Zero flute 82° Countersink bits

[LCHIEN]

Bought these a few years back, they are the best, cleanest cutting countersink I know. I call them zero flute or wormhole countersinks. AKA Single end countersink, cross-hole countersinks.

Left - normal fluted countersink, right, zero flute Countersink:



They don't chatter so they leave a very clean bevel. I put one on an extension to match the length of regular bits so I wouldn't have to adjust table height (and possibly change the drill axis centering) when switching to the countersink.

Work well on wood of all kinds and aluminum. Matches the 82° bevel of standard flat head screws.

Just used the real skinny one to countersink some mounting holes on a T-track.

[twistsol]

I have a couple of those that came in a bit set I bought many years ago. I had no idea what they were and they sat unused for a long time. The two I have are small and are useful only for #6 and #8 screws.

[leehljp]

I have one (somewhere) and have used it before. It did well. I see a set on Amazon for about $17 for a set of 4 and there are a couple of cobalt sets for around $40.00. I won't be around long enough to enjoy a good cobalt set. I might order the $17 set from Amazon.

HF has a set of 3 for $10.00, but they have the hex shank. in general I have found hex shanked bits and items from HF to be "ok" but not very good for more precision needed places.

[LCHIEN]

forget the hex shank, too much play and runout to use in a power screw driver.

[Jim Frye]

I have a single flute counter sink and an old set of Craftsman drill bits that drill pilot, shank, and countersink in one pass. Since I stopped using screws in wood assemblies almost twenty years ago, those tools have disappeared from quick access in the shop. The countersink is stuck in an upper corner of the peg board wall and I honestly don't know where the drill bit set is anymore.

[Slik Geek]

Never seen countersinks like that before. Have you ever had to sharpen them? I'm curious how hard/easy it would be.

[LCHIEN]

never felt the need to sharpen them.

[leehljp]

I have a single flute counter sink and an old set of Craftsman drill bits that drill pilot, shank, and countersink in one pass. Since I stopped using screws in wood assemblies almost twenty years ago, those tools have disappeared from quick access in the shop. The countersink is stuck in an upper corner of the peg board wall and I honestly don't know where the drill bit set is anymore.

Curious about one thing: What do you use for fastening - nails, pegs, biscuits?

I started using screws and quit using nails (hand hammered nails that is) about 30 years ago, and use the pocket screws when possible. I quit pegs after banging my thumb when trying to over-tap a peg into a hole about 30 years ago. Man, that hurt!

[Jim Frye]

Curious about one thing: What do you use for fastening - nails, pegs, biscuits?

I started using screws and quit using nails (hand hammered nails that is) about 30 years ago, and use the pocket screws when possible. I quit pegs after banging my thumb when trying to over-tap a peg into a hole about 30 years ago. Man, that hurt!

I use bamboo pegs (skewers) inserted after the glue joint cures to lock the joint from coming apart. It's time consuming, but so far, seems to be an alternative that works. The method can be used on virtually any wood joint. I've even used it to lock dovetail joints. I do use biscuits for panel glue ups and carcass construction, but will use the pins to lock carcass assemblies even with biscuits.

[LCHIEN]

OK several questions were asked.

First of all, I do use the all-in one countersinks when drilling for holes for screws. Enough holes to make it worth setting the length and stops. They work well. And frankly the screw covers the bevel so it really doesn't matter how clean the bevel looks.


I use the zero flute ones where making holes that show. Holes in handles for hanging tools and fixtures. Holes in peg board games to make it easier to enter the hole with the peg and also look clean and finished. Also for equipment like jigs and adjustable stands where a peg can be put in a series of holes to adjust height or depth.



Curious about one thing: What do you use for fastening - nails, pegs, biscuits?
I use Pneumatic brad nails and pins, glue, screws, PH screws, biscuits, and dowels, depending on what I'm building. I like having the choice and there are reasons for using any of them besides the excuse that I have them all. I seldom use hammered nails except when repairing my fence.

Never seen countersinks like that before. Have you ever had to sharpen them? I'm curious how hard/easy it would be.
Never had to sharpen them, so I don't know. DOn't seem to need it yet.
As for finding them, they are everywhere. Google Zero Flute Countersinks:

[LCHIEN]

Picture from Rockler showing effect of chattering (left)

[LCHIEN]

FWIW, Europeans M series metric flat head screws tend to be 90° but US flat head wood screws and SAE/ANSII machine flat head screws are all 82° countersink heads.

Lots of eBay and Amazon and Temu countersink items will list 90 degrees but for US hardware 82° is the correct one as most of us here are US based. A lot of ads for Temu countersinks for example don't specify 82 or 90 but give all the dimensions in mm so in my book they are probably 90°.

[Jim Frye]

FWIW, Europeans M series metric flat head screws tend to be 90° but US flat head wood screws and SAE/ANSII machine flat head screws are all 82° countersink heads.

Lots of eBay items will list 90 degrees but for US hardware 82° is the correct one.

Which begs the question: WHY?

[LCHIEN]

https://www.reddit.com/r/MechanicalE...dom_screws_82/