Thread size of drag pins for rear callipers

[mrtask]

I've managed to munch the thread in the rear calliper for one of the drag pins. Can anybody tell me what size thread cutting tool I need to obtain to fix it? Hope somebody can help!

 

[harveyp6]

It's a 5/16" fine thread. My initial thoughts were UNF, but comparing the drag pin to a 5/16 UNF bolt, they're close, but I don't think they're the same, so maybe it's a BSF they've thrown in there just to confuse matters. If you're going to a decent tool suppliers, take the drag bolt with you, and they should have thread guages so they can identify the thread, and sell you the correct tap.

 

[mrtask]

5/16" UNF it was indeed. Thank you for your invaluable help Harvey. Thanks too to Netty from Mini Manufaktur who kindly lent me the right tap today. Nice bloke, excellent workshop-come-museum devoted to proper Minis, none of these hideous modern things.

 

[harveyp6]

It's a 5/16" fine thread. My initial thoughts were UNF, but comparing the drag pin to a 5/16 UNF bolt, they're close, but I don't think they're the same, so maybe it's a BSF they've thrown in there just to confuse matters.

5/16" UNF it was indeed. Thank you for your invaluable help Harvey. Thanks too to Netty from Mini Manufaktur who kindly lent me the right tap today. Nice bloke, excellent workshop-come-museum devoted to proper Minis, none of these hideous modern things.

Obviously very close to UNF then. In my defence the caliper bolt I had was in perfect condition, the UNF bolt I checked it against, not so. More than likely just stretched enough to make them appear that little bit different. Glad you got it sorted.