Question 1

What sizes do screws come in?

Accepted Answer

Screws come in a wide range of sizes, mainly measured by diameter, length, and thread type. Diameters can range from as small as 2mm up to about 12mm for general construction use. Lengths vary significantly, usually between 30mm and 150mm, though specialised screws may be longer.

Specific screw sizes also depend on the intended use, such as woodworking, metalwork, drylining, or structural framing. In the UK screw sizes are normally measured in mm, although metric sizes do pop up occasionally.

Buildbuddy lists a wide variety of popular screw sizes and diameters, from M3 and M4 right up to M12 diameter screw sets, as well as from 30 to 200mm in length.

Question 2

How do I measure screw size?

Accepted Answer

To measure screw size accurately, use a calliper or a precise ruler. Measure the diameter at the widest point of the threaded section. Length is measured from the underside of the screw head down to the tip. For countersunk screws, measure length from the top of the head to the tip.

Question 3

What are screws made of?

Accepted Answer

Screws are typically made from steel, stainless steel, brass, or zinc-coated metals. Steel screws are common due to their strength and durability, often zinc-plated to resist corrosion. Stainless steel screws offer greater corrosion resistance, suitable for outdoor or damp environments. Brass screws are softer, making them suitable for decorative work or delicate materials. The material you need will depend on the project requirements and conditions on-site.

Compare trade prices for screws

SPAX Yellox Countersunk Universal Woodscrews POZI 5.0 x 50mm (Box of 200)

SPAX Wirox Countersunk Chipboard Flooring Screws T20 Torx 4.5 x 60mm (Pack of 300)

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SPAX Yellox Countersunk Universal Woodscrews POZI 4.0 x 25mm (Box of 200)

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Spax Yellox Countersunk Universal Woodscrews POZI 4.0 x 30mm (Box of 200)

Spax Wirox Decking Screw T-Star Plus 4.5 x 60mm (Box of 250)

Reisser Decking Screws Bronze Coated 4.5 x 63mm (Box of 200)

Black Drywall Screws Fine Thread 3.5 x 38mm (Box of 1000)

Black Drywall Screws Fine Thread 3.5 x 32mm (Box of 1000)

Black Drywall Screws Fine Thread 4.8 x 100mm (Box of 500)

Black Drywall Screws Fine Thread 3.5 x 25mm (Box of 1000)

Timco Countersunk C2 Decking Screws 4.5 x 65mm (Box of 250)

Spax Wirox Flat Countersunk Universal Woodscrews T20 5.0 x 60mm (Box of 100)

Paslode Impulse Mini Fuel Cell Blister Pack Yellow

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Coach Screw Hex Head BZP M10 x 100mm

Coach Screw Hex Head BZP M10 x 150mm

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Spax Yellox Countersunk Universal Woodscrews POZI 4.0 x 50mm (Pack of 650)

Spax Yellox Countersunk Universal Woodscrews POZI 5.0 x 70mm (Box of 250)

Rawlplug Concrete Bolts 8mm x 90mm (Pack of 10)

Reisser Cutter Screws POZI 5.0 x 50mm (Box of 200)

Spax Yellox Countersunk Universal Woodscrews POZI 4.0 x 20mm (Box of 200)

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Spax Yellox Countersunk Universal Woodscrew POZI 4.0 x 40mm (Box of 800)

Carpenters Mate Heavy Duty Hex Head Screws 90mm (Box of 100)

Timco C2 Tongue-Fix Floor Screws 3.5 x 45mm (Box of 350)

Reisser Cutter Screws POZI 5.0 x 30mm (Box 200)

Reisser Cutter Screws POZI 5.0 x 40mm (Box 200)

Reisser Cutter Screws 5.0 x 60mm (Box of 500)

Samac Performance Plus Woodscrews 5.0 x 100mm (Box of 100)

Siniat Drywall Screws High Thread 3.5 x 38mm (Box 1000)

Rawlplug WHO Countersunk Frame Screws 7.5 x 72mm (Pack of 20)

Spax Wirox Construction Screws T30 Washer Head 6.0 x 80mm (Box of 100)

Spax Yellox Countersunk Universal Woodscrews POZI 4.0 x 45mm (Box of 200)

Optimaxx 5.0mm Woodscrew Maxxpack - Assorted lengths (Pack of 800)