Drill/Countersink combo

**FenceFurniture** · 9th March 2012, 08:39 PM

Not sure where to post this one - maybe we need a drilling forum?

I have by now tried a multitude of drill/countersink combinations and all of them have had fatal problems:
Chinese types that are locally available: absolute rubbish that wobble like crazy, go blunt if you look at them too hard
P&N no doubt Chinese and with similar characteristics to above
Colt ZeroMarks supposedly the beezkneez but failed miserably on a number of fronts (drill bit too short, countersinks are 60 degrees more often than 82 deg (EH?), impossible to change the length due to something like rust inside the shank, and wobbly. WILL NOT drill into hardwood without enormous pressure which makes the bit slip (good eh?). They do at least have a single edge CS flute which leaves a nice CS hole. Prolly the biggest problem with them is that they are completely the wrong sizes - you can PUSH (with nil resistance) an #8 screw through the hole that an #8 gauge ZM drills. They are actually 2 sizes out - #8 is for #10 screws!!!
InstyBit made in Taiwan, actually pretty well made, but are specifically for decking and therefore the bit is too short, and the CS which is not adjustable goes too deep (Ok for a deck but not for other things). I think (from memory) the sizes were also incorrect, but can't be certain until I try it again. Hell expensive for what they are.

I'm waiting on a set of the "ordinary" Drill/CS combos to arrive from Colt, but they are the same design as most of the others, and I expect them to wobble.

So.......anyone ever found a REALLY GOOD combo? The American Fullers? Any that Lee Valley sell?

I believe I can design a good one that doesn't have an adjustable CS depth (but drill depth would be adjustable, as it must be). My thoughts on the CS depth are that the top of the screw should be 1mm below the timber surface. What are your thoughts on that? Having the CS non-adjustable means one less grub screw (which is what puts the balance out and gives it the wobbles). I like the idea of the depth stop that stops rotating when the business is done (ZeroMark and InstyBit). Unfortunately the ZM has two gaps in the rotating plastic stop which catch on the sides of the timber if you are drilling the edge (narrower than the dia of the depth collar). The InstyBit does not have the gaps, and would indeed be a good tool if the depth of the CS hole was shallower. As I recall it didn't wobble very much at all.

I think the drill bit should be a Brad Point, because even though the entry hole gets replaced by a CS, there may well be exit wounds to consider.

Any thoughts on this?

**Stewie D** · 13th March 2012, 04:46 PM

Have you tried asking some of the kitchen hardware supply firms like Lincoln Sentry FF ?
They used to sell this type of bit as they were used in cabinet manufacture.
I bought some American ones ( pack of ten I think ) over twelve years ago and they were very good.
I cannot remember the make though.
Or maybe email one of the American retail outlets and ask whether theirs are US or Chinese made.

Stewie

**FenceFurniture** · 13th March 2012, 05:18 PM

G'day Stewie

I suppose I could try one of the WL Fullers that Carbatec sell, but they all look like the same style that use grub screws (and they are half the problem - balance - slipping - stripping)

**fubar** · 13th March 2012, 07:46 PM

I have been using the snappy range for 6-7 years with good results
Make it Snappy Countersinks
which were purchased from my local tool supplier.
Have recently been using some bosch ones also purchased from same supplier with ok results

**FenceFurniture** · 13th March 2012, 09:01 PM

Thanks fubar, certainly they're cheap enough to give a spin. Do they wobble? Looks like they don't have overall depth control, just the drill - what's the max drill bit length you can get?

**fubar** · 13th March 2012, 11:08 PM

that was usa prices I havent bought them for under $40
They take standard drill bits
I havent needed to go longer than that Suppose you could fit longer shanked bits.
the countersink bit can be positioned anywhere on the drill bit
havent had wobble except when blunt after using on ali but they sharpen up ok

**son_of_bluegras** · 14th March 2012, 10:31 AM

I have and like this set from Fuller. Price has gone up since I bought my set. I imagine you can find other dealers, this just happens to be the site I found a set on.

It is for tapered screws.

Fuller No. 10 Quick Change Tapered Drill Bit Set

**FenceFurniture** · 14th March 2012, 10:47 AM

Originally Posted by son_of_bluegras

I have and like this set from Fuller. Price has gone up since I bought my set. I imagine you can find other dealers, this just happens to be the site I found a set on.

It is for tapered screws.

Fuller No. 10 Quick Change Tapered Drill Bit Set

No wobblies? It's the thing that gets me the most because you end up with a loose fitting screw hole. How well do they lock for depth adjustment/slippage? It's probably a thing curious to our crazy hard timbers, but if the drill is not much good then you need a ton of pressure for penetration which causes slippage. That's why I think they should be Brad Points of excellent quality.

I presume the Fullers have a flat ground onto the side of the drill??

I really do believe that toolmakers should be using Oz timbers for testing, because at least they'll have tested "worst case scenario"! I even had a situation recently where even a fabulous Liogier Hand Stitched rasp had difficulty on a particular species.

**elanjacobs** · 14th March 2012, 10:25 PM

+1 for Snappy. We use the 9/64" at work with Sutton Blue Cobalt HSS bits which is perfect for most screws up to 60-ish mm long. Can't imagine you'd need longer than that. Cuts well in Jarrah and Red Gum but MDF and other abrasive stuff wears the edge fairly fast - they're not HSS
Never wobble, the grub screw holds like a vise and a quick touch on the grinder gets them sharp again.
Slightly premium price but you won't need to buy another for a long time.

**lesmeyer** · 14th March 2012, 11:20 PM

I use the set that Lee Valley sell. Have also spare components as I have drilled many holes and need to replace the drill bits from time to time. I mostly use the 2 smallest sizes. The quality is reasonable and the holes+countersink is just perfect. I do not bother with the countersink depth setting and always eye the depth. The drill bit depth is adjustable and stays put even when drilling into Jarrah. The taper of the drill bit ensures that the screw is seated perfectly.
Les

**son_of_bluegras** · 15th March 2012, 10:39 AM

Originally Posted by FenceFurniture

No wobblies? It's the thing that gets me the most because you end up with a loose fitting screw hole. How well do they lock for depth adjustment/slippage? It's probably a thing curious to our crazy hard timbers, but if the drill is not much good then you need a ton of pressure for penetration which causes slippage. That's why I think they should be Brad Points of excellent quality.

I presume the Fullers have a flat ground onto the side of the drill??

I really do believe that toolmakers should be using Oz timbers for testing, because at least they'll have tested "worst case scenario"! I even had a situation recently where even a fabulous Liogier Hand Stitched rasp had difficulty on a particular species.

I haven't had a problem with wobbling. Like I said these are for tapered screws so the drill bit is tapered.

**FenceFurniture** · 15th March 2012, 10:46 AM

Thank you to all who have replied so far. It sounds like the Fullers and Snappy need a workout.

The tapered drill for Fullers sounds good, but on the other hand the locking system on Snappy sounds very good, and with the ability to put virtually any drill bit in, which for me would be a Brad Point.

Cheers, Brett

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