Editor in Chief Bill | 29 Mar 2016 12:48 p.m. PST |
If I drill a hole with a standard drill bit, the bottom of the hole is not flat but pointed. Is there a drill bit which can produce a flat bottom to the drilled hole? |
jfleisher | 29 Mar 2016 12:53 p.m. PST |
You'd be looking for a Forstner bit, but I'm not sure how small they make those, 1/4" is the smallest I have seen. How big is the hole? |
Balin Shortstuff | 29 Mar 2016 12:53 p.m. PST |
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14Bore | 29 Mar 2016 1:23 p.m. PST |
How small because not sure the smallest Forstner can go? |
14Bore | 29 Mar 2016 1:26 p.m. PST |
If super small you could use a normal bit then take one same size and loose the point just to finish the bottom. |
coryfromMissoula | 29 Mar 2016 1:53 p.m. PST |
For 1/4" or smaller I first drill all but the last bit of the hole and then finish it with a bit that has had the end ground flat. |
Mugwump | 29 Mar 2016 3:47 p.m. PST |
I used to have to cut off the point (cutting wheel) and then relieve the flat bottoms to allow chip clearance. If you can hand sharpen a drill bit you should be good. |
miniMo | 29 Mar 2016 4:00 p.m. PST |
For modelling work, I jsut use regulare bits, then stuff a bit of putty into the bottom of the hole if I need to make it flat. |
tberry7403 | 29 Mar 2016 4:15 p.m. PST |
If you are doing bases you could always drill completely through the base then glue a thin piece of metal/plastic/wood/cardboard to the bottom of the base. |
Mick the Metalsmith | 29 Mar 2016 6:22 p.m. PST |
Jeweler's burs come in many shapes and sizes. I have some flat squarish burs that are only 3mm in diameter. Rio Grande Jewelry supplies can help. |
Steve at The Vault | 29 Mar 2016 7:46 p.m. PST |
Use an end mill. It's just a drill bit with no point, just drill slow. |
bsrlee | 30 Mar 2016 6:43 a.m. PST |
For wood you can get 'brad point' drill bits. Tiny center point and spurs on the periphery gives the hole as flat a bottom as you are likely to see and a fairly neat entry hole. They comes in sizes from 1/16"(1.5mm) up to around 1/2"(13mm), cheap sets usually have 1/16 to 3/8 but you do get what you pay for (limp spaghetti comes to mind). Forstner bits are good but clog and overheat if you are drilling deep holes and don't keep clearing the waste from the bit – HSS (high speed steel) bits are not affected by heating but a lot of on line shops won't tell you what their Forstner bits are made of, Lee Valley being an notable exception. |
Editor in Chief Bill | 31 Mar 2016 11:46 a.m. PST |
How big is the hole? 5/32, drilling into pewter |
14Bore | 01 Apr 2016 1:32 p.m. PST |
Regular twist bits are in two degree sizes 118 or 135, since so small would a shallow degree work? Never drilled pewter but should be softer than steel which is what I mostly dill into. |