How to s***w 2x4's together?

Question

I need to s***w the flat sides of 2 2x4s together, what type of s***w should I use, and do I need to put a nail in first?

I have little carpenting experience, by the way.

Answer 1

No need for a nail first. Just use some 3 inch "construction screws" or 3 inch nails. There is no differance between screws and nails as far as the shear value as stated by that other guy. If anything a s***w will hold better. A s***w will have the same shear value and far better tensile strength than a nail. Tensile strength being the "pull out" strength. Shear being how much force it takes to kinda snap the fastener.  Also, dont use 3 inch drywall screws. Drywall screws are black oxide which will snap like cast iron if overdriven.

Answer 2

Well you could use a drill driver and some 2" deck screws.   Or you could drill holes and bolt them together with nuts and bolts, it depends on what you are building, how much weight/stress will be on them.  You can nail them with #6 nails to hold them in place before you s***w them or bolt them together.  More info, please?  What ever you do, use plenty of screws or bolts if it going to hold much weight at all.

Answer 3

Sounds like you are trying to make 2 2x4 into 1 4x4. The thickness of the final product will be 3 inches, Use some screws 2 1/2 inches long. If you predrill clearance hole s in one 2x4, the boards will pull tight together. Just make sure the screws will apply to your application, inside drywall screws will suffice, outdoor use galvanized screws.

Good luck,

Dave

Answer 4

If you are putting the 2x4's together to support something, you are better off using nails.  Screws have very little shear strength so if there is a chance that force or pressure may cause one 2x4 to want to move independently of the other, you should use nails.

If screws are ok, the previous answer is right.  2 1/2" screws will be just right.  If you need to use nails because of shearing, use 16 penny nails, angled at about 15-20 degrees so they don't blow out the other side.  in either case, put in two fasteners every 18-20" or so.

PS, Kris J apparently hasn't learned anything about snapping off screws in his "10 years" of construction experience.  See the link below for a demonstration of s***w shear strength vs nails.