Drilling

Related Web Pages

  • Charts – Drill Bits.  Shows, bit sizes in millimeters, inches, fractions and decimals. Also, shows matching B&S wire gauges.

What types of drill bits to use

Question

I am so confused as to which type of drill bits to buy for metal and finding an 18 g bit. Can you point me in the right direction?

Answer

twist-drill  My favorite drill bits are called HSS bits. That translates to: High Speed Steel. You want a steel that is capable of holding onto its sharp edge and HSS does that. It is a very hard steel – which is what we want. I purchase most of my drills from Rio Grande.

There are also titanium coated, cobalt steel drills used for drilling harder metals, as well as many other types. Just stick with the HSS and you can’t go wrong!
For brass, bronze, copper, silver, gold, etc., HSS is great to use. They are often called twist drills.

Drill bits are often measured in inches, millimeters or by drill number. I have a chart on my web page that matches wire gauges to inches, mm’s and drill numbers. It can get very confusing. For an 18g drill bit you’ll need to buy a #60 bit. Other names for the same size: 1.02 mm (rounded up from 1.016mm) or a .0403″. All the same size. I use my drill bit chart to match wire gauge with drill – it helps a lot.

The Rio Grande item # for an 18g bit is: High-Speed Steel Twist Drill, #60, 1.02mm
Item #: 349419 
Sometimes, there aren’t drill bits that match the wire gauge size perfectly. This is evident with 12 and 16 gauge. There is not an exact match so, I use a bit that is slightly smaller or slightly larger. It depends on how tightly I need the wire to fit in the hole. If I need a tight fit, I’ll drill with the smaller bit and wiggle it a little in the hole to open it more – check fit often. If I don’t need a tight fit, I just use the larger bit.

lynx-bur  I have a quick change handpiece that will only accommodate bits with consistently sized shanks: 3/32″ – which are much more costly. With a standard flex shaft handpiece, you can adjust the width of the jaws, for many differently sized shanks so, you don’t have to shell out the big bucks for the 3/32″ shank bits. Dremels have differently sized collets so that you can use tools with different sized shanks – you just switch to a collet that matches the size of your bit’s shank.

bur-life  Always use beeswax or another type of lubricant with your drills. Don’t overheat the bit: drill, let cool for a second, drill, etc. Use lubrication frequently. The lubrication helps to make the drilling smoother (therefore, causing less heat) and it cools (a little) the bit. Stopping to lubricate also cools it down! With thin drill bits, like 18g, 20g, etc., don’t press down hard – they snap really easily. Then, you get to remove the tip from your work before moving on! I have a recipe for steel removal on my website.

When drilling large holes, start by making a divot. Then drill with a smaller drill, moving up to a medium drill and then the final drill.