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- Feb 9, 2017
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So true. And certainly more logical than pipe, now there is something that makes NO sense.
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Tap Size Question?
- Thread starter MacLeod5
- Start date
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- Dec 6, 2012
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- 2,637
Check out: https://www.boltscience.com/pages/screw2.htm
Sellers was in all reality a hero by bringing additional standardization to manufacturing. Arguably this was inevitable as industry attempts to build efficiencies. What we ended up with is fractional and gage sizes. Metric may be the next evolution especially if we move closer to a world economy.
Daryl
MN
Sellers was in all reality a hero by bringing additional standardization to manufacturing. Arguably this was inevitable as industry attempts to build efficiencies. What we ended up with is fractional and gage sizes. Metric may be the next evolution especially if we move closer to a world economy.
Daryl
MN
- Joined
- Mar 26, 2018
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- 8,781
So true about the over - under reamers!!
I would agree too, #8-#10 up to 1/2"
Have numbered and lettered drill bits of good quality. Buy good taps.
Good taps will last years, crap taps will break because they aren't sharp. The cutting forces exceed the taps ability to stay in one piece.
Now that is a scientific statement
I would agree too, #8-#10 up to 1/2"
Have numbered and lettered drill bits of good quality. Buy good taps.
Good taps will last years, crap taps will break because they aren't sharp. The cutting forces exceed the taps ability to stay in one piece.
Now that is a scientific statement
- Joined
- Mar 26, 2018
- Messages
- 8,781
I'm in big trouble.
- Joined
- Apr 14, 2014
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- 3,585
First to address the numbering system for smaller drills and taps. They roughly follow the Stubs Steel Wire Gauge measurements developed in Brittan during the late 19th century. This was one of the earliest attempts to standardize drill and tap sizes. Over the years more than a dozen attempts were made to standardize wire gauges, and there are still over half a dozen systems still in use. Keep in mind these attempts at "standardization" were made in a time when industry was attempting to switch from individual craftsman to a system of mass production with interchangeable parts. There was no single authority of consortium to dictate what the standards should be. Each industry made it's own set of standards.
I see it much like early attempts at bar coding. The first commercial attempts were made in the early 1970's. Since then more than 30 systems have been developed in different countries for different industries.
I must be the odd man out once again as far as in stock tap & drill sizes are concerned. I grew up and worked with imperial sizes so to me they're common place. Numbers, letters, and fractions were the standard throughout industry in the US. Into the 1980's US industries started moving to the metric system to capture more of the world market. By the early 2000's almost any product from automobiles to soft drinks were either made with or sold by metric measurements. It's just one more attempt to standardize. This time rather than within a country it's world wide.
Even the metric system isn't as cut and dried as some might think. There are currently 7 base systems, and another 22 sub systems with specific names.
I see it much like early attempts at bar coding. The first commercial attempts were made in the early 1970's. Since then more than 30 systems have been developed in different countries for different industries.
I must be the odd man out once again as far as in stock tap & drill sizes are concerned. I grew up and worked with imperial sizes so to me they're common place. Numbers, letters, and fractions were the standard throughout industry in the US. Into the 1980's US industries started moving to the metric system to capture more of the world market. By the early 2000's almost any product from automobiles to soft drinks were either made with or sold by metric measurements. It's just one more attempt to standardize. This time rather than within a country it's world wide.
Even the metric system isn't as cut and dried as some might think. There are currently 7 base systems, and another 22 sub systems with specific names.
- Joined
- Feb 17, 2013
- Messages
- 4,409
First off, welcome to the forum!
IIRC, at least one sheet metal gauge system was based on how many times the sheet was run through the press rollers ... thus, the higher the number, the thinner the sheet. Wire gauges (higher number = thinner diameter) probably originated the same way ... keep drawing the wire through smaller and smaller holes.
Pipe: "Standard" pipe sizes were originally based on the inside diameter. Way back when, materials weren't as strong, so the walls of the pipe had to be a lot thicker than they are now. As stronger materials came into use, the wall thickness could be reduced. But in order for the new pipe to mate with existing threaded fittings, it was the inside diameter that was adjusted, rather than the outside. So nowadays, nothing about a 1/2" pipe or fitting even comes close to measuring out to 1/2". The Wikipedia article on BSP threads covers this history, more so than the NPT article.
en.wikipedia.org
... and if you think the UNC/UNF/UNS system is confusing, just think about our friends across the sea ... they have to bring BA and Whitworth to the party, along with US and Metric standards!
en.wikipedia.org
en.wikipedia.org
Lots of fascinating history is at work here.
IIRC, at least one sheet metal gauge system was based on how many times the sheet was run through the press rollers ... thus, the higher the number, the thinner the sheet. Wire gauges (higher number = thinner diameter) probably originated the same way ... keep drawing the wire through smaller and smaller holes.
Pipe: "Standard" pipe sizes were originally based on the inside diameter. Way back when, materials weren't as strong, so the walls of the pipe had to be a lot thicker than they are now. As stronger materials came into use, the wall thickness could be reduced. But in order for the new pipe to mate with existing threaded fittings, it was the inside diameter that was adjusted, rather than the outside. So nowadays, nothing about a 1/2" pipe or fitting even comes close to measuring out to 1/2". The Wikipedia article on BSP threads covers this history, more so than the NPT article.
British Standard Pipe - Wikipedia
... and if you think the UNC/UNF/UNS system is confusing, just think about our friends across the sea ... they have to bring BA and Whitworth to the party, along with US and Metric standards!
British Association screw threads - Wikipedia
British Standard Whitworth - Wikipedia
Wow - team, what a response. Really great information here, and I sincerely appreciate the depth of knowledge and the humor! Let me ask this - should I not be afraid of single point threading? As soon as I saw a die holder project I was thinking to myself "that look a lot less dangerous, plus I don't have to change all the gears after trying to interpret the incoherent table printed on my small import 7x14 lathe." I have seen the upside-down threading that goes toward the tailstock and that looks interesting, too.
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- Sep 1, 2020
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The inch is metric.
- Joined
- Sep 1, 2020
- Messages
- 793
Please post a video of single point threading of #2-56
I like dies, die holders and taps for that stuff. I'm no miniature model builder either. They made watches by hand. I emphasize "they ".
- Joined
- Feb 2, 2020
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- 146
For SAE, I'm pretty well covered. #3 to at least 1". The #3 came in handy when I had to cut down glass scales for my DRO. The original screws were metric and I didn't have anything that small in metric.
I have a decent selection of metric, 4mm through 12. I need to buy a 14x1.5 tap though. I have a great selection of SAE because I have bought a couple of toolboxes loaded with taps. All of them are USA made and some that have never been used.
I have a decent selection of metric, 4mm through 12. I need to buy a 14x1.5 tap though. I have a great selection of SAE because I have bought a couple of toolboxes loaded with taps. All of them are USA made and some that have never been used.
