Drill Stainless Steel The Easy Way
To Drilling Stainless Steel
How to drill into stainless steel is a commonly asked question and for many drilling stainless steel can
be a daunting task. However it can be done easily and efficiently if you follow some simple steps and
consider the following questions which all amount to keeping the drilling surface temperature as low as
Step 1. Drill bit
When drilling into stainless steel the choice of drill bit will ultimately determine how successful you will
be. Cobalt drill bits are considered the best option due to their ability to withstand the high
temperatures created when drilling harder metals.
Step 2. Speed
Many people have a tendency to drill at as high a speed as possible assuming that the faster the drill bit
is turning the quicker it will drill the hole. This is a big mistake, particularly when drilling stainless
steel. Stainless steel is not the hardest of metals in its natural form, however as pointed out by Chip
Lawson in his piece ‘Know How: Drilling Stainless Steel’, stainless steel will ‘work harden’ fairly quickly
when heated, and one sure way to increase heat is to drill fast. Once the stainless steel is work hardened
it will become very difficult to drill.
There are many drill bit speed charts available quoting revolutions per minute, in reality not too many
people will be able to relate to these figures. Our advice would be to drill at as slow a speed as your
power drill will allow.
Step 3. Pressure
Another misconception is that maximum pressure will result in maximum results. Excessive pressure will
have the same effect as drilling at a high speed, it will cause unwanted heat build up. The best approach
is to start off with a light pressure increasing slowly until you achieve nice spiral cuts coming from the
cutting face. Once achieved do not exceed required pressure.
Step 4. Lubricant
It may seem obvious to some that when two metal surfaces are moving against each other under
pressure that lubrication is necessary. However many will drill metal without any form of lubrication. A
good drilling Lubricant will reduce the friction and assist in controlling temperature build up. There are
many types ofdrilling lubricant available including oils, sprays and pastes. Our advice would be to use
one rather than not using any.
Step 5. Take a break…
Even with a slow speed, reduced pressure and good lubrication heat build up is inevitable when drilling
stainless. It is important therefore to stop drilling from time to time to allow the drill bit to cool down.
We would recommend you do not drill for longer that 30 seconds without taking a break. As Allfasteners
the drill bit size the faster the heat build up will be so this time should be reduced for larger drill bit