Core Drill Bits

[boilermanc]

Hi all, I have some holes that I need to expand through some pretty tough iron. Doing a little research, the tool for my job is a core drill bit. I have posted a link to example below. I have tried to find a set online but am striking out. I will try to contact HSS but was wondering if someone may know where you can find them? I can find them for masonry but not for metal...

https://en.wikipedia.org/wiki/Drill_bit#mediaviewer/File:HSS_Core_drills.jpg

 

[boilermanc]

Hi all, I have some holes that I need to expand through some pretty tough iron. Doing a little research, the tool for my job is a core drill bit. I have posted a link to example below. I have tried to find a set online but am striking out. I will try to contact HSS but was wondering if someone may know where you can find them? I can find them for masonry but not for metal...

https://en.wikipedia.org/wiki/Drill_bit#mediaviewer/File:HSS_Core_drills.jpg

LOL, so I find out HSS stands for High Speed Steel... learn something new everyday. In any case, anyone know where you can find those type of bits?

 

[boilermanc]

I found some:

http://www.tylertool.com/metal-core-bits/metal-core-bits,default,sc.html

 

[lametec]

Look for annular cutter.

 

[PT Doc]

norseman has bits that will work. you can download the full catalog from the norseman drill website.

 

[PT Doc]

http://www.norsemandrill.com/index.php

what size is the hole now and what size do you need to enlarge it to?

 

[dockterj]

google for "hss core drill". Are you looking for straight shank or morse taper? what is the existing hole diameter and how much larger are you making it?

 

[Murphy4570]

Try Mcmaster-Carr. They have damn near everything.

 

[Under_Pressure]

Any tooling supplier will have them- as mentioned, search for "annular cutter." Travers Tool, McMaster-Carr, MSC, etc. Note that you will need an appropriate arbor in whatever you want to use them in. They are commonly used in mag base drills designed for the purpose, but there are arbors available to use them in other machines with Morse tapers, R8 tapers, etc.

 

[dockterj]

I know the OP linked to a picture of annular cutters but without knowing what he is trying to do they may not be the best solution.

"Core drills" in the context of enlarging holes usually mean three or four flute non center cutting drills that look something like this:
http://www.lidsters.com/3-4-flute-core-drills/

Depending on how thick the material is a unibit might be a good choice too.

 

[Under_Pressure]

I know the OP linked to a picture of annular cutters but without knowing what he is trying to do they may not be the best solution.

"Core drills" in the context of enlarging holes usually mean three or four flute non center cutting drills that look something like this:
http://www.lidsters.com/3-4-flute-core-drills/

Depending on how thick the material is a unibit might be a good choice too.

True- I have to admit I am a bit apprehensive about the whole idea of annular cutters being a tool of choice in the context of enlarging holes. For that to be a good idea, you better be talking about something like a 1/2" hole needing to be 2" instead. Essentially, for this tool to be a good choice, it needs to be a situation where it is irrelevant that the original hole is present at all. Annular cutters require even pressure and loading; in my experience they will not tolerate partial bites of material (like opening up an existing hole by any amount less than the kerf of the cutter). The fact that they are extremely hard but hollow makes them prone to breakage in conditions outside of what they were specifically designed for.

 

[A_Pmech]

How much enlarging needs to be done? A hex shank bridge reamer in an impact gun might be a better solution.

 

[larry_g]

http://www.hougen.com/cutters/cutters_index.html

One source for annular cutters. Note they have special shanks and will need an accessory holder to mount in a mill or drill press.

lg
no neat sig line

 

[wagon]

Those look like Mag Drill bits. They're pricey. Very pricey, but they're tanks.

Norseman is a fantastic drill bit brand, I'll add.

 

[justme-]

Core drills/annular cutters have no arbur or pilot so nothing to center in the existing hole - they are designed to be used with solid anchored drills (mag drills, or for stone/cement, the drill vacuums to the ground and is bolted to it). Ever try using a hole saw without a pilot?

give us some more info on exactly what you're trying to work on and maybe we can offer something safer or more effective.