2011年3月9日 · I run cobalt drill bits with a 135-degree tip, up to 1/2" diameter, in my drill press through 1/4" and 3/8" mild steel plate pretty routinely without troubles. No pilot hole, but I do use a center punch and a couple of drops of cutting oil with medium speed and normal pressure.

2019年6月1日 · Drill bits are hard to find in a hardware store The HF sets are carbon steel, bad material, wrong sized, bad heat treat, bent, and so on. It’s all confused by marketing bullsiht. They often refer to Titanium, Black oxide, gold something That’s just the coating on the drill You want “Jobber length Twist drill” “HSS High Speed Steel”

2007年12月25日 · I have been using modest priced high speed steel drill bits for years. A drill press will make things much easier, and it was one of the first pieces of equipment that I aquired for the knifeshop. Anyways like you I first started by using a variable speed hand drill. Stand comfortably and first drill a pilot hole 3/32.

2015年2月3日 · Hi all! I am really struggling with finding a good drill bit to use for making pivot holes and pin holes in my knife blanks. I typically use 440C stainless steel, O-1 and 1084. I typically have the need for just two bit sizes, 1/4 and 1/8. I've been buying bits in 12 packs on Amazon. The brand is Irwin and they are cobalt drill bits (allegedly).

1999年4月17日 · Well it may not be much but here is a start for you. Cobalt is often added to "regular steel drilling" bits. It does improve cutting abilty considerably. The common amount of cobalt added is usually 8%. Silicon carbide can be a great cutter but is very brittle and is used in bits to drill very hard steels and also in masonary bits.

2024年4月14日 · It depends on what the tile material is but we use SDS hammer drill and bits 90% of the time, Brittle tile we will drill a small 5/32 first with the SDS or a hammer drill/drill then follow up with a larger Bosch glass/stone in a regular drill. Installing commercial accessories doesn't pay enough to mess around with the diamond core type bits.

2006年7月8日 · your diamond bits will be toast after the first 50/60 rotations. carbide bits with oil or water as a lube. and if you have a drill press run it slow. also can you heat the spot with a torch to anneal it so it doesnt become "work hardened"? if you anneal it you soften the metal. if its in the handle section its not a problem. just dont mess with the hardness of the cutting edge.you can …

2013年12月15日 · If I wanted to drill something like 15V at 64 RC or Rex 121 at 70 RC would carbide bits still cut it adequately? The bit would be run at the recommended speed or very close to it. I would peck at the steel with the bit to keep it from lodging in the steel and breaking.

1998年10月29日 · I bought some Craftsman drill bits that are advertised to drill though hard steels. I tried 1095 and ATS-34 with minimal results. In other words, I only got a couple millimeters depth. Max! I'm using a hand held drill (don't have a drill …

2009年7月13日 · Bingo, that's exactly how I drill my handle materials, whether it's G-10, micarta, carbon fiber, or any other resin based material. I save my cobalt bits for the steel. The cheap Ti coated Dewalt bits I have go through the G-10 and what not just fine.