working with high speed steel

Yeah. Try it and see.

First, jointer blades are traditionally D2, not HSS. Most of your problem is the same either way, however.

This is pure guess, based on playing a bit with these steels but not doing quite what you have in mind: I think you'll be able to get away with it. If you work quickly, you should be able to wrap a wet rag around the part you don't want to wreck and keep the temper. Watch out for the steam.

The "mess"of re-heat-treating HSS is mostly a matter of trying to restore its high-temperature hardness. But you don't have to do that. If you did have to re-treat it, you might get away with a simple heat-and-quench and not worry about the solution hardening part. The transition temperature is a bit higher than for carbon steel but, if you aren't restoring the high-temp capability, you don't have to sweat getting it hot enough to put the carbides back into solution.

I think. I don't really know if leaving them in their precipitated state would hamper bending the tangs with heat, but I don't think so.

You may get lucky and find someone here who really knows the answer but it's a pretty unusual thing you're doing. And, again, it's more likely D2 than HSS. That doesn't present as much of a carbide issue.

Do you have a scrap of the blade left to give it a test? If so, that's your best bet.

-- Ed Huntress

I have had no luck bending hardened HSS. I wanted to put a slight hook on the end of 1/8", 3/16", and 1/4" square tool bits. I bought the tool bits from ENCO, so the quality was questionable. I heated with an Oxy/Acet torch. In all cases, I could melt the edges or the bulk, however when I went to bend the material, it was very firm, and fractured along large boundaries. (looked like a hard cheese). YMMV.

Dave J.

Good input. I have had very good results silverbrazing HSS, both to HSS and to mild steel.

Ed, I've never seen a HCS jointer knife before. Perhaps they were common "way back when" but everything's HSS or carbide (insert or brazed) these days.

Regards,

Robin

As others will mention, HSS can be brazed and/or silver soldered to any other braze-compatible material without sacrificing the ability for the HSS to be sharpened, and hold a sharpened edge (essentially no loss of hardness).

I'm fairly certain of this, as I've mounted HSS to steel with a MAPP torch, then sharpened the HSS for use in turning steel workpieces in a lathe, and as a flycutter for milling steel.

As someone mentioned, you won't be able to bend HSS, not even with torch heat.

If a small feature (handle tang/stem, for example) is created by grinding away a portion of the HSS piece, I would expect a small feature to be too fragile for use as a woodworking tool. HSS doesn't anneal like common high carbon steels do.

Small cross-sections of HSS are fairly weak, and very likely to break when side pressure is applied (snap like a drill that's flexed sideways).

I'm not sure that I've seen the type of spoke shave you're referring to, except possibly a quick view of one on The Woodright's Shop on PBS.

I have seen a lot of draw planes, and they seem to be about as common as dirt (here in the northeast US), it seems many of 'em are just bought for wall hangers, to display rather than to actually use.

Not being able to bend HSS while hot, is exactly why it is called "high speed steel".

i

Well, I just took a look online and it looks like most of the standard jointer knives are still D2, with HSS as an extra-cost option. The last factory set I bought for my Delta 6" jointer was D2.

-- Ed Huntress

is there an easy way to distinguish them apart in my woodworking shop? and if it is D2 am I likely to be able to spot anneal and bend?

Only up to around 1,000 or 1,100 deg. F, Iggy. That's the limit. The precipitation hardening starts to break down beyond that temperature. That's a very dull red, hard to see in bright light.

Someone mentioned that HSS requires a special anneal, which is true, but HSS is forged to make various cutting tools, commercially, so there must be some way to do it.

-- Ed Huntress

Not that I know of. I've never tried to distinguish them with a spark test -- they both make fat sparks like a lot of high-alloy tool steels -- but I was never looking for the difference, either. Maybe someone here, or on alt.machines.cnc, can tell you how to spark-test them.

My first thought was that it should, theoretically, be easier to forge, and a quick look online shows that both D2 and HSS are forged in commercial operations. But knife makers and other small-scale operators seem to be saying that both are difficult to forge without shattering them.

Since both D2 and HSS are used in custom knife-making, you may want to look for a nest of knife makers and ask there. Someone here should be able to steer you to them, if you're patient enough to wait for one to show up.

I assume you're making an old-style drawknife, right? I have a big one that's been in my family since the late 1800s -- the blade is getting pretty narrow, and I think it's been used to de-hair a few horsehides -- and it has the fine, right-angle tangs you're describing. I also have a short one I made years ago out of an old HSS power hacksaw blade, which I've used a few times for working green wood. I didn't try to make tangs. I just pinned it at both ends to a piece of drill rod with two rivets on each (holes drilled with a carbide-tipped bit in a drill press), and I set the drill rod into maple handles by scorching them into undersize holes in the maple. That's a traditional way to fix handles onto a lot of tools, from gouges and chisels to screwdrivers. Epoxy is good for holding the wooden handles on, too, if you aren't sure about the scorching method. Pinning or silver-brazing some rods onto the blade would save you a lot of trouble if you aren't intent on copying the aesthetics. I just ground flats along an inch and a half or so of the drill rods and fastened them to one side of the blade. It works fine.

BTW, I wore out a pretty good aluminum oxide wheel grinding the teeth off of the hacksaw blade, and it made a heck of a mess of grinding dust all over the shop. I suspect that a silicon carbide wheel would have stood up better.

-- Ed Huntress

not a drawknife, a spokeshave. I suppose it falls somewhere between a drawknife and a plane.

Right on the D2, (I don't think it can be bent successfully at any heat without a draw first). But I could be wrong (I think it is available in drawn welding wire).

My notions about HSS is that you have "one chance with it after the melt". Pretty sure forging is done at a lower temp than the Ac3 temp where HSS does its voodoo.

Matt

The magic of this type of tool isn't its hot or cold hardness but its toughness. Good cutlery, wood saws, etc. benefit from being easy to sharpen and hone.

Matt

On Sun, 30 Nov 2008 22:58:23 -0800 (PST), the infamous snipped-for-privacy@yahoo.com scrawled the following:

I bought a Ron Hock iron from Spokeshave way back when. He inserted studs for knurled nuts to adjust the height. I really prefer that to the ol' "beat on the tang" adjustment system. ;) The irons are made from a high carbon steel. Hock also uses A2 for plane blade styles.

(Hi, Spokie!)

G'luck in your endeavor.

-- The only difference between a rut and a grave...is in their dimensions. -- Ellen Glasglow

There are plenty of materials that are difficult to bend at high temperatures but make lousy cutting tools. High speed steel's main virtue is that holds an edge at high temperatures. The two are related, but not the same thing.

This aspect of HSS is often misunderstood and misrepresented by the uninitiated.

So many folks still regard getting HSS hot as being detrimental to the cutting tool, when it's not.

The other point which is an old bad habit repeated thru the years/generations is that dipping hot cutting tools into water to cool them off is beneficial. Well, it is beneficial for not turning fingertips into leather, but otherwise not good for the cutting tool (not so bad at moderately warm/low heat, but definitely not good at high heat, color changing ranges).

I usually gather up several cutting tools, and/or some new blanks for shaping, and set each one aside on a steel plate to cool, then pick up a cool one to handle and grind next. This works out really well, for me anyway.

I don't suffer burned fingertips anymore, since making these tool holders for grinding square HSS lathe cutting tools:

With a hex wrench and a parallel-jaw plier, I can swap out HSS cutting tools quickly for grinding small batches in one session. Using two of these holders makes a session go fairly quickly for 2 different sized cutting tools.

so really my question is about spot annealing HSS and what that does to the immediately adjacent metal. can I get HSS hot enough to bend with my OA torch, and what will I have when it cools?

In case you missed the earlier replies, heating the piece (or parts of it) will not anneal it to a softer more manageable state if the piece is actually HSS. The factory methods of annealing HSS are too complex to duplicate.

The piece may anneal if it is another type of tool steel, but bending with a torch may still not lead to good results.

One reply suggested that you reconsider your method of mating/attaching the blade to the wood part.

Another suggested that you locate some high carbon steel to use as a blade, and that it is the traditional blade material.

Another suggested that you braze or silver solder some features onto your existing piece, to make mounting/securing the blade to the wood section.

see below..

Yeah. Try it and see.

First, jointer blades are traditionally D2, not HSS. Most of your problem is the same either way, however.

This is pure guess, based on playing a bit with these steels but not doing quite what you have in mind: I think you'll be able to get away with it. If you work quickly, you should be able to wrap a wet rag around the part you don't want to wreck and keep the temper. Watch out for the steam.

The "mess"of re-heat-treating HSS is mostly a matter of trying to restore its high-temperature hardness. But you don't have to do that. If you did have to re-treat it, you might get away with a simple heat-and-quench and not worry about the solution hardening part. The transition temperature is a bit higher than for carbon steel but, if you aren't restoring the high-temp capability, you don't have to sweat getting it hot enough to put the carbides back into solution.

I think. I don't really know if leaving them in their precipitated state would hamper bending the tangs with heat, but I don't think so.

You may get lucky and find someone here who really knows the answer but it's a pretty unusual thing you're doing. And, again, it's more likely D2 than HSS. That doesn't present as much of a carbide issue.

Do you have a scrap of the blade left to give it a test? If so, that's your best bet.

-- Ed Huntress

==================

Not that I know of. I've never tried to distinguish them with a spark test -- they both make fat sparks like a lot of high-alloy tool steels -- but I was never looking for the difference, either. Maybe someone here, or on alt.machines.cnc, can tell you how to spark-test them.

My first thought was that it should, theoretically, be easier to forge, and a quick look online shows that both D2 and HSS are forged in commercial operations. But knife makers and other small-scale operators seem to be saying that both are difficult to forge without shattering them.

Since both D2 and HSS are used in custom knife-making, you may want to look for a nest of knife makers and ask there. Someone here should be able to steer you to them, if you're patient enough to wait for one to show up.

I assume you're making an old-style drawknife, right? I have a big one that's been in my family since the late 1800s -- the blade is getting pretty narrow, and I think it's been used to de-hair a few horsehides -- and it has the fine, right-angle tangs you're describing. I also have a short one I made years ago out of an old HSS power hacksaw blade, which I've used a few times for working green wood. I didn't try to make tangs. I just pinned it at both ends to a piece of drill rod with two rivets on each (holes drilled with a carbide-tipped bit in a drill press), and I set the drill rod into maple handles by scorching them into undersize holes in the maple. That's a traditional way to fix handles onto a lot of tools, from gouges and chisels to screwdrivers. Epoxy is good for holding the wooden handles on, too, if you aren't sure about the scorching method. Pinning or silver-brazing some rods onto the blade would save you a lot of trouble if you aren't intent on copying the aesthetics. I just ground flats along an inch and a half or so of the drill rods and fastened them to one side of the blade. It works fine.

BTW, I wore out a pretty good aluminum oxide wheel grinding the teeth off of the hacksaw blade, and it made a heck of a mess of grinding dust all over the shop. I suspect that a silicon carbide wheel would have stood up better.

-- Ed Huntress

=====================

I bought a Ron Hock iron from Spokeshave way back when. He inserted studs for knurled nuts to adjust the height. I really prefer that to the ol' "beat on the tang" adjustment system. ;) The irons are made from a high carbon steel. Hock also uses A2 for plane blade styles.

(Hi, Spokie!)

G'luck in your endeavor.

======================

Right on the D2, (I don't think it can be bent successfully at any heat without a draw first). But I could be wrong (I think it is available in drawn welding wire).

My notions about HSS is that you have "one chance with it after the melt". Pretty sure forging is done at a lower temp than the Ac3 temp where HSS does its voodoo.

Matt

=====================

I have had no luck bending hardened HSS. I wanted to put a slight hook on the end of 1/8", 3/16", and 1/4" square tool bits. I bought the tool bits from ENCO, so the quality was questionable. I heated with an Oxy/Acet torch. In all cases, I could melt the edges or the bulk, however when I went to bend the material, it was very firm, and fractured along large boundaries. (looked like a hard cheese). YMMV.

Dave J.

===================

Good input. I have had very good results silverbrazing HSS, both to HSS and to mild steel.

==================

As others will mention, HSS can be brazed and/or silver soldered to any other braze-compatible material without sacrificing the ability for the HSS to be sharpened, and hold a sharpened edge (essentially no loss of hardness).

I'm fairly certain of this, as I've mounted HSS to steel with a MAPP torch, then sharpened the HSS for use in turning steel workpieces in a lathe, and as a flycutter for milling steel.

As someone mentioned, you won't be able to bend HSS, not even with torch heat.

If a small feature (handle tang/stem, for example) is created by grinding away a portion of the HSS piece, I would expect a small feature to be too fragile for use as a woodworking tool. HSS doesn't anneal like common high carbon steels do.

Small cross-sections of HSS are fairly weak, and very likely to break when side pressure is applied (snap like a drill that's flexed sideways).

I'm not sure that I've seen the type of spoke shave you're referring to, except possibly a quick view of one on The Woodright's Shop on PBS.

I have seen a lot of draw planes, and they seem to be about as common as dirt (here in the northeast US), it seems many of 'em are just bought for wall hangers, to display rather than to actually use.

Metal lathes use high speed steel from simple to exotic. It comes pre-hardened. One cold grinds the cutters and hand laps on India stone and the like.

It resists movement. Mart>> Not being able to bend HSS while hot, is exactly why it is called