No.12 (5.5mm) Pozi Countersunk Wood Screws DIN 7997 A2 Stainless

SKU: A2-7997-5.5x30
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  • Standard DIN 7997
  • Stainless grade A2 (304)
  • Drive Pozi
  • Head angle 90°
Full DIN 7997 spec sheet (PDF)All sizes and lengths, one page to print or save

How to measure DIN 7997 pozi countersunk wood screws

How to measure DIN 7997 pozi countersunk wood screws
  1. Thread: Measure across the outside of the thread with a caliper. A new screw reads its size or a touch under, so a No.8 reads 4mm or just under.
  2. Not the shank: The plain part under the head can be thinner than the thread, so don't size the screw from it.
  3. Length: Measure overall, from the top of the head to the point. On a countersunk screw the head counts.
  4. Head: The underside is a 90° cone, so it sits flush in a standard 90° countersink. The pozi recess takes a PZ1, PZ2 or PZ3 bit, as listed in the Dimensions table.

Gauge to thread size

  • No.43mm
  • No.63.5mm
  • No.84mm
  • No.105mm
  • No.125.5mm
Dimension Symbol Value
Thread diameter (nominal) d 5.5 mm
Shank diameter ds 5.02 to 5.5 mm
Head diameter dk 10.2 mm
Head height (max) k 2.75 mm
Pozi bit size PZ PZ3
Lengths available (overall, including head) L 30, 40, 50, 65, 75 mm
DIN 7997 Pozi Countersunk Wood Screws dimensions diagram
The letters match the Dimensions table above.

No.12 (5.5mm) pozi countersunk wood screws to DIN 7997, in A2 stainless steel. The head pulls flush with the surface in a countersunk hole, and the pozi recess takes a PZ3 bit.

A2 stainless resists rust outdoors, which makes these a good fit for cladding, garden projects and general joinery, inside or out. You can buy a single screw or a thousand with no minimum order, and the price breaks get better the more you buy.

What pozi countersunk screws are used for

Pozi countersunk screws are a general-purpose wood screw. The head pulls down flush, which makes them a common choice for fitting hinges, catches and other hardware. A power driver tends to slip out of a slot, but the pozi recess holds the bit well, and better than a Phillips head, so these drive cleanly with a drill driver.

Only the lower part is threaded, with a plain shank under the head. With a clearance hole in the top piece, the thread grips just the bottom piece and clamps the joint together.

Under the head is a 90° cone, which sits flush in a hole cut with a standard 90° countersink bit. US imperial flat head screws use an 82° head, so they won't sit exactly right in a 90° countersink.

Choosing a size

A bigger gauge number means a thicker screw. At 5.5mm across the thread, the No.12 is the largest in this range, above the No.10 (5mm).

A countersunk screw is measured overall, from the top of the head to the point, since the whole screw finishes in the wood. You can choose from 5 No.12 lengths between 30mm and 75mm.

Expect a new No.12 to measure 5.5mm across the thread, or a fraction under, because 5.5mm is the nominal size. The shank below the head can be narrower, down to 5.02mm, and that's within the standard. You'll find both figures in the dimensions table.

Material: A2 stainless

These are A2 stainless, the everyday grade for fixings and part of the same family as 304 and 18/8. It handles rain and damp, which is why it's so widely used on outdoor timber. A2 is close to non-magnetic, so don't worry if a magnet pulls slightly.

For coastal or poolside jobs, A4 holds up better against salt. See our guides to A2 stainless steel and A4 stainless steel for the difference.

Pozi screw questions

What size is a No.12 screw in mm?

The thread on a No.12 is 5.5mm across. These are made to DIN 7997, which also sets the head: 10.2mm across and 2.75mm high at most, with a PZ3 pozi recess.

Gauge sizes come from imperial screws. Ours are metric, and a 5.5mm thread is the nearest match to an imperial No.12, which is about 5.5mm.

What bit do No.12 pozi screws need?

A PZ3 pozi bit. Pozi and Phillips heads look alike, but a pozi head has four small tick marks between the arms of the cross, and the bit has ribs to match.

A Phillips bit will turn a pozi screw, but it doesn't seat fully and tends to slip out as the screw tightens, which can damage the head. With the right bit, a pozi head takes more turning force before the bit slips.

If you'd rather use a flat-blade screwdriver, our No.12 slotted countersunk wood screws have the same head with a slot.

What is a No.12 x 2 inch screw in mm?

Go for 5.5 x 50mm, the nearest metric size. Every length is listed in inches and millimetres, for example 1 1/4in (30mm), 2in (50mm) and 3in (75mm), because plenty of people still think in inches. The screws are made to metric lengths, so a 2in screw here is 50mm rather than 50.8mm.

How do I measure a No.12 pozi screw?

Hold a caliper across the outside of the thread. A new No.12 reads 5.5mm or a touch under, because 5.5mm is the nominal size. DIN 7997 lets the plain shank below the head go down to 5.02mm, so treat that as a separate reading.

Length is measured overall, from the tip to the flat top of the head.

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Some of the reviews shown are from related products the merchant grouped with this one.
A
Anonymous (United Kingdom)
No 6 ( 3.5mm ) / 1 1/4" ( 30mm )

Excellent quality and Boltbase were about the only people who had them

We're glad to hear you were able to track down these hard to find screws on the Bolt Base website. Thanks for your review, appreciate it.

Iain

A
Anonymous (United Kingdom)
No 10 ( 5mm ) / 1" ( 25mm )

Its the best place to get your stainless
Wood screws and bolts 🔩

Here Here John, Couldn't have said it better myself!😀

Cheers for your review for Bolt Base.
Iain

N
Neil Dunlop (United Kingdom)
No 12 ( 5.5mm ) / 1 1/4" ( 30mm )

They are fine, though a mm short of the listed length.

Morning Neil,

Thanks for taking time to review your wood screws from Bolt Base.

These din 7997's are listed showing the imperial size and the closest equivalent metric size. The result of this is that there may be a slight mm of a difference to what is listed. Sorry if this was not clear for you.

Cheers
Iain