Expert: Dan Griffin - 8/14/2008

Question
dear Sir. I'm trying to put up shelving on a wall that has metal studs under 1/2" sheet rock, wood and metal screws do not hold! I got some ( E-Z ancors ) made of plastic and also some made of aluminum that are called Auger Anchors, I also picked up some molly hollow wall anchors
6-32X2-3/8" and I do not know which to use, I don't want to make a mess of the wall, can you please help. Thank you H.DeEsposito

Answer
The best answer would be to have wood backers installed in the studs before drywall where substantial loads will be installed.  Apparently you are past that point.  Is there any way to get into the wall above ceiling to get some wood backers behing the drywall?  You've not given much information about the shelving, but I have a mental picutre of metal shelf standards that don't coincide with the studs.  I have had good luck with   ZipIts from Powers:
http://www.powers.com/plastics_hollowwall.html
The best strengths are the strap toggles and the toggle bolts.  You can go to their individual pdf links to see pull outs and shear loads in 1/2" drywall as well as installation details.  These anchors are all subject to the strength of the drywall unless you position them in the studs.

If you are hanging a cabinet of some description, look into using a French cleat type installation:
http://www.youtube.com/watch?v=zP6mP_bApGY