FHS Design Engineering





How to Drill Metal

Drilling metal isn’t a really tricky operation, but there are certainly some precautions you need to take. The first step in any venture lies in knowing exactly what you need to do. Drilling metal requires the right drill bit, the right measurements and the right amount of patience.


Things You'll need

- Safety glasses
- Drill
- Drill bits
- Ruler
- Pencil
- Small nail
- Hammer



1. Secure the piece that you want to drill with a vise or a clamp so it can’t slip. You’ll need both of your hands to keep the drill steady as well, since you’ll be drilling slowly.


2. Measure exactly where you need to drill and mark it so you can see it. If you need to find a center point, measure your length and mark the half way point on all four sides of the piece and draw a straight line across the center from top to bottom and from side to side. Your center point is where the two lines intersect. Use a tiny nail and a sharp blow with a small hammer to mark it.


3. Hold the drill steady and drill slowly. It’s very important that the drill not slip, because metal and metal surfaces can buckle and mar easily. With a hard metal like stainless steel, you need to drill slowly and lift the drill bit up quickly when you’ve cut as much as you want. Never drill any metals at higher than medium speed for the best and safest results.


4. Choose the right drill bit for the job If you’re drilling a soft metal like aluminum, brass and copper. However, you need to speed it up a bit because soft metals can produce swarf (fine metal shavings) buildup that will adhere to the drill bit and ruin the cut.


5. Use a graduated bit on softer products to save time and money. A cone drill bit or a step drill bit is also a useful bit for soft metals. It’s designed to cut various sized holes in thin sheet metals. The cone can be smooth, or it can have graduated steps on it. You can use one of these to cut a whole range of sizes of holes by drilling to the diameter you want which saves the time and cost of switching drill bits. If you can’t use a cone or step drill bit, start with a small bit and gradually increase the size until you get the size you’re looking for.


6. Get harder bits for harder jobs. Coated high-speed steel (HSS) drill bits are coated with a special aluminum nitride are good for most metals but avoid using them on aluminum as the metal tends to become welded to the bit, making clean drilling impossible. These aren’t the cheapest drill bits, but there are cheap imitations. They should be gold colored, but some are cheap bits with gold put on top to look like the expensive ones.


7. Drill harder metals like stainless with a cobalt bit. These are harder than HSS bits and will work best with heavier metals. You can also choose the C1150 or D200 for stainless, which are variations on the same theme. They look about the same but are a little bit tougher. Check out the package to tell the difference. Use a solid carbide bit when you want to cut something like hard steel, because this is a really sturdy bit.


8. Take your time to do the job safely and cleanly. If you don't use caution when drilling metal, you will end up with holes that are out of round, and there's no fixing that problem. Do it nice and easy to avoid doing it again and paying for your materials twice.