I wanted an attractive sturdy metal case for my iPhone 4S that protects the phone from damage, especially its screen; and allows easy removal of the phone from the case. The phone should also not easily fall out of the case. This case could be made to fit many smart phone models, but I would want a cover for the phone so nothing scratches the phone's screen through direct contact.

The photo shows my finished case. It has a belt loop and the phone rests horizontally at my side. Yes, my phone would be more easily accessible if I my stomach were smaller, but I am working on that with a calorie counting app on the phone.

I made my case a few weeks ago and did not document it with photos as I made it. So, some drawings will be used to recreate steps that would normally have photos.

Step 1: Tools and Materials

I chose to use sheet steel from the outer skin of our old washing machine. This comes with an enamel paint difficult to remove. Burning it off with a propane or MAPP gas torch requires too much heat and causes the metal to distort. It would be better to use a chemical paint remover or a paint removal wheel on a grinder or a drill.

Materials

Sheet steel (about 20 gauge)
1/8 inch steel rod

Tools

Angle head grinder with a cutting wheel, grinding disc, and a flap wheel
Marking pen
Drill or grinder and paint removal wheel
Vise Grip Pliers
Needle nose pliers (for bending the edge band to fit the side pieces)
Clamps to hold pieces until they can be tack welded
Wire feed welder
Dremel tool and a grinding stone

Step 2: Measure the Thickness of the Phone in Its Cover

Measure the thickness of the phone in its protective cover. Allow a little extra so the phone has the clearance to slide in and out of the case freely. Measure at both ends of the phone, just in case they are not the same.

Step 3:

Cut two pieces (top metal sheet and bottom metal sheet) to cover the top and bottom of the iPhone in its after-market protective cover.* As mentioned before, make these pieces a little larger than the phone to allow the phone to slide smoothly in and out of the finished case and to allow for the thickness of the edge band. I clamped the two pieces together with a Vise-Grip locking pliers and ground the edges so they would be exactly even.

The edge band must be a uniform width along its entire length. The length needed to cover the three side of the iPhone case is about ten inches.

After the top metal sheet and the bottom metal sheet are ready, bend the edge band to fit the curved corners of the top and bottom metal sheets.

*Users of iPhones are encouraged to add a non-metallic protective cover to their phones because the shiny band around the phone is its antenna. Holding the phone in the user's bare hands blocks much of the signal. Complaints about dropped calls and low signal were solved when Apple gave customers a plastic protective cover.

I wondered if my steel case would block tower signals, but the case is open on the top and I have had no problems getting the phone to ring when someone calls. I have used my new phone case in several states already, and it has worked fine everywhere.

Step 4: Assembly of the Main Pieces

Weld the top and bottom sheets of metal to the edge band. See the lines where the pieces meet. These lines became the weld seams. If the side sheets are welded to the edge band so the edge band acts as a spacer, the sizing on the case will not change during welding. I made a first attempt at making a phone casse with a slightly different design. Although I had tack welded the pieces together and checked the fit, the pieces moved closer together during the heating and cooling of welding so that my phone no longer fit inside the case.

My welder is a flux core wire feed welder, so I cannot dial down the heat intensity enough to make a continuous bead without burning holes in the sheet steel. I made a series of tack welds. I kept moving the area where I was welding to prevent so much heat from building up in one area that there might be danger of burning a hole through the sheet metal.

After welding was completed, I ground the welds as smooth as possible without removing the metal sheet. Where there were pitted areas, I cleaned the area and filled them with the welder. That meant more grinding to make those fill welds smooth, too.

Step 5: The Belt Loop

I used 1/8 inch steel rod to make a sturdy belt loop and welded it to the back of the phone case. The difficult part is welding the thicker rod to the thinner sheet steel without burning a hole in the sheet steel. I began the arc on the thin metal and fairly quickly moved the arc to the thicker rod. The short piece near my thumb that runs between the bottom of the belt loop and the metal case keeps the phone case from slipping off of my belt when I am wearing it, as while sitting in a car or on an airplane.

The process for bending the belt loop is described in this Instructable.

See the second photo. It shows a bend I added to the belt loop (yellow line) compared to where the belt normally contacts the belt loop (blue line). The purpose of this bend will be explained in step 8.

Step 6: Cut the Finger Opening

I raise my phone for removal from its case by pushing it upward with my finger in an opening I cut in the phone case. A variety of methods could be used to make this opening. These would include a Dremel tool with a cutter wheel and finishing with a grinding stone. I put a metal cutting wheel on the shaft of my radial arm saw and ground away metal until I had an opening about the size and shape I wanted. I did also use a Dremel with a grinding stone to remove burrs and to fine tune the curved portion of the opening.

Step 7: Polish the Case

I just recently began to use a flap disc on some of my metal projects and am very pleased with the soft swirls that appear in the surface of the metal. I remind myself not to grind too much in any one area so the metal sheet does not become too thin.

Step 8: Safely Removing the Phone From Its Case

The extra bend in the belt loop (yellow line in second photo from step 5) causes the top of the phone case to tip outward from my waist when I slide the phone case upward on my belt. The angle outward would be about what is shown in the photo, even if I did not have my hand on the phone case. This outward tipping gives me better clearance from my waist and my clothing. The photo shows the phone case tipped outward. Go to the next step for the next part of removing the phone from the case.

Step 9: Raise the Phone in Its Holder

Insert the third finger in the opening at the bottom front of the phone case and push the phone upward. My phone has a soft rubber case. If I keep my finger inside the case as near to my body as possible, the soft rubber case is less likely to separate from the phone and add resistance to removing the phone.

Step 10: Grasp the Top of the Phone

While holding the phone upward in the case as shown in the previous step, grasp the exposed top part of the phone between the thumb and the base joint for the first finger. Pull the phone the rest of the way from the case.

Putting the phone back into the case is a matter of tipping the case outward as shown in step 3, gently inserting about a half of an inch of the phone into the case, checking to be certain both ends of the phone are inside the case and the phone is aligned with the case's opening (not cocked with one corner of the phone in and one not really in), and pushing the phone the rest of the way down into the case.

Practice helps to learn to remove and insert the phone safely and smoothly. I like to be cautious. I do not want to drop the phone because I was too hasty. The upper corners of my case are somewhat sharp, and I did get a scratch once when I was fumbling to remove my phone from its case while belted into an automobile, but, under normal usage the case's corners are not a problem.

After using this phone case for several weeks, I found little things about the fit and appearance I wished had been better. A couple of times I have done a little touch up surgery with my welder and grinder. (These photos were made before those improvements.) If at first you do not get exactly what you wanted, you can tweak the phone case and no one but you will ever know.

The phone case could be finished with a clear coat, or even powder coated. I am leaving mine unfinished (other than the swirls from the flap wheel) because I believe daily brushes with my hand and my clothing will keep the metal bright.