Drill bits for Metal: black bits or silver? Also speed versus size

Carlow52 · 17-03-2009 01:46PM #1

Was in a fastener shop yesterday where they had a metal box of drill bits: 1mm to 10m in 0.5mm increments, 10 pieces of each = 170 bits. cost 90 euro plus vat

I asked about the quality and was told that,the fact they were silver, as-opposed to black, meant they were very good quality.

Any thoughts?

Also, anyone got a link to a chart for drill speed versus diameter of bit for metal for a drill press.
Thanks

cnocbui · 17-03-2009 01:53PM

The ones which appear gold plated - titanium nitride coated - are possibly a better bet. Personally I would do some research and buy a reputable brand, rather than just take someones word for it.

SpitfireIV · 18-03-2009 04:30AM

Carlow52 wrote: »

I asked about the quality and was told that,the fact they were silver, as-opposed to black, meant they were very good quality.

Any thoughts?

A neighbour of mine gave me a loan of a few larger dia. drill bits recently (12-16mm) to drill metal, and like the bits you mention they were silver, very shiney!

I thought it a little odd, but I think he said they were Makita bits, so good quality. Now, i dont know what make yours are, maybe they are made silver to copy makita?

mp22 · 21-03-2009 09:10PM

hss drill bits 25.4mm bit aprox 200rpm with coolant half the bit size double the rpm
applies to mild steel

Drill bits for Metal: black bits or silver? Also speed versus size

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