The Home Machinist!

A modern UN tap and die will, if used with materials that are the appropriate major and minor, leave a compliant crest and root.

As you come to the end of the weld you should back off on the amps and add filler. Then (and this is important) you should hold the torch over the weld till you see if solidify so that the shielding gas keeps it form oxidizing. If the gas shuts off before the weld stops glowing you should extend the...

If your tungsten is turning black there is something odd going on. Are you using the tungsten (without putting a fresh point on it) after it becomes contaminated?

Dan

What conceivable merit does the imperial system have, apart from making people really good at fractions? It occurred to me last week that a system built on the length of a body part is easy to relate to. I know instinctively the approximate sizes of a foot, an inch and even a yard. And then there i...

Typically, you have two choices. 1) make a mold of the cavity using something like cerrosafe (low melt temperature meta) and use that to determine the major and minor as well as to verify the thread form. 2) Assume that the crest of the internal thread is the minor diameter and reverse engineer the ...

. For the home shop guy who isn't concerned with such things, yeah, it doesn't matter, but a guy who's trying to satisfy stringent QC is going to get one hell of a rude wakeup call. Plain and simple---one does not work to major and minor diameters when creating threads. Observe proper tool geometry...

The UN thread specifies a flat root to minimize cracking from stress risers. The standard says the edges of the flats may have a radius but the radius must start at the major diameter. To do it right, each thread will have it's own tool with the tip matching the thread's profile. To make life easier...

The Unified thread is defined by the geometric relationships of it's features. Because humans are involved, there are multiple tolerance classes, and they are also defined. In a commercial endeavor you have to meet tolerances. In a home shop you usually don't. Since the OP has already violated the U...

I've been successfully cutting threads the way Heavyg603 did for years. It is no problem to cut both Internal and external threads that way and have them fit well without resorting to making a "test male thread" to use as a go/nogo gage. The trick is that the thread form that he's created ...

Using a 7x12 Seig S2 mini lathe. ( that's a 3 1/2 inch lathe in the UK) I recall it's about 350watts. I use coated carbide triangular inserts with positive rake and have no trouble with .030 inch DOC in steel and aluminum. I've pushed it to .050 at times.

Dan

And can anyone who has a 6x26 mill tell me what the frame size is on their motor . One of the first things I'd like to do is pitch the single phase motor . Unfortunately the only one who can answer this properly is someone who has the exact same model. Mine looks the same but since it is 40 years o...

The clue may be in the phrase "The speed of preparation allows me to devote a much bigger percentage of my time welding instead of grinding and cutting. " Aluminum develops a high resistance oxide very quickly. Standard prep is to clean it, then brush with a dedicated stainless brush, then...