage, failure to release or failed fixings. Ask UPVCSTORE for help with those symptoms rather than inferring a repair from this overview.

Buy this part

The replacement hardware covered by this guide. Check the identification and measurements above before ordering.

Res-Lok Concealed Window Restrictor Child Lock Res-Lok Concealed Window Restrictor – Key-Locking Child Safety Lock (LH & RH) £10.99 – £20.89 In stock3 options View product

Need a hand identifying your part?

Send clear photographs of your window open and closed, the sash-to-frame gap and the restrictor. Ask for confirmation of compatibility, Left Hand or Right Hand selection, chosen pack quantity, or replacement keys. For care settings or escape-route windows, include that information when asking for help.

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