Rakesh,
I'm sorry but I don't completely understand your question.
If you are looking for how to install hollow metal frames, SDI 122 goes into great detail here: http://www.commdoor.com/Installation%20Instructions.pdf. I also go into detail on this web site here: http://www.commdoor.com/hmf.html along with some helpful diagrams. I talk about knockdown frames (not welded but in 3 loose pieces) as well as welded hollow metal frames installation. You didn't specify which type you are referring to but I do cover both. You can also go here: http://www.commdoor.com/anchors.html to see more anchoring details.
You did not specify the type of wall you have or knockdown versus welded frame so I have included information for all types below for the rough opening size you'll need. Please also note the statements below about the drywall extending into the hollow metal frame at least 1/2" on fire rated openings.
Rough opening size, kd dw frame: Take the nominal door width and add 1 1/2" and the nominal door height and add 3/4". Keep in mind that on a 3068 door, the nominal measurments are 3'0" x 6'8" while the actual measurements are 2' 11 3/4" x 6' 7 1/8". Using a 3068 door as an example, the rough opening size for a kd frame would be 3' 1 1/2" x 6' 8 3/4". This will allow the frame to partially wrap the wall at all 3 sides. You can increase the rough opening size a bit if needed but remember that the drywall must extend at least 1/2" into the frame at fire rated openings.
Rough opening size, welded frame: Take the nominal door width and add 4 1/4" and the nominal door height and add 2 1/4". Keep in mind that on a 3070 door, the nominal measurements are 3'0" x 7'0" while the actual measurements are 2' 11 3/4" x 6' 11 1/8". Using a 3070 door as an example, the rough opening size for a welded frame would be 3' 4 1/4" x 7' 2 1/4". Since the standard face on a hollow metal frame is 2", the outside dimensions of a 3070 frame will be 3'4" x 7'2" so this RO dimension will give you 1/4" of "play". If you are installing a welded frame into a fire rated stud wall, remember that the drywall will have to extend at least 1/2" into the frame so you can not simply butt the drywall up to the frame at fire rated openings. On non-rated openings you can run the drywall down to the frame or caulk the seam if it is going into block.
I hope this has answered your question. If not, please let me know.
Steve Behrens
steve@commdoor.com
http://www.commdoor.com
