Best Place to get a G1/4 BSPP tap?

[guest]

I have just finished a major search in all things BSP related. Here's the short of it.



BSP British Standard Pipe

This comes in taper and parallel. The jargon varies on how to describe the tap. Most common is the BSPT or BSPP but I have seen BSP be parallel.

Then we get into all the variations

G, how I’ve come to hate this letter. This means Gas, which means… about anything. Most common is a reference to a BSW ( I haven’t introduced this one yet) or a parallel thread.

So now BSW similar to the rest but the W is for whitworth. This seems to have the most association with ‘G’, though I have seen it referenced as something other than the BS family

This reference is pretty good and seems to be accurate.

http://en.wikipedia.org/wiki/British...rd_pipe_thread

So what you have is a BSPP(‘L’ is sometimes here) whitworth 55 degree thread. There is also a full form and modified form. The full form is from Europe and couldn’t be made in the US and so the US made a modified. Now everyone can make it and so… good luck with that but it shouldn’t make a lot of difference. Has to do with a radius on the minor axis.

As for getting one… prepare thyself…..

This link has some for a very good price. I myself need a 1/8 G, but these are like 220 V 50 Hz. Uncommon here and so expensive.

http://www.blujay.com/item/NEW-4-PCS...060000-1738603

McMaster Carr has some if you use BSPP in the search. It doesn’t say if it is whitworth or full or modified. There may be other places as well. If you search for BSPP and look for a ¼ you should be ok but remember that the jargon can confuse what you’re getting. It will likely take a call to confirm.

[Martinm210]

FYI
I ordered the BSPP tap from Master Carr and it turned out to be the bottomless variety. I also picked up an 11.8mm drill bit to go with it.

They are both very nice and worth the money, but you probably would want a tapered cut tap if you're hand tapping.

I like the bottomless because I'm tapping in my mill, but it would probably be a PITA to keep a nice perpenticular tap by hand.

The 11.8mm drill bit also works wonders by removing just the right amount of material. I'm literally able to hand tap in plastics by hand turning my chuck without any wrench and threads are perfect every time. I was not able to do that with the NPT-18 tap, and threads were never perfect either.

Anyhow, I'm glad it is bottomless, but something to watch for if you're ordering from Mcmaster-carr...

[Waterlogged]

I have just finished a major search in all things BSP related. Here's the short of it.



BSP British Standard Pipe

This comes in taper and parallel. The jargon varies on how to describe the tap. Most common is the BSPT or BSPP but I have seen BSP be parallel.

Then we get into all the variations

G, how I’ve come to hate this letter. This means Gas, which means… about anything. Most common is a reference to a BSW ( I haven’t introduced this one yet) or a parallel thread.

So now BSW similar to the rest but the W is for whitworth. This seems to have the most association with ‘G’, though I have seen it referenced as something other than the BS family

This reference is pretty good and seems to be accurate.

http://en.wikipedia.org/wiki/British...rd_pipe_thread

So what you have is a BSPP(‘L’ is sometimes here) whitworth 55 degree thread. There is also a full form and modified form. The full form is from Europe and couldn’t be made in the US and so the US made a modified. Now everyone can make it and so… good luck with that but it shouldn’t make a lot of difference. Has to do with a radius on the minor axis.

As for getting one… prepare thyself…..

This link has some for a very good price. I myself need a 1/8 G, but these are like 220 V 50 Hz. Uncommon here and so expensive.

http://www.blujay.com/item/NEW-4-PCS...060000-1738603

McMaster Carr has some if you use BSPP in the search. It doesn’t say if it is whitworth or full or modified. There may be other places as well. If you search for BSPP and look for a ¼ you should be ok but remember that the jargon can confuse what you’re getting. It will likely take a call to confirm.

I (or C'DaleRider or any other machinist) could have saved you a lot of work if you had asked. BSP is also usually followed by a letter designation to specify exactly which BSP should be made. You forgot another common letter as well. "R" designates a tapered (otherwise known as a BSPT) thread. As stated in the Wiki, all BSP threads are based on the Whitworth thread.

Here's some more on BSP threads straight from the Machinery's Handbook 26th Edition which is more or less the Bible for anyone in design or manufacturing.



Also, BSPP (G) seals with O-Rings (teflon tape or pipe dope is nearly useless on these), BSPT (R) seals with Teflon tape (or pipe dope). It's best not to mix the two types of threads as you'll only have only a few threads grabbing which ever way you mix, thereby increasing your risk of a leak.

FYI
I ordered the BSPP tap from Master Carr and it turned out to be the bottomless variety. I also picked up an 11.8mm drill bit to go with it.

They are both very nice and worth the money, but you probably would want a tapered cut tap if you're hand tapping.

I like the bottomless because I'm tapping in my mill, but it would probably be a PITA to keep a nice perpenticular tap by hand.

The 11.8mm drill bit also works wonders by removing just the right amount of material. I'm literally able to hand tap in plastics by hand turning my chuck without any wrench and threads are perfect every time. I was not able to do that with the NPT-18 tap, and threads were never perfect either.

Anyhow, I'm glad it is bottomless, but something to watch for if you're ordering from Mcmaster-carr...

Bottomless?

Sorry, couldn't help myself.

It seems it's been a very long time since you were on the floor of a shop. The styles of taps available are Bottoming, Plug, and Tapered. With a BSPP or NPSM, the only style tap available is a bottoming as there can't be any taper otherwise it's not a BSPP or NPSM.

[Martinm210]

Bottomless?

Sorry, couldn't help myself.

It seems it's been a very long time since you were on the floor of a shop. The styles of taps available are Bottoming, Plug, and Tapered. With a BSPP or NPSM, the only style tap available is a bottoming as there can't be any taper otherwise it's not a BSPP or NPSM.

Ok, it's a tap for threading holes that are "Bottomless" you know what I meant...lol...

Just because I worked in a shop didn't mean I knew the proper terminology. I did know what each was used for though.

For tapered I mean the taps that are cut tapered, not the actul threading tapered. All of my regular taps are cut at a taper for a good 1/3 the length of the tap except this one which tapers to full threads in the first 3 or so threads.

No problem when tapping on my mill or the drill press, but that would be less than fun tapping by hand without something to hold it plumb.

[Waterlogged]

Ok, it's a tap for threading holes that are "Bottomless" you know what I meant...lol...

Just because I worked in a shop didn't mean I knew the proper terminology. I did know what each was used for though.

For tapered I mean the taps that are cut tapered, not the actul threading tapered. All of my regular taps are cut at a taper for a good 1/3 the length of the tap except this one which tapers to full threads in the first 3 or so threads.

No problem when tapping on my mill or the drill press, but that would be less than fun tapping by hand without something to hold it plumb.

I should expand on that so ppl know what I talking about. Like I stated before, taps come in 3 basic styles (it then can get complicated from there but, that's another story). They are Bottoming, Plug and Taper. These names actually refer to the end of the tap that does the cutting and are for screw threads only. Pipe taps, have only one type per style of thread. That means if the pipe thread is a NPT or BSPT, the tap will be ground with the proper taper with the proper "finished" threads being somewhere near the middle of the taper. If the thread is NPSM or BSPP, it will have 2-3 thread chamfered starter threads and the rest will be ground straight (parallel).

Here's a bit more info on screw thread taps

Chamfer Length: Three types of hand taps, used both for hand and machine tapping, are
available, and they are distinguished from each other by the length of chamfer. Taper taps
have a chamfer angle that reduces the height about 8–10 teeth; plug taps have a chamfer
angle with 3–5 threads reduced in height; and bottoming taps have a chamfer angle with 11⁄2
threads reduced in height. Since the teeth that are reduced in height do practically all the
cutting, the chip load or chip thickness per tooth will be least for a taper tap, greater for a
plug tap, and greatest for a bottoming tap.
For most through hole tapping applications it is necessary to use only a plug type tap,
which is also most suitable for blind holes where the tap drill hole is deeper than the
required thread. If the tap must bottom in a blind hole, the hole is usually threaded first with
a plug tap and then finished with a bottoming tap to catch the last threads in the bottom of
the hole. Taper taps are used on materials where the chip load per tooth must be kept to a
minimum. However, taper taps should not be used on materials that have a strong tendency
to work harden, such as the austenitic stainless steels.