Sheet metal knockout punches

Mine is 4th Edition, 1953 ;-)

...Jim Thompson

That's true if you have access to both sides, but not so good drilling into the side of a box, where you don't have drill access to the inside. Problem with materials like ali or plastic is that step drills and hole saws deform the material and generate quite a bit of heat. That can work harden the burr, making it a devil to clear. Rotary file bits in the drill can help, but it's still more hassle and leaves a more untidy job than a punch in the end.

Regards,

Chris

"Our"? You certainly don't design with them; too stupid. I lose nothing, AlwaysWrong.

Hmm. I was at the Montgomery store yesterday but didn't buy much (just a magnetic parts dish). I was looking at some of their wrenches but I've bough cheap wrenches before that weren't the marked size. Kinda makes it tough when the wrench is smaller than the bolt. Maybe I'll give them a try.

I have bought their drill bits and use the smaller ones a fair bit. The bigger ones last a long time so I can afford to buy good ones. ;-) I've had a problem with the temper on screwdrivers and alignment of the jaws on pliers. HF isn't alone here but they are pretty bad. I also have their 10" compound sliding miter saw. It's fine for framing but it's not so great for woodworking. I'll likely replace it, perhaps with a Bosch or Dewalt, in a year or so.

Thanks for the links, and thanks for the ones to other HF stuff you've posted in the past. Always appreciated! :-)

Ed

Same here. I got my own copy in the late 70s through a friend in the US. It says that it's the 4th edition, 1952 - reproduced under direction of RCA in April 1953. I had it rebound later and it's still in very good shape. Still comes in useful for some things.

I bought mine in 1954 ;-) I've learned a lot from it, particularly FM detection... thus my low-frequency FSK patent 4,472,816, actually a "S-curve" discriminator ;-) ...Jim Thompson

Grow the f*ck up.

You have no clue, as usual.

You certainly are.

Nothing from nothing leaves nothing. Basic math, nothing boy.

It's available online in PDF format for free.

I had a nice collection of Greenlee punches, but someone stole the whole set. It would be well over $1000 to replace them, these days. The most expensive is the rectangular punch for 4PDT P&B relay sockets.

I was still pre-school then :) Taking into account the state of the art at the time any technical publication is published, and within the limits of my own experience, I think RDH was the best book ever on electronics in that it had just the right blend of theory and practical considerations. It's still highly prized by tube enthusiasts.

That incident must have left an impression with my boss. When the internet arrived in my region almost thirty years later, I managed to find the postal address of one of his former work places. I sent him a letter and in his reply by email, he mentioned the incident and graciously said "You taught me a good lesson that day".

We corresponded for awhile and then tapered off, and I lost his contact info. Sure wish I could find him again - if he's still alive. He must be well over 70 by now.

Thanks for the info. Downloading it now, just in case. I even saw a pdf copy of my first book on electronics: Audels Radioman's Guide.

I just bought an old Crftsman 10" belt drive table saw to replace the one that has an internal motor that quit. Both were built by Emerson over 15 years ago. The internal motor was a custom design, and used an externally mounted Klixon thermal motor starter that is no longer availible. the motor is no longer availible, as well. The belt drive saw is older, but uses a stock 1/2 HP motor and there is very little that can't be repaired or make with a few metalworking tools. I'm going to replace all the bearings as P.M., and the rubber covered levelers will be replaced with some 4" stem casters. It is so heavy that it takes two people to lift it out of my truck, or to move it.

I have several other Crftsman saws that my dad left when he moved north last year. A couple radial arm saws, a miter saw and a couple circular saws. I also have the little 10" table saw from Harbor freight that I use to cut luan plywood. I bought it for $69 a few months ago. Its nothing special, but it works for what I want. I am replacing some paper tray bins with plywood, and i am going to build some 2'*2'*2' boxes that stack

You're welcome. BTW, have you seen their steppless tapered drills?

They would be useful for a few jobs, like needing to slightly open a hole without going a full step. :)

Amphenol quit making the sockets and sold that division to WPI, who was bough by Cooper, who dropped the line. No need for a punch for something you can no longer buy in reasonable quantities. :(

I think I only used the thing once or twice. It was a real pain getting the locking ring on the socket. The standard sockets also give you four handy "ground lugs".

I have the same 4th edition, except reproduced by RCA in 1952.

That book, and the entire six volume RCA Tube Handbook, HB-3, is still useful. The tube handbook contains data sheets back to 1942, but I subscribed to up-dates.

It has the data sheets for the 913, the cathode-ray tube in the first oscilloscope I built in 1942. It had all of one inch screen on a tube that looked like a 6L6, but worked for things like frequency comparison.

It has data for the 954, 959 "acorn" tubes, which I used as rf pre-amps doing radio intelligence intercepts in North Africa while I was in the Army Signal Intelligence Service.

My first engineering job was at Bell Labs, where I "pumped" some of the vacuum tubes the went into TAT-1, the first transatlantic cable. Tubes are still very useful in things like microwave ovens and satellite transmitters. I worked with TWTAs for many years.

(I did teach transistor electronics for UCLA Extension in 1954-1955.)