Today I cut a reamer in half...

[macardoso]

No seriously, I wanted to use a 1/2" reamer on my CNC but it only has 9.5" of useable Z travel and the reamer is 7" long. I decided I was going to cut it in half to chuck into a tool holder.

Had no idea how I was going to cut it (I don't use any abrasives in my shop) but I figured id hit it with a hack saw and see how hard it was. To my amazement, the hacksaw bit and cut right through in under a minute.

I'm confused... it is a high quality Morse brand HSS reamer. How was I able to cut it? Isn't HSS hard as all get out? Are tool shanks annealed? Is only the cutting end hardened? Is my hacksaw made of kryptonite?

 

[Superburban]

Yes.

 

[Superburban]

No, seriously, that is a good question. I would not have even thought of trying a hacksaw, or basically any type of toothed saw. Even a quick Google search, only yields people using abrasives.

Interesting, look forward to seeing others respond.

 

[GL]

Interesting question . At first I thought you might be cutting in half lengthwise, which would have been a neat trick, why doesn't matter sometimes. The reamer end is hard, shanks not so much - no need really. Lathe tool blanks can be cut by saw too. Will let your purchasing experience of hack saws answer your kryptonite question, maybe you got a great deal at an auction?

 

[macardoso]

At first I thought you might be cutting in half lengthwise, which would have been a neat trick, why doesn't matter sometimes.

That would be a real pain!

I just would have thought that HSS would be provided in pre-hardened and ground steel blanks which would get cut on a CNC grinder. Wouldn't expect them to only be hard on one end. But I guess I learned something.

 

[mikey]

I'm not sure about how much of a reamer is fully hardened but I suspect just the cutter head part is. The shank of a chucking reamer is expected to bend and a hardened shank would not allow that so it may be that they anneal the shank?

 

[Downunder Bob]

Perhaps a photo of it after the cut might help. I guess you didn't think to take a photo before the cut.

 

[macardoso]

Perhaps a photo of it after the cut might help. I guess you didn't think to take a photo before the cut.

I'll take one tonight. Imagine the smooth shank cut about half was between the end of the tool and the start of the cutting flutes. It was soft enough to stamp the cutter size onto the new end of shank. Had no issue cleaning it up with a file. Felt like a really nice cutting mild steel. Weird.

 

[Bob Korves]

After shortening the shank, it is even more important that you check runout when mounted. If not concentric, you may have trouble with only one side of the reamer cutting due to the incresased stiffness, and also cutting holes larger than expected.

 

[macardoso]

After shortening the shank, it is even more important that you check runout when mounted. If not concentric, you may have trouble with only one side of the reamer cutting due to the incresased stiffness, and also cutting holes larger than expected.

I'm learning a lot today about how reamers actually work! Thanks for the advice Bob.