Dial Indicator Attachment

[rossbotics]

I've made lathe form tools from O-1 drill rod. As well shafts for needle bearings to run on, and sand blast nozzles (which I don't temper). I did have one mishap, I made a replacement bandsaw blade tension bolt for my 4x6 import saw. The original bolt stripped out. I thought, "I don't need to temper this", well it didn't take to long for the shaft just above the threads to fail. Snapped right off. It did teach me that tempering was a required process if you don't want it to shatter like glass.

So what is your method of cleaning up the burnt oil residue? I've found removal to be a PITA to get a clean surface.

Also here is a color chart for steel

[metric_taper]

After it's cooled down I just wipe it off and go to the grinder where I have a wire wheel and get the crud off, I then take some 220 grit by hand and clean it up, heat it back up to a straw color and quench her once more, I have two surface plates of different sizes and only use them for inspection Etc. go down to your local granite shop and get you one of there drops, they gave me mine, I got two pieces of that stuff there about 14" X 16"just for laying down full sheets of wet dry 600-800-1000 and do polishing or whatever on, this stuff is incredibly flat, you can use this plate like a lap with a piece of 600 wet dry, or you can grind it all over like I did, this is the best way, If you find your slot closed a little bit from the heat treating you can put it back in the mill with the same parallel setup and with a 1/4" carbide end mill and clean the slot up.

Hope this helps

Doug, thanks for your reply:
A stationary wire wheel I do not have. I've used them at friends homes, they just are too easy to have large chunks of skin removed (and my skin is getting thinner every day). Scary enough to use a buffing wheel, which is what I tried to use in the past to remove the oxide coating from heat treat. It was ineffective as I could not cut the oxide off without hours of effort.
Just a few weeks ago, a guy advertised polish black granite slabs, that at one time were the exterior facade of a bank gone long ago. I calculated the weight from the description, 296lbs. But for $20, how could I go wrong. And that was my intent was for a lapping plate. Way too big, so the next project is to cut it down with a diamond blade in a circular saw. It would make a good surface plate, as I assume it was polished flat via a lapping process. But at 4" thick, probably is concave if held near its edges (at it's current size). I also purchased sheets of wet dry sand paper (eBay), from 280 grit to 5000. I played a little on it with a piece of brass.

[metric_taper]

A stationary wire wheel I do not have.

Sometimes I don't think of tools I have and they get lost in their piles. I have a 4 inch angle grinder. And I have a wire cup wheel for it. That works pretty good at removing munge. I also can control it to my safety desire.

[NortonDommi]

Hi metric_taper,
Using a wire wheel on a grinder or polisher is safe, just let the wheel do the work and don't use force. About the only machinery that it is safe to use wearing gloves is a grinder or polisher. I spent years of school holidays working in my dads polishing business and only on special small work would we use bare hands.
I can recommend riggers gloves as they are light, fit well and protect the hands from an accidential touch.

[Dr Stan]

About the only machinery that it is safe to use wearing gloves is a grinder or polisher. I spent years of school holidays working in my dads polishing business and only on special small work would we use bare hands.

That is a negative. I worked in the tool maker/job shop machinist trade for 10 years then taught it and other classes for an additional 40 years. NO GLOVES were allowed around rotating machinery, no exceptions.

I had a student at Mississippi State leave on some welding gloves when he went to clean up the edge of a sq piece of 1/8" thick steel for a welding exercise. He lost his nail on his RH thumb when it was pulled into the wheel. One of only three shop/lab injuries I had in my time teaching. The other two were due to equipment failures. Yes I know welding gloves are loose, but a no glove policy is best. This was also the policy when I went through the Navy's Machinery Repairman school and onboard ship.

BTW, for those who think using pliers or vice grips to hold a small piece against a grinding wheel, think again. That's virtually guaranteed to end up with the piece flying across the shop. If its too small to hold by hand, then use a small vice and a pencil grinder.

[MeJasonT]

Interesting advice both on gloves and holding work piece in molegrips

[Frank S]

One more hand safety tip I feel needs mentioned.
I've seen countless machinists do this, and recently even watched a few of those instruct-able vids published by folks who have published dozens of how to videos.
Where the machinist places a small swatch of Emory cloth or scotchbrite on the tip of his finger then inserts it into the bore of a spinning cylinder to polish the bore
I was even guilty of doing this twice first and last at the same time early on while teaching myself how to use a lathe. The bore caught the swatch and twisted my finger around fortunately it didn't rip my finger off or even break or dislocate a bone all it did was rip skin and meat loose from the bone leaving my nail on the underside of my finger. I was able to twist the skin and nail back in place then wrapped it with gauze and made a splint then taped it up real good.
my finger had that stinging needle feeling for quite a while the nail later came off but grew back and everything healed up just fine
That happened close to 50 years ago and to this day when the inside of a cylinder needs dressing I use a split wooden dowel rod with a swatch placed in the slot my fingers or hands do not go inside of a spinning cylinder.

[metric_taper]

Interesting advice both on gloves and holding work piece in molegrips

Mole grips, is that the local brand name, or some other colloquial?

Never mind:

I googled it, wikipedia tells the story. And it is a Newport South Wales manufacture M. K. Mole and Son. Mole wrench.

[Dr Stan]

Excellent advise as one can repeatedly do "something" for years & get by with it, but it only takes one time to acquire an injury.

[tonyfoale]

Where the machinist places a small swatch of Emory cloth or scotchbrite on the tip of his finger then inserts it into the bore of a spinning cylinder to polish the bore
................
That happened close to 50 years ago and to this day when the inside of a cylinder needs dressing I use a split wooden dowel rod with a swatch placed in the slot my fingers or hands do not go inside of a spinning cylinder.

Around the same time period, a young apprentice, the future son-in-law of the boss, was screw cutting a long internal 7/8" thread. Just big enough for a finger. He used his finger to try to extract some swarf and, you guessed it, the thread just screwed up his digit and pulled it straight off. As I gave first aid, another began gently turning the part down to extract the remains of the finger. I don´t recall if it was successfully attached but the memory of it remains with me.
In general I am not a model for a safty poster, I might not stick my finger into an internal thread but Frank I still do what you did and other things that I know to be unsafe. Laziness is usually the reason and I still do the same things even after I´ve been bitten, I have a few scars but nothing too serious. Stupid, yes, no argument there.