Tap and Die. What size handle do I need for a 1¼" BSP tap.

Gromett

Gromett

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Ordered a 1¼" BSP tap earlier today. Just realised my handle won't fit that so need to order one.
Unfortunately I don't know how big the shank is on the tap. Can any one advise please?

All the handles on Amazon appear to be specified in M sizes. M4-M10 up to M9-M27
27mm is over 1" so possibly big enough but I am not sure and I don't really want to waste £24 on a handle I won't use.

Any advice gratefully received. The other option is driving to toolstation/screwfix etc.
 
In case any one is curious. Chunky boy.

1713830640060.png

www.ebay.co.uk

1 1/4 x 11 bsp hss thread tap | eBay

<p dir="ltr" style="margin-top:0; margin-bottom:0;">1 1/4 x 11 bspf hss thread tap.</p> <p dir="ltr" style="margin-top:0; margin-bottom:0;">Decent quality new plug tap</p> <p dir="ltr" style="margin-top:0; margin-bottom:0;">parallel thread</p> <p dir="ltr" style="margin-top:0...
www.ebay.co.uk

Also ordered this set. Only currently need the ½" but may as well get the full set as it works out cheaper in the long run than buying them all separate.
 
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Blimey that is a big boy, ive only got small taps & dies so cant help sorry.
 
You will be able to find a socket that fits and then just use a sliding bar if you have one or even just a normal socket wrench at a push, this is assuming you are only tapping 1 or 2 holes, if more OK buy a proper handle but not sure on size.
 
As above sliding t bar

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If you are cutting a new thread I hope you have the tapered tap as well.

You might get away with two spanners to use it, or one spanner and an adjustable.
 
If that is for cutting a new thread rather than clearing-out an existing one go as big as you can. It might be difficult to keep it straight without a tapered tap to start with. Bonne chance - as they might say around here! Incidentally don't you sleep?
 
A quick scale up from the picture and knowing that the id of the tap should be 1.650", I'd say the shank is 1.250" or inch and a quarter in old money or 31.8 mm so that's M22 territory.
 
funflair said:
this is assuming you are only tapping 1 or 2 holes, if more OK buy a proper handle but not sure on size.
Click to expand...
I will be tapping quite a few holes and it will be ongoing.
DBK said:
If you are cutting a new thread I hope you have the tapered tap as well.
Click to expand...
It is for plastic not metal. I will eventually have a jig to hold the tap vertical and allow gentle pressure. I was thinking of using a drill press when I get one eventually.
But currently I think I can get it going into the material if I am careful. the material is HDPE and is 20mm thick. So not a huge job.
varaizian said:
If that is for cutting a new thread rather than clearing-out an existing one go as big as you can. It might be difficult to keep it straight without a tapered tap to start with. Bonne chance - as they might say around here! Incidentally don't you sleep?
Click to expand...
I do sleep, but the contract I am on currently is for a Canadian company. Their 8am is our 4pm. So I do work late, then I need a bit of time to wind down.

jockaneezer said:
A quick scale up from the picture and knowing that the id of the tap should be 1.650", I'd say the shank is 1.250" or inch and a quarter in old money or 31.8 mm so that's M22 territory.
Click to expand...
Hmmm. I think I will wait till it arrives before going further. I see where you are coming from though so I am now not worried about being about to get one big enough. (y)
 
Thanks everyone for the suggestions (y) :D
 
Just looked at that set again and realised it was a taper set not a parallel set. Cancelled. They all seem to be taper threads on amazon grrr.
 
Oh Jeez. Seems the sellers don't understand or maybe I don't. I have never dealt with BSP before
But apparently it comes in two main flavours parallel and tapered.

Taps for cutting the holes also use the tapered terminology as in tapered, 2nd cut or plug.

So I am actually looking for a tapered 1/2" parallel BSP (BSPP) tap.

Seems a lot of sellers don't understand to put in parallel or tapered as the thread type as well as which type of tap.

The only supplier I have found so far that is reasonably priced that appears to understand this is a steam model train company.

1713873209497.png

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So I am actually looking for a tapered 1/2" parallel BSP (BSPP) tap.

You can't have both in one.....like asking for a dry wet towel.
You first pic is parallel, the set in the link is taper.
 
pappajohn said:
So I am actually looking for a tapered 1/2" parallel BSP (BSPP) tap.

You can't have both in one.....like asking for a dry wet towel.
You first pic is parallel, the set in the link is taper.
Click to expand...

You perhaps misunderstood me or I didn't explain myself well.

There are 2 types of BSP thread. Tapered and parallel.

There are 3 types of tap tapered, 2nd and plug.

So you can have a tapered tap for a tapered or parallel thread.

British Standard Pipe - Wikipedia

en.wikipedia.org en.wikipedia.org

1713875745431.png


I am after the BSPP not the BSPT taps. That multipack I ordered was BSPT threaded.
 
BSPP taps will normally come with a 1st cut (tapered) and plug for the final parallel thread. Trying to start a plug tap without the 1st cut is quite difficult.
BSPT taps can come in sets still with the 1st cut providing a starting thread before finishing with the 2nd tap although not always as in some instances you can get away with just the one tap.
Parallel threads are normally used with a sealing washer (Copper, bonded or Dowty) underneath the head of the fastener.
Tapered threads are generally used where the mating thread provides the seal, possibly in conjunction with thread tape.
 
Gromett said:
You perhaps misunderstood me or I didn't explain myself well.

There are 2 types of BSP thread. Tapered and parallel.

There are 3 types of tap tapered, 2nd and plug.

So you can have a tapered tap for a tapered or parallel thread.

British Standard Pipe - Wikipedia

en.wikipedia.org en.wikipedia.org

View attachment 889020

I am after the BSPP not the BSPT taps. That multipack I ordered was BSPT threaded.
Click to expand...
Agreed but it depends how deep you can cut a taper thread to produce a parallel thread.
If you want 1" of parallel the tail end of the tapered tap would need to be 1" inside the hole
 
pappajohn said:
Agreed but it depends how deep you can cut a taper thread to produce a parallel thread.
If you want 1" of parallel the tail end of the tapered tap would need to be 1" inside the hole
Click to expand...
You are confusing me. I honestly don't understand what you are saying now sorry :(

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TheTwoOfUs said:
BSPP taps will normally come with a 1st cut (tapered) and plug for the final parallel thread. Trying to start a plug tap without the 1st cut is quite difficult.
BSPT taps can come in sets still with the 1st cut providing a starting thread before finishing with the 2nd tap although not always as in some instances you can get away with just the one tap.
Parallel threads are normally used with a sealing washer (Copper, bonded or Dowty) underneath the head of the fastener.
Tapered threads are generally used where the mating thread provides the seal, possibly in conjunction with thread tape.
Click to expand...
So there are definately 2 types of BSP thread and I need to ensure I get the right tap. That was what I was saying (y) :)
 
Yeah, it can be confusing at times, especially when vendors use the"taper" terminology instead of 1st, second and plug/bottoming tap ?
BSPT is usually used on steel pipework and it relies on the tapered male pipe "interfering" with the corresponding tapered female fitting to provide a "mechanical" seal, although you generally help it along with some ptfe tape or "pipe dope"
BSPP is generally used on fittings that screw into manifolds/valves etc and require a "mechanical seal" such as a copper washer or an O ring to provide their integrity and are often used in high pressure hydraulic systems.
Depending on your needs and whether you actually need a competent gas/liquid seal, you may be able to get away with a bit of "mix and matching" ?
A BSPT tap threaded all the way through your job and out the other side may leave a BSPP thread (best to try a dry run first though !) (As pappajohn was alluding to ?)
Then you can throw American NPT threads into the mix, which are similar to BSP, but have a 60° thread angle instead of the 55° Whitworth form of BSP.
 
jockaneezer said:
Yeah, it can be confusing at times, especially when vendors use the"taper" terminology instead of 1st, second and plug/bottoming tap ?
BSPT is usually used on steel pipework and it relies on the tapered male pipe "interfering" with the corresponding tapered female fitting to provide a "mechanical" seal, although you generally help it along with some ptfe tape or "pipe dope"
BSPP is generally used on fittings that screw into manifolds/valves etc and require a "mechanical seal" such as a copper washer or an O ring to provide their integrity and are often used in high pressure hydraulic systems.
Depending on your needs and whether you actually need a competent gas/liquid seal, you may be able to get away with a bit of "mix and matching" ?
A BSPT tap threaded all the way through your job and out the other side may leave a BSPP thread (best to try a dry run first though !) (As pappajohn was alluding to ?)
Then you can throw American NPT threads into the mix, which are similar to BSP, but have a 60° thread angle instead of the 55° Whitworth form of BSP.
Click to expand...
It is for plastic tanks. I am making (CNC) inserts for a plastic tank and want to fit ½" and 1¼" BSP plastic and brass fittings.

Such as this
Or this
 
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You will definitely need a parallel tap and you will also need to ensure that the face of the tank is flat and free from defects, scratches etc so that the seal will do its job.
PS Also the thread will have to be perpendicular to the face of the tank.

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Last edited:
TheTwoOfUs said:
You will definitely need a parallel tap and you will also need to ensure that the face of the tank is flat and free from defects, scratches etc so that the seal will do its job.
PS Also the thread will have to be perpendicular to the face of the tank.
Click to expand...
The insert is being CNC'd so will be extremely accurate down to .2mm tolerance. The material is mirror smooth.
And I know I need the parallel tap but thanks for confirming. :) It was finding a supplier who stated the tap was parallel as most don't even specify one way or another.

I will be posting pictures and perhaps video once I get going. Probably end of the month before the inserts are done.
 
Cut the the thread with a BSPP taper tap first. If you only use the tap you showed you risk stripping the thread when the tap quickly becomes clogged with swarf. A tapered tap takes off a bit at a time. You may still have to reverse the tap to clear it, which will be tricky to do avoiding cross threading when you come to restart cutting.

Cutting a thread that big in 20mm thick material isn't a trivial task. You might also want to look at a lubricant, they do exist for cutting threads in plastic.
 
DBK said:
Cut the the thread with a BSPP taper tap first. If you only use the tap you showed you risk stripping the thread when the tap quickly becomes clogged with swarf. A tapered tap takes off a bit at a time. You may still have to reverse the tap to clear it, which will be tricky to do avoiding cross threading when you come to restart cutting.

Cutting a thread that big in 20mm thick material isn't a trivial task. You might also want to look at a lubricant, they do exist for cutting threads in plastic.
Click to expand...
Just use an adjustable spanner,i,ve been a pipefitter for over 50yrs and on the rare occasion where a tap is reqd that's all i've used, just make sure you keep it square to the hole and use plenty of oil
 
The big boy arrived today and jeez it is bigger than it looks in the picture.


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