|Goran Hosinsky||04/12/2010 15:31:01|
|41 forum posts||There seems to be two basic HSS drill bit types, the rolled one and the ground one, the second being somewhat more expensive. What is the difference in use?|
|Speedy Builder5||04/12/2010 16:03:54|
|2416 forum posts|
Never come accross a rolled drill bit, just plain machined, and machined with clearance lands right the way up the drill on the edges of the spiral.
|Goran Hosinsky||04/12/2010 16:51:35|
|41 forum posts|
Perhaps I am using the wrong terms but what I seen in the catalogues are
Rolled high speed, straight shank HSS drill bit
HSS fully ground drill bits,
21468 forum posts
The rolled ones are a cheap basic form of manufacture, OK for a bit of DIY around the house but they are not as good as fully ground bits being more likely to wander, fracture of cut over/under size.
The main flute pattern is rolled and then the edges ground whereas a fully ground bit has the flutes and edges ground
|larry Phelan||25/08/2017 17:33:02|
544 forum posts
I have some rolled drill bits and never have any problem with them.
|Clive Hartland||25/08/2017 22:46:57|
2729 forum posts
There was a programme on Discovery about drills being manufactured and they showed the flutes being milled both at the same time. The profiles of the flutes ground into the special cutters.
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