Air manifold with 1/8" British Standard Parallel Pipe thread

[Martin W]

Hello
I have a Holzher edge banding machine. Someone stripped one of the aluminum ports on the airline manifold. It is a 1/8" BSPP. Still trying to find out from Holzer if this part is available. In the meantime I have ordered a tap from McMaster Carr. I am going to make a new block that attaches to the original manifold.

Is there a reason this part is made from aluminum? It is 1-1/2" x 1-1/2" x 1/2". It has 3 - 6mm ports, two are threaded and one is squished into an O ring. It is bolted to the main manifold with 2 bolts. This little block also has 3 banjo fittings with 6 airlines from the 3 six mm ports.

Should I stick with aluminum or make it from steel? Would the 29/64" tap drill be the same for both materials? I am not sure why these are aluminum in the first place? the threads are only about 10mm long, not much to grab to start with.
Thanks
Cheers
Martin

 

[ErichKeane]

Not familiar with the machine, so these are some generalized answers:

Aluminum is cheap and easy to machine, I'm guessing that is why. Additionally, if it is an air manifold that deals with compressed air, water will often get forced out of the air, like in an air-compressor tank. Aluminum doesn't rust the way plain steel would.

I'd probably use aluminum to remake it (depending on how long the part made it!), since you should just be assembling this once or twice, right? There isn't a huge amount of assembly/disassembly I'd imagine, so it shouldn't matter once assembled. If you're that worried about it, you might consider stainless.

Tap drill is the same, but the harder the material, the harder the tap is to turn of course (use tapping fluid!). That said, 29/64" sounds WAY too large. Isn't 1/8" BSPP supposed to be an 11/32" drill?

10mm is pretty long, generally threads are fine as long as there is a couple of threads engaged. 10mm on 1/8" BSP is 11 threads of engagement.

 

[FOMOGO]

Might be a lot simpler to just weld up the one port, and re-drill and tap if you have that capability or have someone close by. Mike

 

[John O]

Could a bushing be made somewhat of a heli-coil?

 

[NC Rick]

Hello
I have a Holzher edge banding machine. Someone stripped one of the aluminum ports on the airline manifold. It is a 1/8" BSPP. Still trying to find out from Holzer if this part is available. In the meantime I have ordered a tap from McMaster Carr. I am going to make a new block that attaches to the original manifold.

Is there a reason this part is made from aluminum? It is 1-1/2" x 1-1/2" x 1/2". It has 3 - 6mm ports, two are threaded and one is squished into an O ring. It is bolted to the main manifold with 2 bolts. This little block also has 3 banjo fittings with 6 airlines from the 3 six mm ports.

Should I stick with aluminum or make it from steel? Would the 29/64" tap drill be the same for both materials? I am not sure why these are aluminum in the first place? the threads are only about 10mm long, not much to grab to start with.
Thanks
Cheers
Martin

Since the BSPP uses a crush washer or rubber sealing element, you won’t have the problem of material strength like you do with tapered threads. I’d roll with aluminum if I couldn’t do a weld repair.

 

[ErichKeane]

Could a bushing be made somewhat of a heli-coil?

Looks like a new helicoil set can be had for about $80! https://britishfasteners.com/uni-thread-repair-kit-bsp-1-8-28-31020.html

 

[markba633csi]

JB weld, JB weld, JB weld- say the magic words and click your calipers together 3 times

 

[Martin W]

Not familiar with the machine, so these are some generalized answers:

Aluminum is cheap and easy to machine, I'm guessing that is why. Additionally, if it is an air manifold that deals with compressed air, water will often get forced out of the air, like in an air-compressor tank. Aluminum doesn't rust the way plain steel would.

I'd probably use aluminum to remake it (depending on how long the part made it!), since you should just be assembling this once or twice, right? There isn't a huge amount of assembly/disassembly I'd imagine, so it shouldn't matter once assembled. If you're that worried about it, you might consider stainless.

Tap drill is the same, but the harder the material, the harder the tap is to turn of course (use tapping fluid!). That said, 29/64" sounds WAY too large. Isn't 1/8" BSPP supposed to be an 11/32" drill?

10mm is pretty long, generally threads are fine as long as there is a couple of threads engaged. 10mm on 1/8" BSP is 11 threads of engagement.

Thanks for replying Eric
i didn’t have my glasses on. 29/64” is for 1/4” BSPP. Tap drill size is letter drill Q .
I agree on the aluminum.

 

[Martin W]

Might be a lot simpler to just weld up the one port, and re-drill and tap if you have that capability or have someone close by. Mike

Good idea! Never even occurred to me to that
Thanks
Cheers
Martin

 

[Martin W]

Since the BSPP uses a crush washer or rubber sealing element, you won’t have the problem of material strength like you do with tapered threads. I’d roll with aluminum if I couldn’t do a weld repair.

Also a good idea, Thanks