Drill Bits - What is best?
- Thread starter Egbert
- Start date
whistlepig
Elite Member
I think titanium is a coating as is black oxide. When the coating wears off so does the advantage. High Speed steel for general purpose work in steel. Cobalt is much harder than high speed steel, will hold an edge longer, but is brittle and breaks easily, and is more expensive. High speed steel for me.
mikehaugen
Elite Member
yes, hss and cobalt are materials, the others are coatings. Cobalt is good if you are using it in a fixture in a drill press or or mill, for hand drilling stick to hss. Titanium coating is overrated IMHO, black oxide finish is fine... unless you are drilling aluminum- then it sticks and gums up. To be honest, I usually just prefer plain "bright" finish hss bits. Money is better spent on quality bits than on finishes. Try to buy Cleveland or Chicago-Latrobe (there are probably other good ones too).
If you want to buy cobalt, be aware that there are different grades, IIRC m35 is 5% cobalt and m42 is 8% cobalt.
If you want to buy cobalt, be aware that there are different grades, IIRC m35 is 5% cobalt and m42 is 8% cobalt.
Kyle_in_Tex
Super Star Member
The best basic drill bits are Chicago-Latrobe, cobalt M42, split point. Nachi makes an excellent drill in a black oxide coating with split point.
There are better, more expensive drills for different materials.
There are better, more expensive drills for different materials.
AlanB
Elite Member
I run cobalts at my home shop for all the common sizes, such as 3/16, 1/4 etc. Generally have HSS for the other 160 or so sizes.
At work (aircraft Sheetmetal guy) pretty much all cobalt.
Drill bits are a tool like any other, and in short, you get what you pay for. Sometimes it is money well spent to have quality, and sometimes, especially for limited use, the cheaper ones are fine. Even at that, I like to still buy quality.
At work (aircraft Sheetmetal guy) pretty much all cobalt.
Drill bits are a tool like any other, and in short, you get what you pay for. Sometimes it is money well spent to have quality, and sometimes, especially for limited use, the cheaper ones are fine. Even at that, I like to still buy quality.
whistlepig
Elite Member
Conditions have to be right for cobalt. Proper speeds, feeds, and rigidity. Putting a cobalt drill bit in a cordless drill will be sure to disappoint. Cleveland, in my opinion, makes the best HSS drill bits.
2TonCommon
Member
High speed for general use @ 118 degree drill point angle most steels @ 135 degree drill point angle for most nonferrous metals (brass, bronze, copper, aluminum, etc.).
Cobalt for any Stainless Steel and Cast Iron (you can thank me later).
Solid Carbide (not masonry style blade tipped) for the rare instance you want to drill into ballistic steel like HY100 or similar.
And.... most importantly.... the correct lubricant for the type of material you're drilling into.
Cobalt for any Stainless Steel and Cast Iron (you can thank me later).
Solid Carbide (not masonry style blade tipped) for the rare instance you want to drill into ballistic steel like HY100 or similar.
And.... most importantly.... the correct lubricant for the type of material you're drilling into.
whistlepig
Elite Member
Agreed. A good cutting oil will greatly extend the life of your drill bits when cutting metal.
mostly_gas
Super Member
With the correct grinding wheels. We had different wheel for HSS and Carbide.