There are many different types of countersinks for when you want a screw head to rest flush or below a surface. If you want to sink screws to a consistent depth, you could just use a drill press, but a countersink with a depth stop might offer better results.
If the surface is already sanded or finished and you don’t want to damage it, you can even buy countersinks with adjustable and non-marring bearing depth stops that stop spinning once they come in contact with the material. In this post we talk about two such products.
Advertisement
Amana Tool Carbide-Tipped Countersink
Amana Tool makes one of these non-marring countersinks. Their carbide-tipped 82° countersinks feature a depth stop that is mounted on a no-thrust ball bearing that will stop spinning when it contacts the workpiece surface.
The depth stop can be adjusted to make a countersink anywhere from 3/64″ to 3/8″ deep, a range which is shallow enough for flush-mounting and deep enough to accommodate a plug to cover the screw entirely.
Amana Tool does not specify what the depth stop is made from, but it looks like brass, a typical non-marring metal alloy. Amana says that it won’t scratch, burn, or mar surfaces.
The position of the carbide-tipped M2 high speed steel drill bit can also be adjusted with respect to the countersink cutter, to make the perfect length pilot hole for the screw you’re using.
These countersinking bits have a quick-release-style 1/4″ hex shank and are available in drill sizes that match common screw diameters: 1/8″, 3/32″, 5/32″, 9/64″, and 11/64″. The first four sizes come with a 3/8″ diameter-double winged countersink cutter head, and the largest size comes with a 1/2″ double-winged cutter head.
These countersinks aren’t cheap – they’ll run you between $36 and $39. You can purchase them with free shipping from both Amazon and Tools Today.
Buy Now (via Amazon)
Buy Now (via Tools Today)
Milescraft Colt ZeroMark Countersink
Milescraft sells another non-marring countersinking option, the Colt ZeroMark countersink bit. These German-made bits have a plastic bearing-mounted depth stop.
The depth stop features two slots which allow you to view the drill bit and countersinking head while they’re working. It is also adjustable from 0″ to 11/16″, and has a handy scale on the shaft that’s marked in both metric and imperial.
As with the Amana Tools countersinks, you can also adjust the depth of the drill to the screw size.
Colt ZeroMark bits have a hex quick-connect shank and come in three drill sizes: 1/8″, 5/32″, and 1/4″. Each is rated for up to 1400 RPM.
These bits are just a little bit easier on the wallet, as their prices range from $25 to $30 at Amazon (with Prime Free Shipping).
Buy Now (Colt ZeroMark Countersinks via Amazon)
Below is a short video describing the Colt ZeroMark countersinking bits and showing them in action:
Usage Note
These types of countersink drill bits, which incorporate a pilot drill bit and separate countersink cutter, are typically designed for use with wood materials. Neither of the two brands discussed here explicitly say that their non-marring countersinks should only be used on wood materials, but it might just be an implicit understanding.
We would not recommend the use of these in anything other than wood, but the manufacturers don’t exactly say you can’t.
cody says
I’ve had really good luck with Snappy countersink bits they are easy to use and made in the USA!
Benjamen says
Interesting Stuart sent me a link to the snappy countersinks. I have the really cheap Milescraft version and while they work they don’t leave the cleanest of cuts. That and the bits snap.
Are the snappy bits single or double cutter head? I can’t tell from any of the photos or literature.
cody says
A double cutting head. They are really sharp and can even countersink into thick aluminum plates for screws.
Paul says
Have you used or heard of the SlipStop from Platte River tools (from Woodworker’s Supply) or a Lee Valley low friction stop (Lee Valley part # 66J40.35). It looks like SlipStop makes a stop for forstner bits but I have not found them online yet and the LV countersink is carbide tipped. I was looking at investing in one of those two systems. Thank you for the heads up on these to look at as well.
Benjamen says
I just got a chance to look at your suggestions. The Platte River SlipStop bits look like a good depth stop solution for regular (non-countersinking) drill bits. I have similar depth stops (normal marring type though) I don’t like the single set screw design. the set screw always seems to find one of the flutes and the whole stop goes cockeyed and won’t stay in place. Maybe it’s just the low quality stops I have.
The Lee Valley countersinks are another good choice to keep in mind. I would like to see more details on how the stop is free spinning, it doesn’t look like there is enough room for a bearing.
fred says
I bought a set of these in 2013 – and they work very well.
Amana – under their Timberline brand also make flat-bottom counter-bore bits. These come in sizes for No.4 through No.16 screws. There are 7 sizes, Amana/Timberline part numbers 630-100 through 630-700. They are available at Router Bit World and other sources.
Other bits that may be of interest are FastCap’s DBCB916 – which is designed to cut a recess for their 9/16 caps – but it has other uses.
Smart Bit (Starborn Industries) also make flush-mount bits designed for decking:
http://www.manasquanfasteners.com/decking_screws_smartbit
Yadda says
Never realized such existed. Cool gear.
Nathan says
very nice find – might give a whirl.
Robert says
As a heads up, I believe that the non-marr depthstop used on the colt countersinks are the same as Star-M. They can be ordered, separately, in many sizes.
fred says
The Star-M drill depth stops (made in Japan) seem to come in 20 different (metric sizes – from 3mm to 30mm. A 20 piece set will “set you back” $200
http://www.thebestthings.com/newtools/star_m_depth_stop.htm
Ken says
Indeed, Colt purchases the depth stops from our Japanese office, however, their set is pretty nice with the depth markings and the interchangeable bits. The depth stops alone are compatible with our auger bits – just use the appropriate diameter, and make sure you tighten the set screw on the flutes, not the lands.
ktash says
Great post, Benjamen! These are on my to buy list. Not sure which brand yet.
Mike says
I have been using both the Amana and Milescraft countersinks with depth stops regularly for over a year – thousands of holes. They both work, but there is no question that the Amana is a superior product. The bearing on the Amana works flawlessly, and the carbide countersink leaves a very clean hole. The setscrew on the Milescraft is excessively long and hits your fingers if you are not careful to avoid it. Pay the few extra dollars and get the Amana – you won’t regret it. Thanks for the very useful post.