How to choose the correct screwdriver bit for the tool?

3rd March 2020

	How to choose the correct screwdriver bit for the tool


	Shop for Screwdriver bits


			Screwdriver bits are used in power tools such as cordless screwdrivers, corded / cordless drill and impact drivers. To use a screwdriver bit in your tool’s chuck, you must ensure that it is the right size.

			Step 1 – Find out the tool’s chuck size
			The chuck is the part of the tool that holds the detachable accessories such as screwdriver or drill bits.

			Most cordless screwdrivers and impact drivers have 6.35mm (¼ inch) chucks. Cordless drill drivers have either 10mm (3/8 inch) or 13mm (½ inch) chucks. A tool’s chuck size tells you the maximum shank diameter it will accept. So a tool with a 10mm chuck will accept screwdriver or drill bits with 10mm shanks.

			If you are unsure of your chuck size, there are several ways you can find out: 1. Information such as the chuck size can usually be found on the tool’s original packaging, or in the instruction manual. If you don’t have these items, then consult the manufacturer.

			2. You can also get a rough idea of the tool’s chuck size by measuring across the diameter of the chuck with a tape measure or ruler. The diameter will tell you the maximum shank diameter it can accept.

			3. Another way to find out the chuck size is to take your cordless impact driver into a tool shop. The staff will either be able to tell you the chuck size from looking at the chuck, or will try different bits to see which one fits.

			Step 2 – Find out the bit’s shank diameter
			The shank is the part of the bit that is actually gripped by the tool.

			All screwdriver bits have a hexagonally shaped shank with a flat bottom. The shank diameter is measured across the flats. The shank size will often be stamped across the side of the bit on some models. Most screwdriver bits have a shank diameter of ¼ inch (6.35mm). This means they can be used in tools with a ¼ inch chuck size.

			Now you know your chuck size you can pick a screwdriver bit with the correct size shank diameter.

			Please note: For quick-release chucks or chucks with magnetic bit holders, the shank diameter must be the same as the chuck size, in order to fit.

			For chucks with three jaws, the shank diameter can be the same size or smaller than the chuck size, as the chuck’s jaws can be adjusted to accept bits with smaller shanks.