Annular cutter in Mill

[phaxtris]

I don't drill large holes all that often so hopefully they will stay sharp for a while. My drill bits stop at 1", anything larger I just program a CNC circle. I just ordered the Vevor set and will probably use them instead of S&D bits because in comparison they just cut a lot better and require much less power. I would imagine they will remain sharper longer than an equivalent size S&D bit for the same number of inch-holes?

I'm curious

yes they would last much longer and drill much quicker than a twist drill, just dont overspeed the bits and use coolant and you should easily get 100+ holes before they start dulling

 

[mbond]

They might be related or have a common history.....

Cutting a hole in the head with a saw wouldn't be very friendly to the brain underneath. So they probably scraped or carved the piece of skull away.

That's essentially how the metal process works.

Some quick research into what trepanning means in metal work suggests that's probably true. Using the tool to scrape or cut at the edge of the hole. I'm not keen on any practical knowledge of this medical procedure, but if I need to cut a large hole, I have learned something new

 

[djberta]

When I was doing accumulator automation. I had to drill out 22 5/8” holes for the 18 proxy stains and then knock out the 6 to either 7/8” or 1-1/8”. In the main cabinet. mostly stainless so I found Blair rotobroachs. Which are little annular cutters. worked great. I cut the prep time in half versus the guys before me. Guys before would center punch, then step drill to 5/8 and knock out. They burned off boxes of step bits. The purchaser was buying Lenox, Milwaukee, green Lee step bits trying to get ones to last longer. i Showed them the Blair ones, after that I think 100 boxes or more and I went through two kits. All by hand. Later they gave up on having us prep the boxes, farmed the job out, techie didn’t secure the plc Program. They then undercut us and stole the job. It’s kind of funny about a year later I did a service call on one of their boxes. They even used my wire tag layout. Only change was they used way cheaper parts than us.

Sorry memory lane, if anyone wants small annular cutters blair makes them. They work great and with some cutting oil will last a long time. htt ps://www.blairequipment.com/rotabroach-cutters

 

[Larry_C9]

I love those things. They cut a clean smooth fairly accurate hole that almost looks like it has been bored. I use the R8 arbor that is made for them in the mill. It has the spring in it.

 

[CWret]

Here’s my nickel’s worth (can’t do 2 cents worth anymore since we scrapped the penny) - if you don’t have a set of annular cutters you don’t know what you’re missing. They are such a huge improvement over a twist drill for many applications but the twist drill bit still rules the roost. Don’t have a mag drill & not likely to buy one. But annular cutters on the mill are great. The spring is ok but not (IMO) a big plus.