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

Coach Screw Hex Head BZP M10 x 50mm

Spax Yellox Countersunk Universal Woodscrews POZI 5.0 x 40mm (Box of 200)

Coach Screw Hex Head BZP M12 x 100mm

Coach Screw Hex Head BZP M8 x 50mm

Siniat Wet Area Screws Coarse Thread PH 42mm (Box of 1000)

Coach Screw Hex Head BZP M8 x 100mm

Siniat Drywall Screws High Thread 4.2 x 65mm (Box of 500)

Siniat Self Drilling Drywall Screws Wafer Head 4.2 x 12mm (Box of 1000)

Siniat Self Drilling Drywall Screws Wafer Head 4.2 x 13mm (Box of 1000)

OJ Vortex Power Screws 6.0 x 200mm (Pack of 15)

Spax Wirox Frame Anchor Screw T30 7.5 x 80mm

Spax Yellow Countersunk Universal Woodscrews POZI 5.0 x 100mm (Box of 135)

Spax Wirox Flat Countersunk Universal Woodscrews T-Star 6.0 x 140mm (Pack of 100)

GTEC Self Tapping Drywall Screw 65mm (box Of 500)

GTEC Self Tapping Drywall Screw 50mm (box Of 1000)

OJ Green Timberdrive Screws Hex 7.0 x 100mm (Pack of 25)

British Gypsum Black Drywall Screws 50mm (Box Of 500)

Rawlplug Self Drilling Screw With Washer 4.8 x 16mm (Pack of 100)

Black Drywall Screws Fine Thread 3.5 x 32mm (Box of 200)

Coach Screw Hex Head BZP M10 x 130mm

Reisser Cutter Screws POZI 5.0 x 100mm (Box of 200)

Reisser Cutter Screws POZI 5.0 x 120mm (Box of 200)

Reisser Cutter Screws POZI 5.0 x 90mm (Box of 200)

Reisser Cutter Screws POZI 5.0 x 80mm (Box of 200)

Carpenters Mate Heavy Duty Hex Head Screws 6.3 x 90mm (Pack of 250)

Coach Screw Hex Head BZP M10 x 70mm

Coach Screw Hex Head BZP M6 x 40mm

TIMCO Coach Screws 10 x 150mm (Pack of 18)

Carpenters Mate Exterior Wood Screws 4.9 x 63mm (Box of 500)

Carpenters Mate Exterior Wood Screws 4.9 x 75mm (Box of 400)

Spax Yellox Countersunk Universal Woodscrews POZI 5.0 x 60mm (Box of 350)

Rawlplug Countersunk Concrete Screw 7.5 x 132mm

Screw Cover White (Pack of 50)

TIMCO Green In-Dex Timber Screws Hex Head 6.7 x 150mm (Pack of 50)

TIMCO Concrete Screws ZYP 7.5 x 100mm (Box of 100)

Spax Countersunk Stainless Steel Screws T-Star 4 x 40mm (Pack of 25)

Spax Countersunk Stainless Steel Screws T-Star 3.5 x 30mm (Pack of 25)

Spax Countersunk Stainless Steel Screws T-Star 5 x 50mm (Pack of 25)

Reisser Cutter Screw POZI 5.0 x 100mm (Box of 250)

Reisser Cutter Screw POZI 5.0 x 80mm (Box of 400)