Gyproc Metal-to-Metal Screw, 4.2 X 13mm, 500 Nos Pack

• Manufacturer: Gyproc (Saint-Gobain)
• Product: Metal-to-metal screw — joins grid components to each other
• Size: 4.2 x 13 mm · Pack: Box of 500
• Self drilling: The point bores its own hole through the steel — no pilot needed
• Wafer head: Wide and low profile, so it sits almost flush under the board
• Zinc plated steel with a cross-head drive
• For steel framing only — not for fixing plasterboard
• Used with ceiling angles, intermediate channels, perimeter channels and studs

Gyproc Metal-to-Metal Screw 4.2 x 13 mm is the self-drilling fixing that joins the steel components of a drywall or ceiling grid to each other, in a box of 500.

It is worth being clear about which of the two Gyproc screws this is, because they come in similar boxes and do opposite jobs. A drywall screw fixes the board to the grid. This metal-to-metal screw assembles the grid itself — ceiling angle to cleat, channel to channel, stud to track, perimeter to framing. A complete ceiling or partition needs both, and ordering only one is the commonest way a job stalls halfway through.

Self drilling means the point bores its own hole straight through the steel as you drive it. There is no pilot hole and no marking out — you position the sections, drive the screw, and it cuts and clamps in a single action. That matters when you are assembling a grid overhead and every extra step is repeated hundreds of times.

The wafer head — wide and very low profile — is the detail worth understanding, because it is chosen for a specific reason. These screws join sections that plasterboard is then fixed over. Any raised head sitting between the steel and the board creates a bump, and that bump telegraphs through the finished ceiling as a visible high spot under raking light, long after the skimming and painting are done. A wafer head sits almost flush, so the board beds down flat. It also spreads its clamping load across a wide area of thin steel, which is what a sheet-to-sheet joint needs.

Technical Specifications

Applications

1) What is the difference between this and a drywall screw?

They do opposite halves of the job. This metal-to-metal screw assembles the steel grid — section to section, stud to track. A drywall screw fixes the plasterboard onto that grid. A complete ceiling or partition needs both types, and ordering only one is the commonest way a drywall job stalls halfway.

2) What does “self drilling” mean?

The point bores its own hole through the steel as you drive it — no pilot hole and no marking out. That is different from a self-tapping screw, which cuts a thread but needs thinner material or a pre-drilled hole. Position the sections, drive the screw, and it cuts and clamps in one action.

3) Why is the head flat and wide?

Because plasterboard gets fixed over these screws. A raised head sitting between the steel and the board creates a bump that telegraphs through the finished ceiling as a visible high spot under raking light — discovered after skimming and painting. A wafer head sits almost flush so the board beds down flat, and it spreads clamping load across thin steel.

4) Can I use these to fix plasterboard?

No. The wafer head will not countersink into board — it sits proud of the surface and tears the paper face, leaving the fixing holding almost nothing. Plasterboard needs a drywall screw with a head shaped to seat just below the paper without breaking it.

5) How many will I need?

That depends on your grid layout and the fixing spacing your system specifies — every crossing, splice and junction takes screws. Work it from the design rather than a rule of thumb, and note that grid assembly generally uses fewer screws than boarding does, so a box of metal-to-metal screws goes further than a box of drywall screws on the same job.

1. Return within 24 hours of delivery for:
   • Damaged or defective product
   • Wrong or missing item
2. Product cannot be returned once installed or used
3. Refer to Refund Policy for complete details

Please check on delivery that this is the metal-to-metal box and not the drywall screw — the two are easily mixed up and are not interchangeable.