Understanding Helicoil dimensions ???

[Mr Mackay]

I am somewhat confused , as I have been looking for a 1/2 inch BSP insert for a Bauer slurry pump that I have !
Ordered 3 of these 1/2" BSP X 1-1/2D Thread Repair Inserts
https://www.zoro.co.uk/shop/materials-and-maintenance/thread-repair/1/2"-bsp-x-1-1/2d-thread-repair-inserts/p/ZT1061503X?utm_source=google&utm_campaign=pla+|+Materials & Maintenance&utm_term=ZT1061503X&utm_medium=pla_css_2&targetid=aud-697738399087la-392537325346&loc_physical_ms=9041093&dev=c&gclid=EAIaIQobChMIkISJ2uWO7QIVwwZ7Ch2TnAtQEAQYASABEgIHzPD_BwE
I assumed the 1/2 " BSP in the description relates to the interior measurement but it does not as the supplied Helicoil I received ,is approx 7/8ths " BSP
But obviously it does not because the repair kit I ordered 6 months ago had the same oversized inserts ,(and I will refit the brass plug which is 1'2 bsp

Having never used the things before , I understand how they work ,but is it possible to get a 1/2 BSP repair thread??
Cheers folks

 

[Mr Mackay]

Thinking more about it ,I would be better off sacrificing the plug and getting a metric plug ,or unc ,unf ,as thats the 3 sizes of helicoil on offer ?? Not sure where the bsp thing comes in the description

 

[Ley253]

Thinking more about it ,I would be better off sacrificing the plug and getting a metric plug ,or unc ,unf ,as thats the 3 sizes of helicoil on offer ?? Not sure where the bsp thing comes in the description

Its a long time since I used them, so this may be way out! If you tap the hole with the correct helicoil tap, then screw in the insert, I believe it will compress to the correct size. I never had any problems just used the tap and inserting tool .

 

[Mr Mackay]

Doh , I have mismeasured the plug, its 3/8ths and not 1/2 inch

 

[milkloss]

Always confusing when a 1/2 bsp is actually closer to 3/4 inch across the threads.... I have a chart saved to give me guidance when the brain throws a wobbly. I don't think this is the trouble you're having though

 

[Mr Mackay]

Oh believe me it is !! I have assumed a 3/8ths BSP is 1/2 ins - I should know by now but , hell , if I dont get it wrong sometimes