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Carbide Drill what kind to buy?
- Thread starter Steinmann
- Start date
Nathan the Machinist
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In general, industry uses HSS for most drilling. Carbide is usually used in abrasive applications. This is because carbide, while hard, is relatively brittle so it breaks down and dulls when drilling steel. It has a narrow operational range and responds best in rigid, controlled feed machines such as modern CNC machinery.
You do not want carbide circuit board drills or carbide drills designed for soft abrasive materials. And these represent the majority of carbide drills out there. You want something where the cutting edge is close to 90 deg like you'd see on a straight flute drill. Think "beefy".
You do not want carbide circuit board drills or carbide drills designed for soft abrasive materials. And these represent the majority of carbide drills out there. You want something where the cutting edge is close to 90 deg like you'd see on a straight flute drill. Think "beefy".
Thank you for your explanation; as my English is not so good (especially "slang" English) and to make this story short - do you recommend the std. tip or the diamond shaped one? Cobalt? Or shell I stay with carbide but only a full carbide drill, all through? Thanks again in advance for your effort – Michael.
Nathan the Machinist
KnifeMaker / Machinist / Evil Genius
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Steinmann,
I'm not sure, it depends on what you're drilling. If it is so hard that HSS can not cut it, you need carbide. In that case, you need a carbide drill designed to drill hard steel. Most are designed to drill soft abrasive things like fiberglass.
If you use carbide, you need a rigid setup and a way to control your feedrate. Otherwise you're going to eat up drills.
Generally, it is best to anneal the steel where you're drilling it so a cobalt HSS drill can cut it. I have a full machine shop and I don't try to drill hard steel. Times where it comes up I use a two flute carbide end mill fed in a helix, which requires CNC.
I'm not sure, it depends on what you're drilling. If it is so hard that HSS can not cut it, you need carbide. In that case, you need a carbide drill designed to drill hard steel. Most are designed to drill soft abrasive things like fiberglass.
If you use carbide, you need a rigid setup and a way to control your feedrate. Otherwise you're going to eat up drills.
Generally, it is best to anneal the steel where you're drilling it so a cobalt HSS drill can cut it. I have a full machine shop and I don't try to drill hard steel. Times where it comes up I use a two flute carbide end mill fed in a helix, which requires CNC.
Just buy bits that are designed to drill hardened steel, they should have the tip you need. If there are more than one tip designed to drill hardened steel, either one should work.
I am assuming that you want to make a full tang knife out of a file without having to re heat treat the steel (just temper in the oven) but still be able to drill some pin holes in the handle. Another method to soften the handle part if you have a torch you can submerge the blade portion in water and heat the tang portion with the torch until it turns red. This should soften the area that turned red enough to drill with a regular but still preserve the initial temper in the blade, because it will not get hot enough to soften when it is in water.
I am assuming that you want to make a full tang knife out of a file without having to re heat treat the steel (just temper in the oven) but still be able to drill some pin holes in the handle. Another method to soften the handle part if you have a torch you can submerge the blade portion in water and heat the tang portion with the torch until it turns red. This should soften the area that turned red enough to drill with a regular but still preserve the initial temper in the blade, because it will not get hot enough to soften when it is in water.
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Well, here is my 2 cents worth.
A long time ago, I worked at Pratt & Whitney Aircraft, Machine Repair. I used SOLID carbide drills, some times ans some hardened steel. Of course the drill broke in the free hand drilling mode.Had to send the part out to another dept. to have the remains of the drill, burnt out of the hole.Used carbide TIPPED drills 4 ever after.Did not have 2 much trouble with them breaking after that.
A long time ago, I worked at Pratt & Whitney Aircraft, Machine Repair. I used SOLID carbide drills, some times ans some hardened steel. Of course the drill broke in the free hand drilling mode.Had to send the part out to another dept. to have the remains of the drill, burnt out of the hole.Used carbide TIPPED drills 4 ever after.Did not have 2 much trouble with them breaking after that.