BSP or BSPT

[mtrehy]

Hi,

I want to tap an oil gallery and insert a threaded bung in it rather than a push fit bung. Just wondered what peoples opinions are, should I just tap 1/4 bsp and screw in a 1/4 bsp blanking plug until it goes tight, or should I tap 1/4 bspt and put a taper bung in..? Does it make any difference?

Basically I'd rather just tap 1/4 bsp as I have a 1/4 bsp tap to hand...

Sorry if it's a bit basic...

 

[Tmoose]

BSP is a straight, non-sealing thread, that requires a fitting with a face seal feature, like an o-ring to effect a seal.

BSPT is tapered, and uses the taper to jam and seal.

I think there is a combination that can still seal, like >>maybe<< a BSPT plug in a BSP tapped hole.

 

[mtrehy]

Thanks,

I guess if I only tap the gallery 15mm deep and wind the socket set screw in, until it gets tight where the thread has stopped and put a bit of hydraulic seal or loctite in it it's got to be ok?

Does anyone else know about that bspt bsp combo?

 

[patprimmer]

I normally use BSPT taps, but BSPT plugs work OK in existing straight BSP holes. I always use Loctite 525 or 515 to seal threads. It works great.

Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Warpspeed]

I have successfully used BSPT plugs in parallel BSP holes, because like many people I already have the tap.

Using Locktite or some other similar thread sealer is absolutely vital with a tapered thread, or it will slowly weep oil forever.