Reddish-purple coated drill bits - Makita

[slotard]

Today I bought some tools from an elderly couple, including a set of drill bits. The bits don't all match, but some of them have a reddish-purple coating on them and are marked MAKITA HS USA. I'd never seen purple drill bits before, are they anything special or just junk?

http://sphotos-a.**.fbcdn.net/hphotos-prn1/69110_10100603802082645_1473486545_n.jpg

 

[slotard]

anyone?

 

[5lima30]

I've got some left from a set I bought 10-12 yrs ago at Sams. They were part of those drill/ driver bet sets that came in a blue plastic case. They are great bits and better than most you will get these days! As I recall the set was about 25-30$. I wish I could but another set!

 

[larry_g]

That sure looks like a thin coat of gun bluing on there. Does it scratch off? Probably a good bit, colored to attract, or prevent rust. Use them till they prove they are good or bad.

lg
no neat sig line

 

[Monte]

cobalt ?

 

[woody 73]

I am thinking it must be some kind of special treatment from the factory nothing to worry about.

 

[acdeucey]

About 10 to 15 years ago I purchased a 7-piece set of those that came in a plastic case along with a "Stubby" Finder/Driver and six bits.

The description in the case reads: "Makita UltraFast Drilling Bits. Advanced split point design penetrates on contact."

I haven't used them that much, (I have other drill bits.) but they worked well when I did use them.

Don

 

[fordbroncodave]

the coloring is more then likely a metal heat treatment for longevity and stiffness of the bits.

the bits that have not had heat treatment tend to just bend if they get leaned on rather then snap and fly half way across the room.

 

[fordbroncodave]

i think the irwin bits are a prime example of this

 

[beerdog]

all twist drill bits are heat treated and hardened. None are dead soft steel. That said, there is a big performance difference between brands and surface treatments. Since they say makita they are probably cheap drills that came with a makita drill.