In order to do this installation correctly so it has maximum strength and security it will require some significant preparation.

Research Links

Used Door on Craigslist

Phone= (216) 524-7600 is the number listed on the ad
Steel Doors – 70 (Valley View) – in the Cleveland Craigslist
They have multiple units of this door. All are no window versions.
Steel Pre Hung 36" x 80" Push Bar – 3 hour Fire Rated – 250
Steel commercial man doors fire proof – 150 (Newburgh Heights)
Doors for less – Cleveland
Steel Door – Cleveland
Doors for less – 100 (Westside)

Related Work

The following gallery is helpful in identifying common features of steel doors

Alright now I have 4 commercial doors with knock down frames that I found in Capon Bridge, WV that were being removed from a church. The frames are 40 inches wide and thus I need to cut 5/8 inch out of both sides of the masonry hole I want to put the door in. Best tool so far that I have found is a hand held circular saw with a diamond blade. It is a standard 7.25 inch saw and blade and it is cutting well but the cut depth is only 2 inches. That's leaving the rest of the 5.5 inch depth uncut. That is the next problem to be solved. There are 16-5/16" circular saws but they generally cost north of 500 USD. Thus I either need to borrow a saw, rent a saw or hire the cut job to be done. I tried using a reciprocating saw with diamond blade but it is very very slow.

I decided to use a Harbor Freight cheapy with laser guide line: 7-1/4 in. 12 Amp Heavy Duty Circular Saw With Laser Guide System – Chicago Electric Power Tools – Item#63290 to make a first set of cuts because it is easier to get a straight line with the laser guideline projected on the surface line I ruled onto the wall.

Note: This unit developed a rough bearing during the course of cutting the guide cuts. This may have been due to the extremely dusty nature of cutting cinder block. Not sure if I can do anything to remedy that.

Research Links

Klutch 14in. x 0.118 x 1in. Segmented Diamond Blade
Google: Stihl TS800 – 16 inch gas cutoff saw
Ebay: Stihl: TS800
TandM hardware rental page for Stihl TS800 – using my 7.25 circular saw I can set up guides by doing 2 inch deep cuts then follow that with this tool.

TS 800 STIHL Cutquik® Specifications – Professional Use
DISPLACEMENT	98.5 cc (6.0 cu. in.)
ARBOR SIZE	20 mm
MAXIMUM WHEEL SIZE	400 mm (16")
MAXIMUM CUTTING DEPTH	143 mm (5.6")

TS 420 STIHL Cutquik® Specifications – Professional Use
DISPLACEMENT	66.7 cc (4.07 cu. in.)
ARBOR SIZE	20 mm
MAXIMUM WHEEL SIZE	350 mm (14")
MAXIMUM CUTTING DEPTH	125 mm (4.9")

I went to Harbor Freight to buy a cutoff wheel for the corners etc and while I was there I noticed they had a 14 inch cut off saw. Upon inspection I saw that this saw had an easily reversible hinge joint. See image below:

14 in. 2 HP Cut-Off Saw Drill Master – Item#91938

Click for larger view

When I got this saw home I removed the Jesus clip and spun the chop arm 180 degrees so now it was very well set up to cut a wall slot. You can see the wall cutting orientation in the two "Roman siege towers" made out of cement block. This methodology allowed a T square to be used to maintain the 14 inch diamond saw blade square to the wall. Above the left photo you can see how I mounted a used blower unit above the work area. This rapidly exhausted the dusty air out of the building. This is highly recommended.

Before photos. A very old door with very insecure windows. The hole plugged after the masonry cuts were finished waiting for the next day's dry fitting and mounting of door frame and door.

Resulting cut photos are next. The remaining material was abraded away using a hammer drill to perforate where the blade's cut depth was insufficient and then a chisel and hammer was used to tap and break away the material. The first photo below shows an area that was perforated before smoothing. The area was smoothed using a 4 inch diamond blade in a small cut off / grinder tool.