How to Measure uPVC Window Handles: Spindle and Screw Centres

Replacing or upgrading upvc window handles is straightforward when measurements are taken correctly. Accurate measurements of the spindle and screw centres ensure a new handle fits correctly and operates smoothly, avoiding wasted time and returns. This guide explains the practical steps tradespeople and homeowners should follow, covers common sizes and pitfalls, and highlights what to check before ordering replacement upvc window handles.

Identify the handle type first

Different handle types require different measurements:

• Espagnolette (espag) handles operate a long locking rod and usually have a square spindle and two mounting screws through the backplate; an example product is the TSS Cockspur Window Handles.
• Cockspur handles sit on the bead of the opening and have a simple bolt that hooks over the frame; an example product is the TSS Cockspur Window Handle.
• Standard non-locking or locking lever handles can vary in fixing method and spindle size; the TSS Offset UPVC Window Handles is a common style.

Recognising the type avoids unnecessary measurements and helps choose matching fixings.

Tools required

• Metric ruler or tape measure (preferably digital calliper for accuracy)
• Flat screwdriver to remove handle
• Pen and paper or phone to photograph and note measurements

Measuring the spindle

1. Remove the handle: Use a screwdriver to undo the fixing screws. Keep screws safe as they may differ from replacements. 2. Identify the spindle cross-section: Most upvc window handles use square spindles (commonly 7 mm square), though 6 mm spindles are also found. Measure the width across flats with a calliper or ruler to the nearest 0.5 mm and note whether it is square or another profile. 3. Measure spindle length: Measure from the inside face of the handle backplate to the end of the spindle that engages the mechanism. If the spindle is mounted flush with the backplate edge, measure from that edge. Record total protruding length and note whether the spindle is centred or offset relative to the backplate. Replaceable spindles are sometimes adjustable; if unsure, measure the distance required to clear any escutcheon or backing plate.

Practical tip: If the spindle is still in the gearing (i.e., the handle removed but spindle remains in the gearbox), measure from the face of the window frame to the spindle end.

Measuring screw centres

Screw centres are the distance between the centre points of the mounting screw holes on the backplate. This is critical to ensure the new handle lines up with existing holes.

Steps: 1. With the handle removed, measure the distance from the centre of one fixing hole to the centre of the other fixing hole in a straight line (horizontal or vertical as appropriate). Use a ruler or tape measure and record in millimetres. 2. Measure any additional mounting points if present (some handles have three fixings or an additional security screw). 3. Note the thread size and screw head type currently used so new fixings can match or replacements provided.

Common sizes: Many upvc window handles use 43 mm screw centres, but variations exist. Measuring directly avoids relying on assumptions.

Other important measurements and checks

• Handing and orientation: Note whether the handle is left- or right-handed when the window faces outwards. Also check whether the handle is for top hung, side hung, or bottom hung windows as locking rods and fixings change.
• Backplate size and shape: Measure the height and width of the backplate if the new handle must cover old screw holes or match the aesthetic.
• Locking mechanism: For keyed or thumbturn locking handles, note the position of the cylinder or thumbturn relative to the spindle and mounting holes.
• Bead clearance for cockspur handles: Confirm the handle’s strike clears the bead and glass when closed; cockspur handles often require a specific projection.
• Condition of existing fixings and gearbox: Worn gearboxes, stripped threads or rusted fixings can require repair or different screws.

Ordering guidance and compatibility

• Match spindle profile first, then length. A correct square spindle (e.g., 7 mm) is essential for torque transfer.
• Match screw centres to avoid drilling new holes. If choosing a different backplate size, ensure it will cover previous holes neatly.
• For security-critical windows, opt for locking espag handles designed to meet local standards and retrofit compatibility. The Mila ProSecure Espag Handle offers enhanced security features and is designed to replace common espag variants.
• Cockspur replacements should match the hook projection and screw centres; the TSS Cockspur Window Handle is a typical replacement for many surface-mounted applications.
• For general-purpose lever handles, the Yale Sparta Window Handle is a popular choice and fits many standard upvc fittings.

Common mistakes to avoid

• Measuring total handle length instead of spindle length results in wrong purchase.
• Assuming spindle size; visually similar spindles can be different (6 mm vs 7 mm).
• Forgetting to note handing or the position of locking cylinders.
• Using imperial tools or fractions; always record in millimetres for UK suppliers.

Final checks before fitting

• Compare the new handle’s spindle width, length and screw centres exactly with recorded measurements.
• Check that supplied screws are correct length to avoid penetrating the frame or being too short.
• Test operation before securing fully: fit handle loosely, operate the window several times, then tighten fixings.

Precision in measuring the spindle and screw centres removes guesswork and speeds up replacement or upgrade jobs. Tradespeople will value the time saved by recording spindle profile, exact protruding length and fixing centre dimensions; homeowners benefit from a smoother, correct installation on first attempt.

Window Handles Guide