# Drilling Silver Steel. What kind of drill bits are required?



## 12345Peter (16 Jun 2012)

I am hoping to make a shaft to hold a 13mm round carbide cutter and was about to order some drill bits, but I have found that there are several types and wondered if I need special bits to drill a hole into Silver Steel ready for tapping?

Regards


----------



## Finial (16 Jun 2012)

I'm no expert, but I would use a normal HSS twist bit and run the drill fairly slow and keep the pressure on. Silver steel is tough stuff but it works ok. Make sure the tap is sharp and that the hole is a little bigger than the normal size for that tap, or it may break.


----------



## paulm (16 Jun 2012)

As Terry says, normal hss should be fine.

Cheers, Paul


----------



## 12345Peter (16 Jun 2012)

Finial":32n7lqzq said:


> I'm no expert, but I would use a normal HSS twist bit and run the drill fairly slow and keep the pressure on. Silver steel is tough stuff but it works ok. Make sure the tap is sharp and that the hole is a little bigger than the normal size for that tap, or it may break.



The tap size is 4mm and I was going to get 3.3mm drill bits. If I was to use 3.5mm drill bits would that be enough clearance without leaving the thread weakened?

Regards


----------



## TheTiddles (16 Jun 2012)

Use the size drill bit that should be used for the tap. Silver steel isn't hard, but is hardenable. Are you drilling into the end or onto the cylinder surface?

Aidan


----------



## 12345Peter (16 Jun 2012)

TheTiddles":249fkr3f said:


> Use the size drill bit that should be used for the tap. Silver steel isn't hard, but is hardenable. Are you drilling into the end or onto the cylinder surface?
> 
> Aidan



I will be grinding a flat on the cylinder surface and drilling through the flat not into the "end grain" so to speak.

Regards


----------



## jasonB (17 Jun 2012)

Make sure you grind that face absolutely flat, carbide inserts are very brittle so if you tighten it onto anything but a flat surface its likely to fracture either straight away or when under load.

Standard HSS drill will be fine and 3.3mm size, use some form of cutting fluid, oil will do if nothing else is available.

J


----------



## Finial (17 Jun 2012)

A slightly oversize hole makes tapping easier but of course weakens the thread. For a job like this, where there is not much strain on the thread, that wouldn't matter too much. But the recommended size is best if the tap goes in OK.


----------



## Harbo (17 Jun 2012)

Check the drill diam. - I've found some to be smaller than stated and it makes tapping very difficult.

Rod


----------



## 12345Peter (17 Jun 2012)

Thank you everyone, I will try the 3.3mm drill and see how it goes. I will also make sure that I grind it as flat as I can.

Thanks again.
regards


----------



## woodyturner (17 Jun 2012)

I have just made these and the one with the red handle is the one I user silver steel any HSS drill will cut through it and you will need to use the 3.3mm drill bit for 4mm thread good luck


----------



## 12345Peter (18 Jun 2012)

woodyturner":ls059yxv said:


> I have just made these and the one with the red handle is the one I user silver steel any HSS drill will cut through it and you will need to use the 3.3mm drill bit for 4mm thread good luck



Thanks, how good were the carboloy inserts?

Regards


----------



## woodyturner (18 Jun 2012)

They will never replace the bowl gouge for speed I started this as an experiment for a friend who couldn't sharpen tools to save his life and these are so easy to sharpen just lay them flat on a diamond stone and they do work I have made three different sizes two for deep hollow turning on end grain for were the rolly muno wont reach and they work a treat on that


----------



## sometimewoodworker (19 Jun 2012)

TheTiddles":aa5a06yj said:


> Use the size drill bit that should be used for the tap. Silver steel isn't hard, but is hardenable. Are you drilling into the end or onto the cylinder surface?
> 
> Aidan


As Aidan says any tool will do until you harden the silver steel. Many years ago I made T-bar allen keys by drilling into silver steel rod and any drill or file worked.


----------



## 12345Peter (19 Jun 2012)

woodyturner":px76pq17 said:


> They will never replace the bowl gouge for speed I started this as an experiment for a friend who couldn't sharpen tools to save his life and these are so easy to sharpen just lay them flat on a diamond stone and they do work I have made three different sizes two for deep hollow turning on end grain for were the rolly muno wont reach and they work a treat on that



I picked up a used BCT tool with a carbide cutter, from the club I am in, it was a very early Versatool, before Toolpost bought them out and it was my first attempt with a carbide cutter and I found it really aggressive so I know I have to be careful when I start to use one with intent.

Regards


----------

