UK TOOLS, DIY & HOMECheck the model. Check the fit.
Fixings & Hardware / BUYING REFERENCE

Wood-screw sizes and packs

Record the screw diameter, length, head and drive type before comparing packs. A box described as wood screws can contain different thread forms and finishes intended for different applications. Measure the components being joined, then use the screw manufacturer’s guidance to select the appropriate specification. For replacement work, keep the original fitting’s instructions available rather than simply copying a worn screw. An assortment is useful when its sizes suit your jobs, not just because the total number of pieces is large.

Ad · affiliate linkSearch Amazon UK

Search results. Match the specifications below to the selected listing.

Read a wood screw’s diameter, total length, thread length, head, drive and finish as separate fields. Two packets labelled 4 mm can differ in almost every other buying detail. The exact Fischer UK articles below show how to compare those specifications without guessing from a photo or pack headline.

Wood-screw diameter and length are different measurements

Fischer’s UK tables separately label diameter d, length l and thread length lg. Article 670217 is 4 mm in diameter and 40 mm long, with 28 mm of thread. Article 657182 is also 4 mm in diameter, but 70 mm long with 42 mm of thread. Diameter alone cannot select the same screw.

Carry the complete size and article code into the retailer listing. If the proposed fixing involves a wall plug, use the plug maker’s documented screw requirements and account for the actual fixture; the wood-screw diameter is not automatically the required masonry drill diameter.

Two exact countersunk PZ2 examples

Both named examples have a countersunk head, PZ2 drive and partial thread. Their material, lengths and pack quantities differ. The table records published UK variants; it does not select a screw length or approve a joint for your project.

Two exact countersunk PZ2 examples
Fischer articleDiameter × length / threadMaterial or finishDrive / stated packSource
670217 · PowerFast II CZP4 × 40 mm / 28 mmBlue-passivated zinc platingPZ2 / 200 piecesManufacturer reference ↗
657182 · PowerFast SZ A2P4 × 70 mm / 42 mmA2 stainless steelPZ2 / 100 piecesManufacturer reference ↗

Check the head, drive and application before buying

Fischer describes these countersunk heads for flush installation in wood and the partial thread for drawing timber elements together. Those are characteristics of the named products, not a universal rule for every screw, material or joint. The 657182 reference lists hardwood as pre-drilled; consult the instructions for the actual screw and workpiece.

Match the driver marking rather than choosing a similar-looking cross-head bit. Compare the stated material and finish with the manufacturer’s intended environment. For a structural connection, use a specified fixing and installation design; neither a diameter table nor a generic Amazon search establishes load capacity.

Make the pack comparison useful

Record quantity as well as dimensions and finish. Check the selected variant, screw count and whether the listing identifies the same article. A mixed assortment can be useful only if it contains the sizes and head types you actually need. Search by the confirmed specification and keep the manufacturer reference available while comparing offers.

Comparison sources

Manufacturer references checked 2026-10-03. These examples describe published specifications, rather than a hands-on review.

MATCH THE DETAILS TO YOUR JOB

What to check before buying

  1. Separate thread diameter, total length and thread length.
  2. Match the exact head and drive, including the PZ2 marking in these examples.
  3. Confirm material, finish, intended application and any pre-drilling instructions.
  4. Check wall-plug screw requirements separately when applicable.
  5. Match the specified fixing and installation for structural work.
  6. Confirm article, selected variant and pack quantity on Amazon.

Reference & scope

Amazon UK product-type search

This page is a selection checklist for a product type. The manufacturer instructions and exact retailer listing determine suitability, included accessories and available variants.

More in this department

Browse department ↗