Posting here rather than in a general forum, because I trust the people here.
I'm making eight M10 threaded holes on the bottom side of my lathe bed, for fastening a taper attachment. The material is high quality cast iron.
Because of the shape of the casting, I have two choices:
(1) Make blind tapped holes about 20mm deep, or
(2) Make through holes, and tap them.
I would like to do (2), but the problem is, the shape of the casting is irregular, so the hole will pierce "through" on part of the boundary circle, and remain in the casting on the other part.
I think the last time I broke a tap was in exactly this situation. Once the tap got into the region where half the hole was in metal and half was in air, it twisted and broke.
So is a blind tapped hole the right thing?
Cheers, Bruce
I'm making eight M10 threaded holes on the bottom side of my lathe bed, for fastening a taper attachment. The material is high quality cast iron.
Because of the shape of the casting, I have two choices:
(1) Make blind tapped holes about 20mm deep, or
(2) Make through holes, and tap them.
I would like to do (2), but the problem is, the shape of the casting is irregular, so the hole will pierce "through" on part of the boundary circle, and remain in the casting on the other part.
I think the last time I broke a tap was in exactly this situation. Once the tap got into the region where half the hole was in metal and half was in air, it twisted and broke.
So is a blind tapped hole the right thing?
Cheers, Bruce