No.8 (4mm) Slotted Raised Head Countersunk Wood Screws DIN 95 A2 Stainless

No.8 (4mm) slotted raised head countersunk wood screws to DIN 95, in A2 stainless steel. The underside sits in a countersunk hole, and a shallow dome on top stands just proud of the surface. The single slot takes a flat-blade screwdriver.

In A2 stainless they're happy outdoors, on cladding and garden work, as well as on joinery and fixings indoors. Order one screw or a thousand, there's no minimum, and generous price breaks bring the cost down the more you buy.

Where raised head screws are used

Raised head screws are made to be seen. Where a screw head stays on show, the rounded dome gives a neater finish than a flat head. They're often used to fix hinges and other fittings to wood, and a slotted head looks right on older doors, furniture and joinery.

For a cross-head version, our No.8 pozi raised head countersunk wood screws have the same domed head with a PZ2 recess.

The thread runs only part way up, leaving a plain shank under the head. Drill a clearance hole through the top piece and the shank slides through it, so the thread pulls the two timbers tight.

The underside of the head is a 90° cone, so a standard 90° countersink bit gives the right seat. Only the dome stands above the surface.

Picking the right size

Gauge numbers go up as screws get thicker. The No.8 measures 4mm across the thread, which puts it between the No.6 (3.5mm) and the No.10 (5mm).

Length on a raised head screw is measured from the point to the top of the countersunk part, where the head meets the surface. The dome isn't counted, because it stays above the wood. Lengths for the No.8 run from 16mm to 50mm, 8 in all.

4mm is the nominal size, so a new No.8 reads 4mm across the thread or slightly less. The plain shank under the head may be slimmer, as little as 3.52mm, which is normal, and the dimensions table gives both.

A2 stainless steel

A2, also sold as 304 or 18/8 stainless, is the standard grade for everyday fixings. Rain and damp don't trouble it, so it's the usual pick for outdoor timber. It's almost non-magnetic, though a light pull on a magnet is normal.

Salt air and pool water are harder on stainless, and A4 lasts longer there. Our A2 stainless steel and A4 stainless steel guides compare the two.

Raised head screw questions

What size is a No.8 screw in mm?

No.8 wood screws have a 4mm thread. These are made to DIN 95, which also sets the head: 7.5mm across, 2.2mm at most from the underside to the rim, a dome of about 1mm on top, and a 1.0mm slot.

No.8 is a trade size from the imperial system. These are metric, with a 4mm thread, the closest metric size to an imperial No.8 at about 4.2mm.

What's the difference between raised head and countersunk screws?

Both have the same countersunk underside and fit the same 90° countersink. A flat countersunk screw (DIN 97) finishes flush with the surface, while these raised head screws have a shallow dome that sits slightly proud. The slot is cut deeper too, because it runs through the dome.

If you need a flush finish, see our No.8 slotted countersunk wood screws.

What is a No.8 x 1 inch screw in mm?

It's 4 x 25mm, the closest metric size. People still ask for wood screws in inches, so every length on this page shows both, for example 3/4in (20mm), 1in (25mm) and 2in (50mm). We make them to the metric length and quote the nearest inch size, so a 1in screw here is 25mm rather than 25.4mm.

How do I measure a No.8 raised head screw?

Use a caliper across the outside of the thread. A new No.8 reads 4mm or slightly less, as 4mm is the nominal size. The plain shank under the head can be thinner, and DIN 95 allows it down to 3.52mm, so measure it separately.

For length, measure from the point to the top of the countersunk part, where the head meets the surface. Leave the dome out.