[AT] Russian Metric uses BSPP was Thought to ponder

[James Peck]

I added  an oil pressure gauge to my long gone 80 VW. I used a 1/8  BSPP to tube fitting from the Festo product line into an already tapped port on the block. That is when I learned that German metric uses BSPP straight thread fittings. I had not known that Russian metric did the same. We have discussed that Belarus is not Russian but I bet the practice came from the Soviet era.

Later, I worked for a company that used BSPP fittings on the hydraulic lines to shift Reaction Injection Molding mix head plungers.

Sometimes people use Teflon tape on the straight threads not knowing that all the sealing is done by the o ring.

[Cecil Bearden] Metric fasteners are the easiest to cross thread for me.  I really have to be careful on my ATV's with the aluminum cases.  My Belarus tractors are not a real problem.  However, the British Straight pipe thread on the hydraulic fittings is a real pain to keep from cross threading..

Cross threading is easier if you start the fastener with the impact wrench. If you start the fastener with your fingers you feel the cross threading.