How to Cut Tempered Glass to Size

The honest answer is that you cannot cut tempered glass to size. Once glass has been toughened, any attempt to cut, drill, or grind it will make it shatter. If you need a specific size or holes for hardware, all machining must be done before tempering.

Best in Glass is a supply-only partner for the trade. We are based in Staffordshire and deliver nationwide. We manufacture made-to-measure panels and stock common sizes. If you want help specifying sizes, holes, or edges, call 01889 226444 or email contact@bestinglass.uk.

Why you cannot cut tempered glass

Tempering is a heat treatment. The sheet is heated and then cooled very quickly. This locks the surface in compression and the core in tension. That stress profile gives strength and a safe break pattern. It also means that any new cut or drilled hole upsets the balance and the sheet fails.

If a panel arrives a few millimetres too big, you cannot shave it down. If a hinge hole was missed, you cannot add it on site. The safe fix is to reorder the correct specification.

What to do instead

Plan every change while the glass is still annealed. The correct workflow is:

• Cut to final dimensions

• Add holes, notches, and any shaping

• Finish the edges to the required quality

• Toughen the finished piece

This sequence delivers the size you need with the safety you expect. It applies to partitions, balustrades, doors, and furniture tops.

What you can specify before tempering

• Exact sizes to the millimetre

• Edge finishes such as arrised or flat-polished

• Holes for hinges, handles, and brackets

• Notches for channels and hardware plates

• Radius corners and shaped profiles

• Thickness to suit the system, often 10 mm or 12 mm for interiors

If you need fixings, seals, or trims that work with glass, see our range of glass hardware and tools.

Measuring and tolerances that prevent reorders

Getting the sizes right first time saves time and money.

• Measure the opening in several places and work to the tightest point

• Allow sensible fitting clearance for channels, gaskets, and movement

• Follow hardware drawings for hole diameters and edge distances

• Keep hole sizes and corner radii consistent across a batch

• Provide a clear sketch or CAD with all dimensions labelled

If you are unsure about clearances for your system, email a quick drawing to contact@bestinglass.uk and we will sense-check it.

Typical trade uses where accuracy matters

• Glass partitioning. Panels must fit U-channels and door hardware with tight tolerances. Browse our glass partitioning systems for components and ideas.

• Balustrades and railings. Clamp centres and base shoes set exact sizes. Explore glass balustrades and railings.

• Furniture and interiors. Polished edges and radius corners give a clean, safe finish. See our glass table tops.

For simple protectors and shelves where tolerances are forgiving, check the current catalogue of stock products.

Alternatives when you need flexibility

You might not know the final size until other trades complete their work. In that case:

• Order annealed first for a site check, then confirm the final spec to be toughened

• Choose systems that allow small adjustments with gaskets or packers

• Use trims where appropriate to cover minor variation

These options do not replace accurate measuring, but they can make installs smoother.

Safety notes and handling

Tempered glass improves safety and durability in service. It still needs careful handling.

• Do not attempt to grind, sand, or drill a tempered pane

• Protect edges from impacts during transport and install

• Keep edges dry and clean, especially near wet areas such as bathrooms

• Use suitable sealants and adhesives intended for glass

If you need guidance on the right thickness or edge type for your system, speak to our team.

Ordering checklist

Include the following in your enquiry for a fast, accurate quote:

• Panel sizes in millimetres and required thickness

• Edge finish: arrised or flat-polished

• Holes and notches with sizes and centres from the nearest edges

• Corner details, such as radius size

• Quantity, delivery postcode, and your timeframe

• A simple drawing, PDF or DWG

Send your details to contact@bestinglass.uk. We will confirm lead times and delivery options for your route.

Why trades choose Best in Glass

We supply the UK from our Staffordshire base with both bespoke and stock options. Reviews often mention helpful advice and reliable service. Our aim is to help you order once and install with confidence. If you want straight answers on tolerances and hardware, call 01889 226444.

FAQs

Can I cut tempered glass to size on site?

No. Any attempt to cut or grind a tempered sheet will cause it to shatter. All machining must be done before tempering.

Can I drill a hole in tempered glass after delivery?

No. Add every hole and notch during manufacture while the sheet is still annealed.

What thickness should I choose for partitions and doors?

Many interior systems use 10 mm or 12 mm, but always follow the hardware supplier’s guidance for thickness, hole sizes, and edge distances.

What if my panel is a few millimetres too big?

Do not try to trim it. Reorder at the correct size or speak to your system provider about gaskets and allowances.

Do you deliver made-to-measure tempered glass nationwide?

Yes. Lead times vary with size, processing, quantity, and location. Share your spec and deadline and we will advise.