Screw anchor

A screw anchor is a fastener that can attach one object to another in situations where screws, nails, adhesives, or other simple fasteners are either impractical or ineffective. Different types have different levels of strength and can be used on different types of surfaces.

Expansion anchors

These are often called "lead anchors" or "plastic anchors", and are used as follows:

1. Drill a hole the same size as the anchor body.
2. Push the anchor to its full depth in the hole.
3. Insert the screw through the item being fastened and screw it into the anchor tight.

Other types

Other types of anchors, designed especially for fastening to hollow walls, include "toggle bolts" and "molly bolts".

How to use

For plastic screw anchors use drill bits as shown below:

Anchor Size	Screw Size	! Use Drill Size
	W	in.	gauge	mm
3/16 x 3/4	#4 - #8	3/16	11	4.8
3/16	#6 - #10	3/16	11	4.8
1/4	#10 - #12	1/4	E	6.2
5/16	#14 - #16	5/16	N	8.0

See also

• Wall plug
• Wedge anchor