If you look at the machine tool supplier sites they offer tapping fluids that also work well for drilling or sawing. Aluminum and Brass are special problems that have their own fluids.

Drills with the correct angles and surface speeds are highly important in drilling difficult materials. The corner hardware sells twist drills with the expectation that you are going to drill wood or mild steel. MCS sells a wide variety of drills with angles and reliefs for each application. Not saying that you should buy them. Just that their offerings are and education in themselves.

If I had a chioce of cutting oil or water, I would use water every time. As water keeps the drill cooler ,doesn,t give off posionious fumes ,is free ,you can pour it on and it just dries up and try that with oil, what a mess.

The main idea is to keep the drill cool cos heat kills drills. Soluble oil and water is king, but I,ve drilled many times one inch holes in stainless and no problems with just water.Sharp drills also aid in drill bit longevity.

Tap magic ... the old stuff with the 1,1,1 trichloroethane in it. It smelled great, but Nasty stuff though.

Edited September 11, 200916 yr by uncle joe

I've been using ATF and Kerosine 50/50 for several years I believe I found it in the "Bed Side Reader" its cheap and works well

Ten hammers: Well, I can't really agree with your analysis of cutting vs lubricating. Lubricants overcome friction. Cutting tools do not work by friction. No amount of lubricant would make a reamer work as a bearing surface. Bearing surfaces "float" away from each other on a film of oil and depend on a certain amount of surface area. A cutting edge has essentially no surface area and has no problem breaking through that film. Many cutting tools (and drills in particular) have many surfaces that just rub and benefit from lubrication. Many cutting oils have a goodly amount of lubricity to them AND cooling ability.

That's my story, and I'm sticking to it.

Grant has it right. Tools generate trmendous heat and friction at the point of the cut. Especially in carbide tooling cooling is as critical as lubrication. The chips will weld to the tool if cooling is not sufficient. The cooling helps to both prevent welding and promotes chip fracture which allows lower friction.
In my humble experience managing about 50,000 gallons of various coolants in 400+ machines, generating 10,000+# of shavings a day, coolant makes or breaks the tooling, and the parts.

Look for a new or used copy of the Machinery Handbook IE; the machinist's Bible. It covers everything you will want to know.

In general you want the steel chips to remain silver, and not change color with your setup.

Aluminum works good with kerosene. Do Not use 1,1,1, Trichlor products on aluminum! I have seen guys "weld" a 1/2" tap into aluminum after using this stuff. It reacted with the chips, formed a purple smoke, and fused the two together - aboutthatfast.

1,1,1, works fantastic on steel items, as do some brake/carb cleaners. Use in a well ventilated area.

The trick with drilling brass is to put a small flat on the cutting edge. That way the drill bit scrapes the brass, and won't grab and pull itself into the part.

With any drilling let the bit do the work. Put just enough pressure on it to keep a chip formed.

With stainless you do not want to rub the surface, or use a dull bit. SS workhardens extremely fast, and you won't be able to drill it if it does, unless you get a carbide drill, or possibly by reshaping the bit angle.