13-03-2022, 07:38 PM
Ok Folks,
An addition to this Boring thread.
Having had to drill lots of 316 Stainless over the years.
rule 1 sharp drill start with pilot drill and open out as needed.
rule 2 slow speed most electric drills run too fast ( I use a decent cordless )
rule 3 use proper cutting fluid
rule 4 use a lot of pressure on the bit
A pillar drill on slow speed is the best tool ( Apart from using a milling machine )
Normal HSS bits are fine to use
Split point drills are very good.
As mentioned before when you cut stainless it work hardens so overheating the work or the drill bit is bad news.
Often you will find a sweet spot of drill speed and pressure and it cuts nicely, you then pull the bit out for a rest and then when you go again it is really hard to start the cut again.
I spend a few years drilling into 25mm round 316 tube to countersink and tap to 4BA I broke less taps using a cordless drill to drive them than with a tap wrench.
An addition to this Boring thread.
Having had to drill lots of 316 Stainless over the years.
rule 1 sharp drill start with pilot drill and open out as needed.
rule 2 slow speed most electric drills run too fast ( I use a decent cordless )
rule 3 use proper cutting fluid
rule 4 use a lot of pressure on the bit
A pillar drill on slow speed is the best tool ( Apart from using a milling machine )
Normal HSS bits are fine to use
Split point drills are very good.
As mentioned before when you cut stainless it work hardens so overheating the work or the drill bit is bad news.
Often you will find a sweet spot of drill speed and pressure and it cuts nicely, you then pull the bit out for a rest and then when you go again it is really hard to start the cut again.
I spend a few years drilling into 25mm round 316 tube to countersink and tap to 4BA I broke less taps using a cordless drill to drive them than with a tap wrench.