Shop Made Tools

[Yondering]

Toolguy, how do you harden D2 correctly in the home shop?

[MattiJ]

All the common drill rods can be hardened in a home shop easily with a torch. We're talking A-2, D-2, O-1, S-7, W-1, etc. You do need to know some basic heat treat metallurgy. Getting the temper right is as important as getting the hardening right, but neither is very hard if you know how.

I dont see much need for tempering unless the body is too brittle to hand-hold, all the cutting is done with carbide insert.
I was just worried about the body wearing out but maybe even the hardened 4140 will actually last for 1000 bolts and 30 years.
Cutting oil and lower rpm seems to eliminate scuffing and galling marks on the body. Another solution would be 3-insert version so that workpiece only rides on cutting edges. but the body would be lot more tricky to make and I think its more prone to chatter, possibly leading to chipped inserts.

[Toolguy]

Toolguy, how do you harden D2 correctly in the home shop?

I do it correctly with a programmable heat treat furnace with the parts in stainless steel foil wrap to keep the atmosphere from carburizing the surface when the steel is hot. Not everyone has that luxury. I didn't for many years. You can flame harden the steel with a torch, make sure the size is big enough for some dimensional loss when you decarb. D2 is air hardening, so after it's heated, it will cool in still air on a ventilated cooling rack where the air can circulate evenly. Expanded metal works nicely for the rack. This is for smaller sized parts (punch, chisel, lathe bit, etc.) that are easily torch heated. For something with a large cross section (punch press die blocks, etc.) it should be done professionally.

[bborr01]

My bolt deburring tool body is made of 42CrMo (4140?) steel because thats what I had at hand, hardened after machining.
I was wondering what would be hardest and the most wear-resistant steel that can be hardened with relative ease at home shop?
D2?

I'm not sure how easy it would be to harden it at home but M4 tool steel is about as hard of tool steel as I am aware of. It is also known by the company name Neatro and probably other names too. We used a lot of it for cold forming dies when I was working and it is a bitch to machine but becomes very hard and wear resistant after heat treating. Also known as machinable carbide.

Brian

[MattiJ]

I'm not sure how easy it would be to harden it at home but M4 tool steel is about as hard of tool steel as I am aware of. It is also known by the company name Neatro and probably other names too. We used a lot of it for cold forming dies when I was working and it is a bitch to machine but becomes very hard and wear resistant after heat treating. Also known as machinable carbide.

Brian

Looks to be about as bad or "easy" as any higher grade HSS. Relatively long austenitizing hold at 2200F/1200C. Bit on high side of temperature to reach with every bog standard electric ht oven or gas forge.

[Yondering]

I do it correctly with a programmable heat treat furnace with the parts in stainless steel foil wrap to keep the atmosphere from carburizing the surface when the steel is hot. Not everyone has that luxury. I didn't for many years. You can flame harden the steel with a torch, make sure the size is big enough for some dimensional loss when you decarb. D2 is air hardening, so after it's heated, it will cool in still air on a ventilated cooling rack where the air can circulate evenly. Expanded metal works nicely for the rack. This is for smaller sized parts (punch, chisel, lathe bit, etc.) that are easily torch heated. For something with a large cross section (punch press die blocks, etc.) it should be done professionally.

Good info, thanks. I do need a heat treat furnace, but don't have one yet and have limited myself to O-1, W-1, and high carbon steels for that reason.

[Yondering]

I dont see much need for tempering unless the body is too brittle to hand-hold, all the cutting is done with carbide insert.
I was just worried about the body wearing out but maybe even the hardened 4140 will actually last for 1000 bolts and 30 years.
Cutting oil and lower rpm seems to eliminate scuffing and galling marks on the body. Another solution would be 3-insert version so that workpiece only rides on cutting edges. but the body would be lot more tricky to make and I think its more prone to chatter, possibly leading to chipped inserts.

You still want to temper if you harden the steel. At least with O-1 and W-1, you can have stress cracking in the part over time even without using it, if it's not tempered. This depends on the shape of the part of course, but tempering is so easy, there's no reason not to do it. You can even do it in the kitchen oven if that's all you have; just clean off the oil so it doesn't smoke and anger the wife.

[Tim Aldrich]

Ladies and gentleman, I present my version of the Bob Engelhardt mock steady rest. Don't knock my welding. I'm a mechanic, not a welder.

photo 1

photo 2

photo 3

[Tim Aldrich]

Also made some "T" nuts for the mill. One nut, the stud and washer were made for a vise stop. Made a long piece, sawed them apart. Nothing fancy-schmancy about it.



The stop the "T" nuts were made for. I didn't make the stop, it came with my Ames lathe. The maker stamped his initials into it and it is well made. The base has been hardened and the whole thing was a rusty p.o.s. when I got it, but it cleaned up very well.

[rcaffin]

Ladies and gentleman, I present my version of the Bob Engelhardt mock steady rest. Don't knock my welding. I'm a mechanic, not a welder.

I am confused.
It LOOKS as though the steady is mounted on the saddle. If so, what holds the lathe tool???

Cheers
Roger

[Tim Aldrich]

Roger, I got the idea (whole design to be accurate) for this from Bob Engelhardt in a forum thread I had started about a month ago. If you search the forum posts for "steady rest" it should pop up in the first few results. This "mock steady rest" is, indeed, mounted in the tool post. In short, I don't have a proper steady for my lathe and am in the process of making one. However, the only need I've had for a steady thus far is to center drill stock which is too large to pass through my lathe's spindle. I usually then turn the piece between centers. This mock steady idea Bob shared solves my immediate problem of getting an accurate center drilled. I had previously been drilling centers by hand, which worked, but it wasted a lot of material.

[Bob Engelhardt]

Ladies and gentleman, I present my version of the Bob Engelhardt mock steady rest. ...

Tim - thanks for posting that. There's no greater satisfaction for me than having somebody like my idea enough to use it.

[rcaffin]

Hi Tim

Yeah, I did wonder whether it was for drilling.
I don't often need to use a steady, but when I do I align it to the work up against the lathe chuck. I had not thought about what I would do if I did not have a steady.
Understood, thanks.

Cheers
Roger

[Tim Aldrich]

Tim - thanks for posting that. There's no greater satisfaction for me than having somebody like my idea enough to use it.

Thank you for sharing your idea, Bob.

[Jigs]

Hey guys. I'm obviously new to the board but wanted to contribute before I start asking questions


Remember apprenticeships? I may be young, but was put through a vigorous one. I have a father that was/is a tool and die maker. Anyway, I don't recall if there was a reason I made these "V" blocks, I'm sure there was. I was about 16. Heat treated, ground... over 20 years later I still use them on a regular basis. These days it's mostly for inspection, etc.





When I started I thought I had it made. My dads the supervisor. This is going to be great! WRONG! I spent the first couple months with nothing but hand files. Then one day he came to me with drills. I was excited! Wrong again. I spent the next month or so learning how to sharpen drills by hand. They had to cut within .001" or something of their size, I don't remember. I know I was using a scale and loop to get the edges the same size. It was torturous. When it was time to learn the surface grinder, of course my first task was squaring all the used wheels. This place did a lot of grinding. My father showed me mounting a diamond on the table and screwing the table in and out raising it slowly, you get the idea. When I saw the boxes and boxes of wheels I said 'screw this' and made a tool to sharpen the wheels. Days I spent on this tool seemingly getting nothing done, but the owner and my father never questioned what I was doing. They let me go for days, cutting, grinding, heat treating... I made this little guy. The diamond is on a slide that I would just cruise back and forth across the wheel as I raised the table. I went through hundreds of wheels in a couple days. The boss gave me a $100 bonus and my father gave me the approval smile and nod. Remember, there was no NC grinder there.