Are SCLCR boring bars hardened

I have a Glanze 16mm SCLCR boring bar that I need to shorten and slightly reduce the diameter at the non-business end so that I can fit it into my boring head (I couldn't find 5/8" bars anywhere). Before I destroy any tooling, anyone know if these are hardened? OK, I could try the file test but I thought I would ask first in case anyone's tried cutting one. TIA, Martin.

Reply to
Martin Whybrow
Loading thread data ...

They are certainly hardened, but I haven't measured how hard.

I would expect to be able to take a 2.5 thou cut to get to 5/8" with a carbide insert and get a nicer finish than if the steel were annealed.

Shortening it might be more trouble. If it ruined a carbon steel hacksaw blade, I'd use a cutting disk on the surface grinder.

Mark Rand RTFM

Reply to
Mark Rand

Thanks Mark. I haven't got any other indexable turning tools but I do have some brazed carbide tools, not sure if they've got enough of an edge to take a fine cut though. I've had good luck cutting case hardened steel of around

60 -65 HRc with carbide tile hacksaw blades so I may try that to shorten it, otherwise it will have to be an angle grinder as I'm lacking a surface grinder (and the space for one at the moment). Martin
Reply to
Martin Whybrow

I shortened the bar this afternoon; I tried a normal hacksaw and was surprised to find that it cut fairly easily, I was expecting the blade to glance off. Faced off then turned the shank to the required OD with HSS tools. Clearly the Glanze bars are not hardened! Martin

Reply to
Martin Whybrow

There's quite a difference between hardened and "too hard to cut" :-)

I've been doing a fair amount of playing with EN24 recently. Annealed, it's gummy and horrible to cut. Hardened and tempered to 100C You can barely touch it with HSS, the tool bounces off. Tempered to 250C it's hard to cut, but you get a beautiful finish...

Tool holders should be hardened to maximum toughness rather than maximum hardness. This will reduce scarring from clamping screws etc, stop the insert screws from stripping the threads out and increase the ultimate tensile strength of the tool.

A good way to tell if a piece of steel is hardened is to accidentally drop it on the concrete floor. Annealed steel ends up with the corners dented and burred. Hardened and not tempered, you might get two lumps of steel back from the one that you dropped. Hardened and tempered right, you pick it up and dist the concrete dust off it. On second thoughts, that's not a very good method :-(

At lease, that's the way I see it.

Mark Rand RTFM

Reply to
Mark Rand

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.