Welding Tips and Tricks

Sometimes I need to drill larger holes up to 1" which I do with a fairly inexpensive set of Silver and Deming bits in a Rikon 30-212VS bench top VS drill rated for 1". Min drill speed is 150rpm. I am considering the 3 flat Weldon drill adapter and probably a 6-8 cutter set up to 1". I know nothing about these cutters other than watching a few videos and I am wondering about the power requirements compared to an equivalent twist drill in a drill press? The cutter is removing less metal with the slug left in the middle but there are more smaller cutters around the perimeter. Ideally they would take less power and I could possibly step up a bit bigger even? This is strictly hobby use only, not production. After almost a year of lockdowns and restrictions the occasional new "bright and shiney" doesn't hurt either!

Annular cutters work great. They start in size at 1/2”, so between 1/2 and 1” you won’t get 6-8, but you can get them in 1/2, 9/16, 5/8, 3/4 and 1” that I know of.

You need to be aware that they have a cut depth due to the length of their “cup”. And they do create a “plug” like a hole saw. Most have a pilot pin, not twist drill, in the center to prevent the cup walking. That really works well if you have a coolant system as the liquid is delivered via the pilot pin. I use them constantly in my Mag drill or my Knee mill. Drills a machined-like quality hole versus a twist drill finish.

150 RPMs is perfectly fine for them. Torque is their greater need, so slower in a drill press is better.

The most complete set i found was from Milwaukee. 1/2"-1 1/16" in 1/16" increments. 2" depth of cut. I don't have the part number but shouldn't be hard to find. This set is a few years old, I've broken a few and replaced with Walter ones. They do last a good while, I had close to 1,000 holes on the 13/16 specifically before it turned noticeably dull. I tried sharpening it and buggered it completely.

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cj737 wrote:Annular cutters work great. They start in size at 1/2”, so between 1/2 and 1” you won’t get 6-8, but you can get them in 1/2, 9/16, 5/8, 3/4 and 1” that I know of.

You need to be aware that they have a cut depth due to the length of their “cup”. And they do create a “plug” like a hole saw. Most have a pilot pin, not twist drill, in the center to prevent the cup walking. That really works well if you have a coolant system as the liquid is delivered via the pilot pin. I use them constantly in my Mag drill or my Knee mill. Drills a machined-like quality hole versus a twist drill finish.

150 RPMs is perfectly fine for them. Torque is their greater need, so slower in a drill press is better.

Most of the larger holes I drill are for pins so I'll look at kits with oversize also - 11/16 - 13/16 etc included. Talked to a friend who's a hobbiest like me who does some machining and uses these cutters and loves them. I'am fairly confident that if I can easily drill a 1' hole with a 3/16 pilot with a twist drill I can handle these. A coolant system is something to consider.

JayWal wrote:The most complete set i found was from Milwaukee. 1/2"-1 1/16" in 1/16" increments. 2" depth of cut. I don't have the part number but shouldn't be hard to find. This set is a few years old, I've broken a few and replaced with Walter ones. They do last a good while, I had close to 1,000 holes on the 13/16 specifically before it turned noticeably dull. I tried sharpening it and buggered it completely.
Thanks. I will check. Have quite a few Milwaukee tools and cobalt twist drills that work great. Mostly drilling tubing and up to 1/2' stock so thinking 1' at this point. Likely getting a MT2 / Weldon adapter to fit the drill and drop out the chuck instead of the 3 flat adapter thinking there might be less chance of a wobble?
Thanks for the input. Learning experience for me, appreciate the help.