drilling your steel: speed and feed?

[Crayola]

I usually drill my steel, whether thick or thin, at a slow speed with plenty of cutting fluid. After hearing from some other makers, I tried speeding things up. As I continue my experiments, I thought I'd inquire what the rest of you fine makers do!

I drill lots of holes, since I drill holes and then connect the dots with my hack saw to cut out my profiles. Do you go fast or slow? Press hard or light? should I use oen continuous press, or press the bit in and out to help clear chips?

Thanks all!

 

[jhiggins]

Machinery's Handbook has vast tables of feeds and speeds for specific diameters vs materials. After a while it becomes second nature. In my opinion, and please do not take offense, but it sounds like you are beating yourself to death cutting out your knife blanks that way. Are you making your knives strictly by hand? That's a lot of holes!!!

A Harbor Freight bandsaw will save you so much time by cutting to rough size and then you can shape from there.

But to address your question: Yes, a "pecking" style of drilling is most advisable to help clear chips, and allow some fluid to get into the borehole. I usually "spot" the hole to start it, drip a few drops of COol Tool II on it, and then with every peck a few more drops. If the speed is correct you should see fine even curls coming off the bit. Lift a second, and the curls break off. Also, I find that using this method reduces the amount of coolant you need.

 

[peter nap]

Like the man said, it's feel. I almost always have it at the lowest speed though. The curls are the key to a good feed although the harder the steel, the more it chips instead of curls. Some types of steel are more prone to chips like wrought iron. You can still feel the cut though.

I use a lot of cutting oil (kerosene because I'm cheap). If it smokes, peck more often. It's just like grinding, you will know when it feels right!

 

[Luke Smart]

Watch the color of the chips. If you are using a HSS drill bit and the chips are turning yellow to blue, then there is too much heat. HSS can't handle that much heat. Cobalt is better and solid carbide even better. Good luck and happy Drilling!

Luke Smart

 

[mattd]

Jeff,
what kind of blade does the H/F band saw need? Is it the medal cutting band saw or can you get the cheeper 12" band saw? Does H/F sell them? I would really like to get away from drilling 200 holes for every knife.

 

[Guy Thomas]

The inexpensive Harbor Freight or Grizzly bandsaws are great, I wouldn't be without mine now, however with a bit of muscle you can use a hacksaw to profile, without cutting a jillion holes, and you can cut curves fairly well. You can easily use the hacksaw to get to a point where files will do the rest. The band saw just does it WAY easier and faster!

I've discovered that drilling just takes time to learn a feel for it, I burned up many bits to start. I now use cobalt drills (I only buy the size I use), a cutting fluid and the slowest setting on the drill press. The only time I speed things up is when I am using small bits under 1/8". If feed and speed are right you will be rewarded with just one or two nice long curlicues of waste metal. The place to beware the most is when you are breaking through the metal when the hole is nearly finished. I don't burn up bits any more but I still have some things to learn about drilling, especially large, (1/2" and over) holes.

 

[jhiggins]

Originally posted by mattd
Jeff,
what kind of blade does the H/F band saw need? Is it the medal cutting band saw or can you get the cheeper 12" band saw? Does H/F sell them? I would really like to get away from drilling 200 holes for every knife.

Try the Grizzly Model #G1010. It's the very same saw as the HF saw, same price, and you'll have much better customer support. And yes, we are talking about a metal-cutting saw. The real reason folks love this little saw is because it does what the big boys do for very little money. I had mine given to me after it was used and VERY abused. I cleaned it up, put a quality Starrett blade on it, and its been plowing through metal like mad ever since. I have a friend who made a seat for his saw so he can sit comfortably while he is cutting out his blades!

If the above hasn't sold you on this little wonder, then check the following sites. Lots of info there for mods and projects for these machines:

http://www.mini-lathe.com/Bandsaw/Bandsaw.htm

~and~

http://www.tinyisland.com/4x6bsFAQ.html

Hope this helps, bro.