same as Carldelo has said ...
Posted by: pilotwingz on Oct-17-13 12:23 AM (EST)
-- Last Updated: Oct-17-13 12:51 AM EST --
..... generally termed "Chisle point" or "Twist drill" bits are the type of bit most people (who haven't familiarity with the array of drill bits available) , would think of when they hear the words , drill bit .
It is common practice to drill a "pilot hole" with a smaller size Chisel point bit , and then graduate with a larger (and larger again if req.) size to achieve the desired finish bore size .
This process although common practice is not required , and in truth makes no difference what so ever in the satisfactory completeion of a bored hole ... but do it that way if it makes you more confident .
Chisel point bits are not all the same . They have varying tip angles , varying chisel angles , and differing rates of flute (twist) . Different materials being drilled by Chisel point bits (because of the materials properties) , are best drilled by the proper Chisel point bit designed for the specific material ... but that gets into a more specialized aspect of boring holes , and "generally" not so important to the everyday guy/gal with a drill in their hand .
I will offer you one tip regardless the bit you decide to use ... take a center punch (pointy object) and mark a respectable dent in the exact center of where you want your bit centered . Just "tap" the center punch with a hammer to make the mark .
For what you want to do , boring a 5/8" hole through a Royalex hull , no matter which bit you decide to use ... the results will all be resonably the same if you use a "backer block" held tight up against the inside .
Time to drill your hole now , and not worry too much , it's going to be OK even if it's not perfect , it will be fine . I would use the Forstner , but it's not a mandatory requirement , they all work well enough for your needs .
The most important thing about any bit ... is that it's fresh and sharp . Boring holes with dull bits is improper practice and can leave less than desired results ... or worse !!
ps., ... I want to renage a tad on what I've said to you . You "Can" use a tiny weenie pilot hole for your operation , such as a Chisel point 1/32nd size . This will not effect how a Forstner , Brad point , or larger Chisle point works ... what it will do is allow you to know exacly where to hold the "backer block" (chunk of 2x4 , etc.) so you don't drill into the hand holding the block by mistake !! ... You understand what I just said , right ?? ... This same tiny pilot could act as your center punch as well .
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