hss vs carbon steel drill bits

[Kurt Johnson]

With micro drill bits that would be used with a pin vise, which are better bits hss or carbon stellfor our purposes? This is for use with wood.

[PamW]

For wood it doesn't matter....however, hss are better quality.

 

 

Pamela

[bizibilder]

It really doesn't matter which you use.  The major difference between HSS and carbon steel as far as we are concerned is that carbon steel can, if heated sufficiently, lose its sharp edge and can revert to its original "soft" state.  However it would have to be taken to "blue" at around 300°C for this to happen.  HSS can be run red hot and will still hold its edge.

 

It is unlikely that in modelling - even with our small power tools - we would manage that unless we really abused our tools.  If you are burning the timber with a drill bit something is wrong and you may well be in a situation where carbon steel tools would be damaged.

 

Properly hardened and tempered carbon steel is actually harder than HSS - unless allowed to heat up and therefore become soft again.

 

In the US carbon steel suitable for toolmaking is sold as "drill rod" and in the UK it is known as "silver steel".  It is worth noting that carbon steel tools will probably be much cheaper than the equivalent HSS.

[jbshan]

HSS stands for High Speed Steel and is kind of a standard for normal metal working.  You can go up a step to cobalt if the work is harder.

[marktiedens]

Or you can go another step up with titanium bits,although they are generally not available in micro sizes that I know of.

 

Mark

[Maury S]

Keep in mind Carbide bits are very brittle and will not take any side-load without breaking.  I use the carbide bits from Drill Bit City, but only in the drill press.  For the pin vise, only hss bits.  They are more forgiving if your hand is not rock steady.  I tried the carbide bits in my Dremel right angle accessory and just the kick at the start was enough side load to snap them.

Maury