Cutting HSS Steel

[paul39]

I have a HSS planer blade 12 " L X 2 1/2 " W X 3/8 " thick that I would like to cut in half to make two 1 1/8 +- wide pieces for wood turning tools.

I have more time than $, and do metal / wood working for amusement and sell a few turned things.

My thought is to use a angle grinder with a thin abrasive cut off blade and mount it with a guide and slide the blade under it.

Would I get better abrasive life taking many small cuts, or do the whole depth and feed very slowly?
I also have a junk table saw that could use a larger diameter but thicker abrasive wheel.

Would the heat generated by the abrasive cutting anneal the edge? I could feed a little stream of water and make a really good mess. I'll use a GFCI so as not to get zapped.

I have made one 2 1/4" wide scraper. It took a long time to grind and stays sharp as long as my one high $$ much smaller scraper.

I also have a 4 speed wood band saw, but don't think any reasonably priced blade would cut HSS without annealing.

I don't particularly want to do the rehardening and tempering to make the tools.

I'm open to other suggestions.

Paul

[FlatBeltBob]

a 1/16 " cut off abrasive disc in a 4 1/2 side grinder will do the trick just fine .
layout a square line on the wide side , and do a score cut . then proceed to grind through on the thinner edge , using the score cut as a visual guide .
I would pad a vise with wood blocks and clamp it secure , so you can hold the grinder with both hands . Wear eye protection , gloves and keep out of the line of sparks .
You may need more than 1 disc, but they are pretty cheap .
Ever since I saw them goofs on the chopper show using cut off discs , I have been using a lot more of them for those small hacksaw , torch , tinsnip jobs .
FBBob

[Mcgyver]

I break tool bits (ie use in a boring bar holder) by scoring all the way around using the corner of the bench grinder wheel, wrapping it in a rag (it can shoot shards) and giving it a tap with a hammer while held in the vise, angle grinder sounds like it'd work but go easy and dont get everything red hot

I don't particularly want to do the rehardening and tempering to make the tools.

you wont be able to with hss, it requires a very particular heat treat process the equipment for which aren't in the average home shop or job shop

just break it as described the clean up the end to the shape you want on the bench grinder, hss will take a lot of heat but obviously exercise normal grinding caution

[Mike C.]

Zizz wheel will zip right through it. Don't dally around with light cuts, but don't bog the speed down, either. If you get it slow, it'll just eat up the wheel. Now, seeing you are trying to split this lengthwise... that's a foot of 3/8" HSS you are trying to cut.

You can buy a 1 1/4"x 1/4" HSS Cleveland cutoff tool bit from MSC for $70. Now, that might seem a bit expensive, but you'll probably burn up $30 worth of cutoff wheels and one angle grinder trying to split that planer blade, which is probably worth $100 or so to somebody who needs it.

In addition, you are going to have an ambulance trip to the hospital and some medical expenses when it gets loose and impales itself in your body when the wheel hangs up. You just can't hand feed this on a tablesaw. For one thing, it's going to get rediculously hot, so you simply can't hold it. It's going to have to be set up on a table and fed by screw under the wheel, if you take that approach. You might could do this with a tool&cutter grinder and some cutoff wheels, but I think there's a better way...

Enco has an import 1 1/4"x1/2" rectangular bit, 7" long, for $30.

Also, HSS cannot be annealed without a major effort and a heat treating oven. Try to burn out a HSS tap that has broken off and you'll understand. You can heat it to the point of melting and let it slow cool... only to find it is still just as hard as it was when it broke. High carbon steel tooling can be heated and annealed pretty easily (like getting it too hot while grinding) but not HSS.

[paul39]

Thanks guys. I will go with the angle grinder and thin cut off wheels, with the blade held in a vise.

I will build a kluge like a sliding chop saw to hold the angle grinder.

I have face shield, gloves, sturdy jacket, etc.

I bought the four used blades at auction. Replacement cost $280, I got them for a hair under $30.

HSS lathe tools that size sell for $150 - $200 each.

Paul

[strokersix]

I've found an abrasive chop saw works great for plowing through hardened steel without heating the work. A fresh wheel (full 12" diameter), let it wind up all the way, then cut quickly. Not sure if this helps you or not.

[John in CA]

If I'm seeing this right, even if you do anneal the edge that you're cutting, it won't matter, will it? You won't be cutting wood with the 12" edge, you'll be using the 1-1/8" side, which would retain it's hardness regardless, correct?

[paul39]

Originally Posted by John in CA

If I'm seeing this right, even if you do anneal the edge that you're cutting, it won't matter, will it? You won't be cutting wood with the 12" edge, you'll be using the 1-1/8" side, which would retain it's hardness regardless, correct?

One of them will be a round nose so it might affect a little of the cutting edge. Most of the cutting is done on the left and front of the tool, so I will put the cut side on the right. From what I read above, cutting will not get hot enough to affect the steel.

Paul

[Mike C.]

Enco has a 1 1/4"x1/2"x7" piece of HSS for $30, not $150-200.

http://www.use-enco.com/CGI/INSRIT?P...PARTPG=INLMK32

You could probably sell one of those blades to somebody who needs it and buy dozens of pre-sized HSS bits. You'll figure it out.

Again, you cannot anneal HSS without a heat treat oven.