Sj250 for drill bits?

[AndrewLee]

Got my Japanese stone through the post this morning so very excited to try it out tonight after work

Is there a point to further honing a drill bit to 4000 grit with the SJ250 or will the regular stone suffice?

[RichColvin]

I have found the SB stone to do a fine job.  I've never even taken it to the fine grind (1000 grit), & my bits work superbly.

[AndrewLee]

Rather than starting yet another thread, but can anyone trouble shoot my drill bit sharpening woes?

I can now make my newly four faceted bits look good, they look like what theyre supposed to look like. HOWEVER, my drill bit still wanders when I try to drill with it.. Anyone wiser than me know why? I'm thinking if it's beside the bits are cheap Chinese ones or that shouldn't be a major factor.

Cheers,
Andrew

[Stickan]

Hi,
Could you please take a picture of the tip of the drillbit and share here, or send to support@tormek.se?
That would help me and quickly help you out.

Best,
Stig

[SharpenADullWitt]

Also, you might list what your trying to drill!

For instance, metal drilling, is typically done slower and requires in many cases, a point, punched/scribbed on the metal, so the bit doesn't wander.

[Ken S]

Andrew,

I think the Tormek sharpened four facet drill bits are a substantial improvement over conventionally sharpened bits. I do not think they in any way eliminate the need for good drilling practice.While they do not skate as much as regular bits, I would still use a center punch and smaller center drill for precise work.

I am no fan of cheap bits and tools, regardless of their country of origin.

Ken

[Jan]

Got my Japanese stone through the post this morning so very excited to try it out tonight after work

Is there a point to further honing a drill bit to 4000 grit with the SJ250 or will the regular stone suffice?

As I  posted previously, my understanding why the edge stays longer sharp when sharpened on finer grindstone is following: deep scratches in the metal surface, caused by low grit stone, can serve as stress risers, which can initiate fatigue cracks or some other defects near the edge and make the tool life shorter.

For more info please read :
http://forum.tormek.com/index.php?topic=2831.msg14998#msg14998

On the other hand I would not expect that finer grinding will decrease the drill bit wandering problem. It could be on the contrary, because finer grinding lets smaller micro teeth at the cutting edges.

Jan

[Ken S]

Andrew, how did your drill bit sharpening go with the SJ-250?

Ken